Create a shared task to deduplicate logic listing recent TILs

Add two new browsing tasks for popping open latest TIL in browser
Add Deduplicate List While Preserving Original Order as a Unix TIL
2026-07-06 17:20:33 +00:00 · 2026-07-05 18:25:02 -05:00 · 2026-07-05 18:09:31 -05:00 · 2026-07-05 17:55:06 -05:00 · 2026-07-04 17:14:33 -05:00 · 2026-07-03 21:44:35 -04:00
56 changed files with 2425 additions and 1 deletions
@@ -10,10 +10,11 @@ working across different projects via [VisualMode](https://www.visualmode.dev/).

 For a steady stream of TILs, [sign up for my newsletter](https://visualmode.kit.com/newsletter).

-_1756 TILs and counting..._
+_1810 TILs and counting..._

 See some of the other learning resources I work on:

+- [The VisualMode Blog](https://visualmode.dev/blog)
 - [Get Started with Vimium](https://egghead.io/courses/get-started-with-vimium~3t5f7)
 - [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
 - [Vim Un-Alphabet](https://www.youtube.com/playlist?list=PL46-cKSxMYYCMpzXo6p0Cof8hJInYgohU)
@@ -59,6 +60,7 @@ If you've learned something here, support my efforts writing daily TILs by
 * [Linux](#linux)
 * [LLM](#llm)
 * [Mac](#mac)
+* [Math](#math)
 * [Mise](#mise)
 * [MongoDB](#mongodb)
 * [MySQL](#mysql)
@@ -164,9 +166,11 @@ If you've learned something here, support my efforts writing daily TILs by
 ### Claude Code

 - [Allow Edits From The Start](claude-code/allow-edits-from-the-start.md)
+- [Distinguish Sessions With Different Colors](claude-code/distinguish-sessions-with-different-colors.md)
 - [Monitor Usage Limits From CLI](claude-code/monitor-usage-limits-from-cli.md)
 - [Open Current Prompt In Default Editor](claude-code/open-current-prompt-in-default-editor.md)
 - [Resume Specific Session](claude-code/resume-specific-session.md)
+- [Stash The Current Prompt To Send Another First](claude-code/stash-the-current-prompt-to-send-another-first.md)

 ### Clojure

@@ -237,6 +241,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Check For Cached Site Assocation File For iOS](devops/check-for-cached-site-association-file-for-ios.md)
 - [Check The Status of All Services](devops/check-the-status-of-all-services.md)
 - [Check The Syntax Of nginx Files](devops/check-the-syntax-of-nginx-files.md)
+- [Cloudflare Allows CNAME For Apex Domain](devops/cloudflare-allows-cname-for-apex-domain.md)
 - [Connect To An RDS PostgreSQL Database](devops/connect-to-an-rds-postgresql-database.md)
 - [Default Rails Deploy Script On Hatchbox](devops/default-rails-deploy-script-on-hatchbox.md)
 - [Determine The IP Address Of A Domain](devops/determine-the-ip-address-of-a-domain.md)
@@ -360,6 +365,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Determine Absolute Path Of Top-Level Project Directory](git/determine-absolute-path-of-top-level-project-directory.md)
 - [Determine The Hash Id For A Blob](git/determine-the-hash-id-for-a-blob.md)
 - [Diffing With Patience](git/diffing-with-patience.md)
+- [Display All Git Log Entries In My Local Timezone](git/display-all-git-log-entries-in-my-local-timezone.md)
 - [Dropping Commits With Git Rebase](git/dropping-commits-with-git-rebase.md)
 - [Dry Runs in Git](git/dry-runs-in-git.md)
 - [Exclude A File From A Diff Output](git/exclude-a-file-from-a-diff-output.md)
@@ -403,6 +409,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Move The Latest Commit To A New Branch](git/move-the-latest-commit-to-a-new-branch.md)
 - [Override The Global Git Ignore File](git/override-the-global-git-ignore-file.md)
 - [Pick Specific Changes To Stash](git/pick-specific-changes-to-stash.md)
+- [Programmatically Grab SHA For Head Commit](git/programmatically-grab-sha-for-head-commit.md)
 - [Pulling In Changes During An Interactive Rebase](git/pulling-in-changes-during-an-interactive-rebase.md)
 - [Push To A Branch On Another Remote](git/push-to-a-branch-on-another-remote.md)
 - [Quicker Commit Fixes With The Fixup Flag](git/quicker-commit-fixes-with-the-fixup-flag.md)
@@ -461,7 +468,10 @@ If you've learned something here, support my efforts writing daily TILs by
 ### GitHub

 - [Access Your GitHub Profile Photo](github/access-your-github-profile-photo.md)
+- [List PRs Awaiting Your Review](github/list-prs-awaiting-your-review.md)
 - [Open A PR To An Unforked Repo](github/open-a-pr-to-an-unforked-repo.md)
+- [Open File To Specific Line In Browser](github/open-file-to-specific-line-in-browser.md)
+- [Process JSON Output From gh With jq](github/process-json-output-from-gh-with-jq.md)
 - [Target Another Repo When Creating A PR](github/target-another-repo-when-creating-a-pr.md)
 - [Tell gh What The Default Repo Is](github/tell-gh-what-the-default-repo-is.md)

@@ -615,6 +625,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Get The Response Status From An Axios Error](javascript/get-the-response-status-from-an-axios-error.md)
 - [Get The Time Components Of A Date](javascript/get-the-time-components-of-a-date.md)
 - [Get The Time Zone Of The Client Computer](javascript/get-the-time-zone-of-the-client-computer.md)
+- [Get User's Preferred Language From Browser](javascript/get-users-preferred-language-from-browser.md)
 - [Globally Install A Package With Yarn](javascript/globally-install-a-package-with-yarn.md)
 - [Globally Install Specific Version Of PNPM](javascript/globally-install-specific-version-of-pnpm.md)
 - [Immutable Remove With The Spread Operator](javascript/immutable-remove-with-the-spread-operator.md)
@@ -715,6 +726,7 @@ If you've learned something here, support my efforts writing daily TILs by

 ### LLM

+- [Count Number Of Tokens In A File](llm/count-number-of-tokens-in-a-file.md)
 - [Send cURL To Claude Text Completion API](llm/send-curl-to-claude-text-completion-api.md)
 - [Use The llm CLI With Claude Models](llm/use-the-llm-cli-with-claude-models.md)

@@ -726,6 +738,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Add A Bunch Of CLI Utilities With coreutils](mac/add-a-bunch-of-cli-utilities-with-coreutils.md)
 - [Capture Screenshot To Clipboard From CLI](mac/capture-screenshot-to-clipboard-from-cli.md)
 - [Check Network Quality Stats From The Command Line](mac/check-network-quality-stats-from-the-command-line.md)
+- [Clean Up Item Layout In Finder Window](mac/clean-up-item-layout-in-finder-window.md)
 - [Clean Up Old Homebrew Files](mac/clean-up-old-homebrew-files.md)
 - [Control Which Monitor App Switcher Appears On](mac/control-which-monitor-app-switcher-appears-on.md)
 - [Convert An HEIC Image File To JPG](mac/convert-an-heic-image-file-to-jpg.md)
@@ -743,9 +756,11 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Open Finder.app To Specific Directory](mac/open-finder-app-to-specific-directory.md)
 - [Prevent Sleep With The Caffeinate Command](mac/prevent-sleep-with-the-caffeinate-command.md)
 - [Quickly Type En Dashes And Em Dashes](mac/quickly-type-en-dashes-and-em-dashes.md)
+- [Read The Lid Angle Sensor For A MacBook](mac/read-the-lid-angle-sensor-for-a-macbook.md)
 - [Require Additional JS Libraries In Postman](mac/require-additional-js-libraries-in-postman.md)
 - [Resize App Windows With AppleScript](mac/resize-app-windows-with-applescript.md)
 - [Resizing Both Corners Of A Window](mac/resizing-both-corners-of-a-window.md)
+- [Reveal Location Of File In Finder.app](mac/reveal-location-of-file-in-finder-app.md)
 - [Run A Hardware Check](mac/run-a-hardware-check.md)
 - [Run AppleScript Commands Inline In The Terminal](mac/run-applescript-commands-inline-in-the-terminal.md)
 - [Set A Window To Its Default Zoom Level](mac/set-a-window-to-its-default-zoom-level.md)
@@ -757,6 +772,10 @@ If you've learned something here, support my efforts writing daily TILs by
 - [View All Windows Of The Current App](mac/view-all-windows-of-the-current-app.md)
 - [Write System Clipboard To A File](mac/write-system-clipboard-to-a-file.md)

+### Math
+
+- [Generate Permutations Of All Valid 9-ball Racks](math/generate-permutations-of-all-valid-9-ball-racks.md)
+
 ### Mise

 - [Create Umbrella Task For All Test Tasks](mise/create-umbrella-task-for-all-test-tasks.md)
@@ -845,6 +864,7 @@ If you've learned something here, support my efforts writing daily TILs by

 ### pnpm

+- [Avoid Vulnerabilities In New Package Versions](pnpm/avoid-vulnerabilities-in-new-package-versions.md)
 - [Execute A Command From The Workspace Root](pnpm/execute-a-command-from-the-workspace-root.md)
 - [Install Command Runs For Entire Workspace](pnpm/install-command-runs-for-entire-workspace.md)
 - [List The Installed Version Of A Specific Package](pnpm/list-the-installed-version-of-a-specific-package.md)
@@ -1042,22 +1062,47 @@ If you've learned something here, support my efforts writing daily TILs by

 - [Access Instance Variables](python/access-instance-variables.md)
 - [Access Most Recent Return Value In REPL](python/access-most-recent-return-value-in-repl.md)
+- [Access Variables Outside Loop Scope](python/access-variables-outside-loop-scope.md)
+- [Argument Defaults Are Evaluated When Function Is Defined](python/argument-defaults-are-evaluated-when-function-is-defined.md)
+- [Assert Is Only A Development Check](python/assert-is-only-a-development-check.md)
+- [Avoid Modification With Frozen Dataclass](python/avoid-modification-with-frozen-dataclass.md)
 - [Break Debugger On First Line Of Program](python/break-debugger-on-first-line-of-program.md)
 - [Check If Package Is Installed With Pip](python/check-if-package-is-installed-with-pip.md)
+- [Check Precondition Before Click Arg Parsing](python/check-precondition-before-click-arg-parsing.md)
+- [Control Passing Of Time In Tests](python/control-passing-of-time-in-tests.md)
 - [Create A Dummy DataFrame In Pandas](python/create-a-dummy-dataframe-in-pandas.md)
+- [Create A Range Of Descending Values](python/create-a-range-of-descending-values.md)
+- [Deduplicate A List Into A Tuple](python/deduplicate-a-list-into-a-tuple.md)
+- [Define Sequence Of Tests With Parametrize Decorator](python/define-sequence-of-tests-with-parametrize-decorator.md)
+- [Define Typed Class Interface With Protocol](python/define-typed-class-interface-with-protocol.md)
 - [Dunder Methods](python/dunder-methods.md)
 - [Easy Key-Value Aggregates With defaultdict](python/easy-key-value-aggregates-with-defaultdict.md)
+- [Enable Pyright Type Checking In Cursor](python/enable-pyright-type-checking-in-cursor.md)
+- [Get Absolute Seconds From `timedelta` Object](python/get-absolute-seconds-from-timedelta-object.md)
+- [Get Quotient And Remainder In One Operation](python/get-quotient-and-remainder-in-one-operation.md)
 - [Install With PIP For Specific Interpreter](python/install-with-pip-for-specific-interpreter.md)
 - [Iterate First N Items From Enumerable](python/iterate-first-n-items-from-enumerable.md)
 - [Iterate Over A Dictionary](python/iterate-over-a-dictionary.md)
 - [Keep A Tally With collections.Counter](python/keep-a-tally-with-collections-counter.md)
 - [Load A File Into The Python REPL](python/load-a-file-into-the-python-repl.md)
+- [Look Inside Pytest tmp_path](python/look-inside-pytest-tmp-path.md)
+- [Make Dataclass Sortable By Specific Field](python/make-dataclass-sortable-by-specific-field.md)
+- [Make Secure Temp File For Atomic Write](python/make-secure-temp-file-for-atomic-write.md)
 - [Override The Boolean Context Of A Class](python/override-the-boolean-context-of-a-class.md)
 - [Parse Relative Time To datetime Object](python/parse-relative-time-to-datetime-object.md)
+- [Reclassify Certain Packages As Dev Dependencies](python/reclassify-certain-packages-as-dev-dependencies.md)
+- [Set Up Pyright Type Checking In GitHub](python/set-up-pyright-type-checking-in-github.md)
+- [Skip Specific Pytest Test Cases](python/skip-specific-pytest-test-cases.md)
+- [Sort A List Of Dataclass Instances](python/sort-a-list-of-dataclass-instances.md)
+- [Sort Normalized Version Of Data](python/sort-normalized-version-of-data.md)
+- [Start The Debugger When A Test Errors](python/start-the-debugger-when-a-test-errors.md)
 - [Store And Access Immutable Data In A Tuple](python/store-and-access-immutable-data-in-a-tuple.md)
 - [Test A Function With Pytest](python/test-a-function-with-pytest.md)
+- [Turn Method Into Cached Property On Class Instance](python/turn-method-into-cached-property-on-class-instance.md)
 - [Use pipx To Install End User Apps](python/use-pipx-to-install-end-user-apps.md)
+- [Use `__post_init__` For `dataclass` Validations](python/use-post-init-for-dataclass-validations.md)
 - [Use Verbose Flag To Get More Diff](python/use-verbose-flag-to-get-more-diff.md)
+- [Validate Click Option With Callback](python/validate-click-option-with-callback.md)

 ### Rails

@@ -1113,6 +1158,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Customize Paths And Helpers For Devise Routes](rails/customize-paths-and-helpers-for-devise-routes.md)
 - [Customize Template For New Schema Migration](rails/customize-template-for-new-schema-migration.md)
 - [Customize The Path Of A Resource Route](rails/customize-the-path-of-a-resource-route.md)
+- [Define Conditional Routing Logic In Routes File](rails/define-conditional-routing-logic-in-routes-file.md)
 - [Define The Root Path For The App](rails/define-the-root-path-for-the-app.md)
 - [Delete Paranoid Records](rails/delete-paranoid-records.md)
 - [Demodulize A Class Name](rails/demodulize-a-class-name.md)
@@ -1143,6 +1189,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Get The Column Names For A Model](rails/get-the-column-names-for-a-model.md)
 - [Get The Current Time](rails/get-the-current-time.md)
 - [Grab A Random Record From The Database](rails/grab-a-random-record-from-the-database.md)
+- [Halt ActionMailer Delivery With Callback](rails/halt-action-mailer-delivery-with-callback.md)
 - [Handle Named Arguments In A Rake Task](rails/handle-named-arguments-in-a-rake-task.md)
 - [Hash Slicing](rails/hash-slicing.md)
 - [Ignore Poltergeist JavaScript Errors](rails/ignore-poltergeist-javascript-errors.md)
@@ -1404,6 +1451,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Defaulting To Frozen String Literals](ruby/defaulting-to-frozen-string-literals.md)
 - [Define A Custom RSpec Matcher](ruby/define-a-custom-rspec-matcher.md)
 - [Define A Method On A Struct](ruby/define-a-method-on-a-struct.md)
+- [Define A Set Of Class Methods](ruby/define-a-set-of-class-methods.md)
 - [Define Multiline Strings With Heredocs](ruby/define-multiline-strings-with-heredocs.md)
 - [Destructure The First Item From An Array](ruby/destructure-the-first-item-from-an-array.md)
 - [Destructuring Arrays In Blocks](ruby/destructuring-arrays-in-blocks.md)
@@ -1424,6 +1472,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [FactoryGirl Sequences](ruby/factory-girl-sequences.md)
 - [Fail](ruby/fail.md)
 - [Fetch Warns About Superseding Block Argument](ruby/fetch-warns-about-superseding-block-argument.md)
+- [Filter By Type](ruby/filter-by-type.md)
 - [Find The Min And Max With A Single Call](ruby/find-the-min-and-max-with-a-single-call.md)
 - [Finding The Source of Ruby Methods](ruby/finding-the-source-of-ruby-methods.md)
 - [Format A Hash Into A String Template](ruby/format-a-hash-into-a-string-template.md)
@@ -1526,6 +1575,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Update The Gemfile Bundled With Version](ruby/update-the-gemfile-bundled-with-version.md)
 - [Use A Case Statement As A Cond Statement](ruby/use-a-case-statement-as-a-cond-statement.md)
 - [Use dotenv In A Non-Rails Project](ruby/use-dotenv-in-a-non-rails-project.md)
+- [Use Rescue As Part Of Inline Statement](ruby/use-rescue-as-part-of-inline-statement.md)
 - [Use Tap For Better Test Data Setup](ruby/use-tap-for-better-test-data-setup.md)
 - [Using BCrypt To Create And Check Hashed Passwords](ruby/using-bcrypt-to-create-and-check-hashed-passwords.md)
 - [What To Do When You Don't Rescue](ruby/what-to-do-when-you-dont-rescue.md)
@@ -1570,6 +1620,7 @@ If you've learned something here, support my efforts writing daily TILs by

 ### Taskfile

+- [Add Default Task To List All Tasks](taskfile/add-default-task-to-list-all-tasks.md)
 - [Create Interactive Picker For Set Of Subtasks](taskfile/create-interactive-picker-for-set-of-subtasks.md)
 - [Run A Task If It Meets Criteria](taskfile/run-a-task-if-it-meets-criteria.md)

@@ -1643,6 +1694,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [All The Environment Variables](unix/all-the-environment-variables.md)
 - [Apply Successive Filters To Lines In Less](unix/apply-successive-filters-to-lines-in-less.md)
 - [Authorize A cURL Request](unix/authorize-a-curl-request.md)
+- [Browse And Search Help Docs](unix/browse-and-search-help-docs.md)
 - [Cat A File With Line Numbers](unix/cat-a-file-with-line-numbers.md)
 - [Cat Files With Color Using Bat](unix/cat-files-with-color-using-bat.md)
 - [Change Default Shell For A User](unix/change-default-shell-for-a-user.md)
@@ -1672,6 +1724,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Curl With Cookies](unix/curl-with-cookies.md)
 - [Curling For Headers](unix/curling-for-headers.md)
 - [Curling With Basic Auth Credentials](unix/curling-with-basic-auth-credentials.md)
+- [Deduplicate List While Preserving Original Order](unix/deduplicate-list-while-preserving-original-order.md)
 - [Determine ipv4 And ipv6 Public IP Addresses](unix/determine-ipv4-and-ipv6-public-ip-addresses.md)
 - [Diff Two Files In Unified Format](unix/diff-two-files-in-unified-format.md)
 - [Different Ways To Generate A v4 UUID](unix/different-ways-to-generate-a-v4-uuid.md)
@@ -1765,6 +1818,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Print A Range Of Lines For A File With Bat](unix/print-a-range-of-lines-for-a-file-with-bat.md)
 - [Print DateTime Represented By Unix Timestamp](unix/print-datetime-represented-by-unix-timestamp.md)
 - [Print Milliseconds In Human-Readable Format](unix/print-milliseconds-in-human-readable-format.md)
+- [Print Out File With Bat Without Formatting](unix/print-out-file-with-bat-without-formatting.md)
 - [Print Out Files In Reverse](unix/print-out-files-in-reverse.md)
 - [Print The Current Date In Human-Readable Format](unix/print-the-current-date-in-human-readable-format.md)
 - [Produce A Lowercase V4 UUID](unix/produce-a-lowercase-v4-uuid.md)
@@ -1773,6 +1827,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Rename A Bunch Of Files By Constructing mv Commands](unix/rename-a-bunch-of-files-by-constructing-mv-commands.md)
 - [Repeat Yourself](unix/repeat-yourself.md)
 - [Replace Pattern Across Many Files In A Project](unix/replace-pattern-across-many-files-in-a-project.md)
+- [Reverse Each Line Of A File](unix/reverse-each-line-of-a-file.md)
 - [Run A Command Repeatedly Several Times](unix/run-a-command-repeatedly-several-times.md)
 - [Run A cURL Command Without The Progress Meter](unix/run-a-curl-command-without-the-progress-meter.md)
 - [Safely Edit The Sudoers File With Vim](unix/safely-edit-the-sudoers-file-with-vim.md)
@@ -1806,6 +1861,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Use fzf To Change Directories](unix/use-fzf-to-change-directories.md)
 - [Use Negative Lookbehind Matching With ripgrep](unix/use-negative-lookbehind-matching-with-ripgrep.md)
 - [Use Regex Pattern Matching With Grep](unix/use-regex-pattern-matching-with-grep.md)
+- [Use The Readline Keybindings Anywhere](unix/use-the-readline-keybindings-anywhere.md)
 - [View A Web Page In The Terminal](unix/view-a-web-page-in-the-terminal.md)
 - [View The Source For A Brew Formula](unix/view-the-source-for-a-brew-formula.md)
 - [Watch The Difference](unix/watch-the-difference.md)
@@ -2037,11 +2093,13 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Send A Message To A Discord Channel](workflow/send-a-message-to-a-discord-channel.md)
 - [Send A PDF To Your Kindle](workflow/send-a-pdf-to-your-kindle.md)
 - [Set Recurring Reminders In Slack](workflow/set-recurring-reminders-in-slack.md)
+- [Show All Linear Keyboard Shortcuts](workflow/show-all-linear-keyboard-shortcuts.md)
 - [Show Linting Errors In Zed](workflow/show-linting-errors-in-zed.md)
 - [Temporarily Hide CleanShot X Capture Previews](workflow/temporarily-hide-cleanshot-x-capture-previews.md)
 - [Toggle Between Stories In Storybook](workflow/toggle-between-stories-in-storybook.md)
 - [Update asdf Plugins With Latest Package Versions](workflow/update-asdf-plugins-with-latest-package-versions.md)
 - [View A Nicely-Formatted CSV In Terminal](workflow/view-a-nicely-formatted-csv-in-terminal.md)
+- [View Nicely Formatted Markdown From Terminal](workflow/view-nicely-formatted-markdown-from-terminal.md)
 - [View The PR For The Current GitHub Branch](workflow/view-the-pr-for-the-current-github-branch.md)

 ### XState
@@ -2076,6 +2134,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Add To The Path Via Path Array](zsh/add-to-the-path-via-path-array.md)
 - [Create And Jump Into A Directory](zsh/create-and-jump-into-a-directory.md)
 - [Link A Scalar To An Array](zsh/link-a-scalar-to-an-array.md)
+- [List Available Zle Keybindings](zsh/list-available-zle-keybindings.md)
 - [Use A Space To Exclude Command From History](zsh/use-a-space-to-exclude-command-from-history.md)

 ## Usage
@@ -11,6 +11,36 @@ tasks:
    cmds:
      - task --list

+  browse:list:
+    desc: Print deduped, newest-first TIL paths
+    silent: true
+    cmds:
+      - |
+        git log --diff-filter=A --name-only --pretty=format: -- '*/*.md' \
+          | grep -v '^$' \
+          | awk '!seen[$0]++'
+
+  browse:
+    desc: Pick from 5 most recent TILs (fzf) and open in browser
+    interactive: true
+    silent: true
+    cmds:
+      - |
+        FILE=$(task browse:list | head -5 | fzf --prompt="Open TIL: " --height=40% --reverse) || true
+        if [ -n "$FILE" ]; then
+          gh browse "$FILE"
+        fi
+
+  browse:latest:
+    desc: Open the single most recent TIL in the browser
+    silent: true
+    cmds:
+      - |
+        FILE=$(task browse:list | head -1)
+        if [ -n "$FILE" ]; then
+          gh browse "$FILE"
+        fi
+
  notes:
    desc: Interactive picker for notes tasks
    cmds:
@@ -0,0 +1,24 @@
+# Distinguish Sessions With Different Colors
+
+I sometimes have several Claude Code sessions open at once. As I bounce between
+tmux windows, it can sometimes be tricky to tell them apart at a glance. One way
+that Claude Code can help with this is with some light styling. You can change
+the accent color of a session with the `/color` command.
+
+Run it as is and it will choose a random color to set the session to.
+
+Or you can pick from any of the available colors which it will give you a hint
+for if you type a space after `/color`.
+
+```
+/color [red|blue|green|yellow|purple|orange|pink|cyan|default]
+```
+
+I can run the following to set it to cyan:
+
+```
+/color cyan
+```
+
+More details on this kinds of commands can be found in the [_Commands_
+docs](https://code.claude.com/docs/en/commands).
@@ -0,0 +1,25 @@
+# Stash The Current Prompt To Send Another First
+
+I've been working my way through the current cohort of Matt Pocock's [Claude
+Code for Real
+Engineers](https://www.aihero.dev/cohorts/claude-code-for-real-engineers-2026-04).
+The best part about going through a series of videos like this is being able to
+pick up big and small tips and tricks from another person's workflow.
+
+One of the small things I picked up in an early video is the ability to stash
+the current prompt.
+
+Let's say I've gone to the trouble of writing out a detailed prompt, `@`'ing
+some files, and so forth. Then I realize I need first prompt Claude to do
+something else first. Instead of copy-pasting that prompt into my notes,
+deleting it, issuing a different prompt, and then pasting it back in, I can hit
+`Ctrl-s`.
+
+`Ctrl-s` will _stash_ the current prompt, clearing out the prompt input. I can
+then type in something else. Once I hit enter for that new prompt, it will be
+sent to Claude and the stashed prompt will be immediately populated back into
+the input.
+
+Though `Ctrl-s` is mentioned when you hit `?` from within `claude` session, I
+don't see it documented anywhere in their [Interactive Mode
+reference](https://code.claude.com/docs/en/interactive-mode).
@@ -0,0 +1,19 @@
+# Cloudflare Allows CNAME For Apex Domain
+
+If you want to set up a custom root (apex) domain with an app hosting provider
+[like
+Heroku](https://devcenter.heroku.com/articles/custom-domains#add-a-custom-root-domain),
+you're going to need to work with a DNS provider that supports the non-standard
+`ALIAS` records (or something equivalent).
+
+In my case, I have my domain registered with Cloudflare. Cloudflare supports
+this kind of CNAME lookup of an apex domain through [_CNAME
+flattening_](https://developers.cloudflare.com/dns/cname-flattening/).
+
+Unlike other registrars that use a separate `ALIAS` record concept, Cloudflare
+allows you to set up a specialized `CNAME` record. Go into the DNS settings for
+the domain of interest, click "Add Record", and then select `CNAME`. From there,
+instead of entering a traditional subdomain like `www`, you put the `@` symbol
+which tells Cloudflare that this is a record for the apex domain. That record
+will still point to a target like `abc123.herokudns.com` as a more traditional
+`CANME` would do.
@@ -0,0 +1,30 @@
+# Display All Git Log Entries In My Local Timezone
+
+I tend to work with remote teams distributed across across multiple time zones.
+In that context, it is important to have an awareness of what time zone each
+person is operating in and to communicate clearly around that.
+
+When looking at the output for `git log` on a distributed team, the timestamps
+for each entry can be all over the place. If I want to understand when something
+was committed, I have to look at the time as well as the time zone offset and
+mentally translate it to my own time zone.
+
+There is a `git config` option to alleviate this issue by having `git log`
+convert and display all timestamps into your local time zone.
+
+```bash
+$ git config --global log.date rfc-local
+```
+
+Running that will add this entry to your _global_ git config file:
+
+```
+[log]
+	date = rfc-local
+```
+
+Now the time that was displaying as `Wed Apr 8 20:12:33 2026 -0400` will display
+as `Wed, 8 Apr 2026 19:12:33 -0500`.
+
+This also helps with smoothing out differences from DST and for commits produced
+by AI agents in sandbox environments where the locale is set to UTC.
@@ -0,0 +1,33 @@
+# Programmatically Grab SHA For Head Commit
+
+When I use `gh browse path/to/some-file.txt`, it opens the browser to that file
+in GitHub. However, it targets the default branch (`main`) by default which is
+not very useful as a permalink because what that file looks like on `main` is
+liable to change.
+
+There is a `--commit` flag you can use to have it instead open to that file at a
+specific commit SHA.
+
+So what SHA do I pass as an argument to that flag?
+
+Often what I would like to grab is a reference to the current version of the
+file which is whatever it looks like for the `HEAD` commit. But `HEAD` is
+another moving target reference. The `git rev-parse` command can translate
+`HEAD` into a specific SHA though.
+
+```bash
+❯ git rev-parse --short HEAD
+3402428
+
+❯ git rev-parse HEAD
+3402428aadc02cfdc9825c8feb593443e72f50cd
+```
+
+Either of those will work. I can use a bash command substitution then to tie it
+all together into a single command:
+
+```bash
+❯ gh browse path/to/some-file.txt --commit=$(git rev-parse --short HEAD)
+```
+
+See `man git-rev-parse` for more details.
@@ -0,0 +1,31 @@
+# List PRs Awaiting Your Review
+
+If you work on a software team or steward an open-source project, then there are
+likely some open PRs that you've been tagged to review. I am usually able to
+catch most review requests as they come up either from the GitHub email
+notifications or by keeping an eye on the PRs tab of active projects. Sometimes
+I get consumed by a task and something slips through the cracks.
+
+There are a couple other ways to quickly check if anything is waiting on my
+review.
+
+From the web UI I can visit the following URL which will show all PRs across all
+projects where my review has been requested:
+
+[https://github.com/pulls/review-requested](https://github.com/pulls/review-requested)
+
+The GitHub CLI (`gh`) can do the same and I can do it right from the terminal
+instead of navigating several clicks within GitHub's web UI.
+
+```bash
+$ gh search prs --review-requested=@me --state=open
+```
+
+That too will list PRs across all projects that are open and awaiting my review.
+
+If that one ends up being a little too noisy, you can also use `gh` to _list_
+just PRs for the current project:
+
+```bash
+$ gh pr list --search "review-requested:@me"
+```
@@ -0,0 +1,46 @@
+# Open File To Specific Line In Browser
+
+Often one of the best ways to point a teammate to a line of code is to share a
+GitHub link to a specific file and line number. Sometimes even a specific
+commit.
+
+For the longest time I would manually open GitHub, navigate to that file, and so
+forth. The `gh` CLI supports this with the `browse` subcommand and it takes way
+less time if you already have the repo in your local filesystem.
+
+For instance, if I want to point you to line 11 of the `zshrc.local` file in my
+`dotfiles` repo, I can run the following command:
+
+```bash
+$ gh browse zshrc.local:11
+```
+
+That would open a browser tab to
+[https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11](https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11).
+
+If I wanted a range of lines, I could change it from `11` to, say, `11-27`:
+
+```bash
+$ gh browse zshrc.local:11-27
+```
+
+And I would see this in the browser --
+[https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11-L27](https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11-L27).
+
+Both of these URLs are pointing to the `main` branch. If I instead want to
+reference a specific commit, I can use the `--commit` flag.
+
+```bash
+$ gh browse zshrc.local:11-27 --commit=f2f9e78d4fc784643f725c88f7a5a7a077e7f261
+```
+
+I grabbed that from the latest commit in `git log`. That opens to
+[https://github.com/jbranchaud/dotfiles/blob/f2f9e78d4fc784643f725c88f7a5a7a077e7f261/zshrc.local?plain=1#L11-L27](https://github.com/jbranchaud/dotfiles/blob/f2f9e78d4fc784643f725c88f7a5a7a077e7f261/zshrc.local?plain=1#L11-L27).
+
+Another way of doing that would be to use `git rev-parse HEAD`:
+
+```bash
+$ gh browse zshrc.local:11-27 --commit=$(git rev-parse HEAD)
+```
+
+See `gh browse --help` for more details.
@@ -0,0 +1,58 @@
+# Process JSON Output From gh With jq
+
+The `gh` (GitHub) CLI is useful for accessing data about your profile and
+projects from the terminal. With the `--json` flag, we can access the data in a
+structured way which is useful for scripting.
+
+Here is an example of pulling a list of all my repositories, limiting each
+entity to just the `nameWithOwner` and `description`:
+
+```bash
+❯ gh repo list --limit 1000 --json nameWithOwner,description
+[
+  {
+    "description": "My personal site -- joshbranchaud.com",
+    "nameWithOwner": "jbranchaud/personal-site"
+  },
+  {
+    "description": "Private repo for the NOTES.md of my TIL repo",
+    "nameWithOwner": "jbranchaud/til-notes-private"
+  },
+  ...
+]
+```
+
+If I'm using the `--json` flag, then I can add in the `--jq` flag to apply a
+`jq` query for additional processing of the output.
+
+Here I convert it to a series of tuples:
+
+```bash
+❯ gh repo list --limit 1000 --json nameWithOwner,description \
+  --jq '.[] | [.nameWithOwner, .description]'
+[
+  "jbranchaud/personal-site",
+  "My personal site -- joshbranchaud.com"
+]
+[
+  "jbranchaud/til-notes-private",
+  "Private repo for the NOTES.md of my TIL repo"
+]
+...
+```
+
+Then I can add one more pipe to that `jq` query to turn it into _tab-separated
+values_ using
+[`@tsv`](https://jqlang.org/manual/v1.5/#format-strings-and-escaping):
+
+```bash
+❯ gh repo list --limit 1000 --json nameWithOwner,description \
+  --jq '.[] | [.nameWithOwner, .description] | @tsv'
+jbranchaud/personal-site	My personal site -- joshbranchaud.com
+jbranchaud/til-notes-private	Private repo for the NOTES.md of my TIL repo
+...
+```
+
+This is useful because I can then pipe it to another program, such as an `fzf`
+command like [this repo selector that opens the selected one in the
+browser](https://github.com/jbranchaud/dotfiles/commit/f964ca10c6c4db3475411c2991dc2f1dfd18c818).
@@ -0,0 +1,34 @@
+# Get User's Preferred Language From Browser
+
+A great way to determine a user's preferred language if you aren't able to ask
+them directly is to look at the language setting for their browser's UI.
+
+We can get this from the instance of
+[`Navigator`](https://developer.mozilla.org/en-US/docs/Web/API/Navigator) in the
+user's JavaScript runtime within the browser.
+
+My browser's UI is set to US English, which I can verify like so:
+
+```javascript
+> navigator.language
+'en-US'
+```
+
+This is useful for all sorts of things like [formatting dates for
+display](basic-date-formatting-without-a-library.md):
+
+```javascript
+> const now = new Date();
+> Intl.DateTimeFormat(navigator.language).format(now)
+'5/14/2026'
+```
+
+Or for [formatting other kinds of units for
+display](formatting-values-with-units-for-display.md):
+
+```javascript
+> const milesFormat =
+    Intl.NumberFormat(navigator.language, { style: "unit", unit: "mile" });
+> milesFormat.format(1500)
+"1,500 mi"
+```
@@ -0,0 +1,26 @@
+# Count Number Of Tokens In A File
+
+Over time you have accumulated a bunch of small directives, corrections, and
+project details in your `CLAUDE.md` or `AGENTS.md` file. The file doesn't seem
+too big, but you are mindful that it is being included in every prompt. How many
+tokens is it eating from the context window?
+
+OpenAI's BPE (Byte Pair Encoding) tokenization library,
+[`tiktoken`](https://github.com/openai/tiktoken), is an open-source Python
+package. If it is installed on our machine, then we can use it as part of the
+following one-liner to check a file:
+
+```bash
+❯ python -c "import tiktoken, sys; print(len(tiktoken.encoding_for_model('gpt-4o').encode(open(sys.argv[1], 'r', encoding='utf-8').read())))" \
+    AGENTS.md
+1018
+```
+
+I ran this against the `AGENTS.md` file in a team project I'm on. It came out to
+1018 tokens. This is a very good approximation based on the tokenizer trained
+for `gpt-4o`. The tokenizers may vary a little from model to model, but the
+differences for our purposes here are going to be negligible.
+
+This one-liner gets the "first" argument to the command, reads it in, and runs
+that string against the tokenizer. The length of the tokenized encoding is then
+printed.
@@ -0,0 +1,16 @@
+# Clean Up Item Layout In Finder Window
+
+Sometimes while doing a bunch of manual drag-n-drop of files and folders in a
+Finder.app window, I'll end up with a visual mess. Compared to other folders,
+nothing is organized on the grid.
+
+I can tell Finder.app to clean that up with the _Clean Up_ menu option.
+
+While focused on the folder that I'm concerned about, I can go to _View_ >
+_Clean Up_ in the top menu. Everything will snap into place.
+
+On the specific Finder.app window, there is also a triple-dot actions menu that
+appears on the top right. The _Clean Up_ action is available there as well.
+
+There is also a _Clean Up By_ option which is a nice way to organize by some
+attribute, such as the type (e.g Folder/File and extension).
@@ -0,0 +1,89 @@
+# Read The Lid Angle Sensor For A MacBook
+
+MacOS has a bunch of internal HID (Human Interface Device) data that can surface
+details about all kinds of "devices" that comprise your machine. Some obvious
+ones are the keyboard and trackpad as well as external mice and keyboards. The
+battery and power source details are another which is sometimes integrated into
+tools that display battery status (e.g.
+[`tmux-battery`](https://github.com/tmux-plugins/tmux-battery)), though it uses
+`pmset` directly). And many, many more.
+
+One example I'd never considered is that there is a sensor for the lid angle of
+the laptop that can tell the system whether the lid is open or closed and how
+open it is (i.e. at what angle). There is no public interface for this lid angle
+sensor, but people exploring all the HID devices have found the identifiers that
+correspond to it (e.g.
+[`pybooklid`](https://github.com/tcsenpai/pybooklid/blob/main/pybooklid/macbook_lid.py)).
+
+Here is a minimal script that uses `uv`, `hidapi` (python bindings), and
+`libhidapi` (shared runtime lib for those bindings):
+
+```python
+#!/usr/bin/env -S uv run --quiet --script
+# /// script
+# requires-python = ">=3.10"
+# dependencies = ["hidapi"]
+# ///
+"""Print MacBook lid angle in degrees."""
+import os, sys
+
+if sys.platform == "darwin":
+    brew = "/opt/homebrew/lib"
+    if os.path.exists(brew):
+        os.environ["DYLD_LIBRARY_PATH"] = f"{brew}:{os.environ.get('DYLD_LIBRARY_PATH','')}"
+
+import hid
+
+VENDOR_ID, PRODUCT_ID = 0x05AC, 0x8104
+USAGE_PAGE, USAGE = 0x0020, 0x008A
+REPORT_ID = 1
+
+def read_angle():
+    for info in hid.enumerate(VENDOR_ID, PRODUCT_ID):
+        if info.get("usage_page") == USAGE_PAGE and info.get("usage") == USAGE:
+            d = hid.device()
+            path = info["path"]
+            d.open_path(path if isinstance(path, bytes) else path.encode())
+            try:
+                data = d.get_feature_report(REPORT_ID, 8)
+                if data and len(data) >= 3:
+                    return float((data[2] << 8) | data[1])
+            finally:
+                d.close()
+    return None
+
+if __name__ == "__main__":
+    a = read_angle()
+    if a is None:
+        sys.exit("sensor not available")
+    print(f"{a:.0f}")
+```
+
+These IDs and usage values are the undocumented values that allow the script to
+navigate specifically to the lid angle sensor and specifically to the usage page
+and value that represent the current lid angle reading.
+
+```
+VENDOR_ID, PRODUCT_ID = 0x05AC, 0x8104
+USAGE_PAGE, USAGE = 0x0020, 0x008A
+REPORT_ID = 1
+```
+
+I added [this
+script](https://github.com/jbranchaud/dotfiles/blob/cbc7196607d1d6b25885f5387ca85b658bd765de/bin/lidangle)
+to [my dotfiles](https://github.com/jbranchaud/dotfiles) and made it executable
+(`chmod +x bin/lidangle`) so that I can try it out. I first ran it while it was
+closed and connected to my external monitor (`0`), then I opened it as far as it
+could go (`129`), and then I tried angling it close to what I thought was 90
+degress (`92`, so close).
+
+```bash
+❯ lidangle
+0
+
+❯ lidangle
+129
+
+❯ lidangle
+92
+```
@@ -0,0 +1,20 @@
+# Reveal Location Of File In Finder.app
+
+In the terminal I have the path to an image file. I want to open Finder.app to
+the location of that image file so that I can drag and drop it into a file
+upload area in the browser.
+
+Instead of opening a Finder.app window and navigating directory by directory to
+the location, I can use the `open` command. Using `open` directly with the image
+file will open the image in Preview.app. I want to reveal the directory that the
+image file is in within Finder.app. _Reveal_ is the keyword and the `-R` flag
+does just that.
+
+Here is an example of this that I actually ran when uploading a screenshot that
+went into [this blogmark post](https://still.visualmode.dev/blogmarks/255):
+
+```bash
+$ open -R /Users/lastword/images/tiobe-index-graph-march-2026.png
+```
+
+See `man open` for more details.
@@ -0,0 +1,42 @@
+# Generate Permutations Of All Valid 9-ball Racks
+
+I wanted to produce a full listing of all valid rack arrangements for the game
+of [9-ball](https://en.wikipedia.org/wiki/Nine-ball). The constraints on how a
+9-ball rack can be arranged are, first, that the 1 ball must be placed at the
+head of the diamond and, second, that the 9 ball must be placed at the center of
+the diamond. After that, all other balls (2 through 8) can be placed in any
+arrangement.
+
+Because each of those seven remaining balls can be arranged in distinct
+orderings where each ball is placed once, this is a
+[_permutation_](https://en.wikipedia.org/wiki/Permutation) problem.
+
+> In elementary combinatorics, the k-permutations, or partial permutations, are
+> the ordered arrangements of k distinct elements selected from a set. When k is
+> equal to the size of the set, these are the permutations in the previous
+> sense.
+
+For this problem, the seven distinct elements can be arranged into `7!` (seven
+factorial) unique permutations. That is, 5040 permutations.
+
+I can use [Ruby's `Array#permutations`
+method](https://docs.ruby-lang.org/en/4.0/Array.html#method-i-permutation) to
+enumerate these 5040 permutations like so:
+
+```ruby
+[2,3,4,5,6,7,8].permutation.map do |perm|
+  [1, *perm[0..2], 9, *perm[3..7]]
+end.to_a
+=> [[1, 2, 3, 4, 9, 5, 6, 7, 8],
+ [1, 2, 3, 4, 9, 5, 6, 8, 7],
+ [1, 2, 3, 4, 9, 5, 7, 6, 8],
+ [1, 2, 3, 4, 9, 5, 7, 8, 6],
+ [1, 2, 3, 4, 9, 5, 8, 6, 7],
+ [1, 2, 3, 4, 9, 5, 8, 7, 6],
+ [1, 2, 3, 4, 9, 6, 5, 7, 8],
+ ...
+ [1, 8, 7, 6, 9, 5, 3, 2, 4],
+ [1, 8, 7, 6, 9, 5, 3, 4, 2],
+ [1, 8, 7, 6, 9, 5, 4, 2, 3],
+ [1, 8, 7, 6, 9, 5, 4, 3, 2]]
+```
@@ -0,0 +1,29 @@
+# Avoid Vulnerabilities In New Package Versions
+
+It seems like every week there is a new supply chain attack where malicious code
+is embedded in a popular, widely-used OSS package. This week's is
+[axios](https://www.stepsecurity.io/blog/axios-compromised-on-npm-malicious-versions-drop-remote-access-trojan).
+
+The [`pnpm` package manager](https://pnpm.io/) has a nice feature that helps
+avoid installing these vulnerable package versions in the first place.
+
+> To reduce the risk of installing compromised packages, you can delay the
+> installation of newly published versions. In most cases, malicious releases
+> are discovered and removed from the registry within an hour.
+
+The [`minimumReleaseAge` config option](https://pnpm.io/settings#minimumreleaseage) tells `pnpm` to not install
+a dependency (including transitive ones) until it has been released for at least
+that many minutes.
+
+For instance, if you wanted to set this to 72 hours, then you'd set this option
+to `4320` minutes like so:
+
+```
+$ pnpm config set minimum-release-age 4320 -g
+```
+
+The global flag (`-g`) will set that in your global config location, e.g.
+`$XDG_CONFIG_HOME/pnpm/rc`. You could also add it specifically to your project
+in the `pnpm-workspace.yaml` file.
+
+[source](https://bsky.app/profile/styfle.dev/post/3miekuyeyrs2w)
@@ -0,0 +1,44 @@
+# Access Variables Outside Loop Scope
+
+Here is a function that loops over a list to find the first occurrence of a
+falsy value.
+
+```python
+def find_false(self):
+    for item in self.items:
+        item_type = type(item)
+        print(f"Current item: {item} ({item_type})")
+        if not item:
+            break
+
+    print(f"First false item: {item} ({item_type})")
+```
+
+Notice how at the end of the function, outside of the loop, I am able to access
+both `item` (defined in the loop definition) and `item_type` (defined within the
+loop's body).
+
+Both of these variables are defined, by the loop, in _function scope_ and are
+accessible anywhere in the function after they have been defined.
+
+The title of this TIL is a bit of a misnomer because Python doesn't have the
+concept of a _loop scope_. There are two levels of scope in Python --
+module/global scope and function scope.
+
+I spend most of my time writing Ruby which also has _block scope_, so Python's
+simplified two-level scoping took me by surprise.
+
+Though the code sample above is contrived, this function scope assignment can be
+taken advantage of with loop definitions in scenarios where you want to know
+what the last `item` defined was before the loop terminated.
+
+```python
+for submission in submissions:
+    if passes(submission, criteria):
+        break
+else:
+    raise ValueError("No submissions that meet given criteria")
+
+print(f"Submit first passing submission: {submission.id}")
+submit(submission)
+```
@@ -0,0 +1,76 @@
+# Argument Defaults Are Evaluated When Function Is Defined
+
+When you define a function with any arguments that have default values, those
+default values are evaluated and stored at the time that the function is defined
+(i.e. when it is evaluated by the interpreter). This might feel counter
+intuitive if you are coming from another language, like Ruby, where these kinds
+of defaults are evaluated at call time. This is unremarkable for scalar values
+like `4` or `"fallback"`. It's much more interesting when your defaults are
+function calls.
+
+What if our default is something like `datetime.now()`?
+
+Here I've defined a `Timer` class that has a `start` and `stop` method. The
+`stop` method can be called with a specific `datetime` value otherwise it falls
+back to `datetime.now()` -- but when is _now_?
+
+```python
+from datetime import datetime, timezone
+import time
+
+
+class Timer:
+    def __init__(self):
+        self._start = None
+        self._stop = None
+
+    def start(self):
+        self._start = datetime.now(timezone.utc)
+        self._stop = None
+
+    def stop(self, at=datetime.now(timezone.utc)):
+        print(f"now: {datetime.now(timezone.utc)}")
+        print(f" at: {at}")
+        self._stop = at
+
+        elapsed = self._stop - self._start
+        return elapsed
+```
+
+Here I instantiate a timer, call `start`, sleep for 5 seconds, and then call
+`stop`.
+
+```python
+timer = Timer()
+timer.start()
+
+time.sleep(5)
+
+print(f"Elapsed: {timer.stop()}")
+```
+
+Here is what gets printed to `stdout`:
+
+```
+now: 2026-05-22 00:45:05.654878+00:00
+ at: 2026-05-22 00:45:00.649699+00:00
+Elapsed: -1 day, 23:59:59.999875
+```
+
+Notice that the actual _now_ (when the `stop` method is running) is about 5
+seconds after the value of `at`. That is because `at`, which takes on the
+default argument value, is `datetime.now()` as evaluated at the time the
+function is interpreted. It is for that same reason that `self._stop` ends up
+being just a hair earlier than the call to `start` which sets `self._start`.
+Which explains why the _elapsed_ time is a negative value.
+
+To avoid this awkwardness all together, set the default as `None` and then
+override `None` at the start of the function:
+
+```python
+def stop(self, at = None):
+    if at == None:
+        at = datetime.now(timezone.utc)
+
+    # ...
+```
@@ -0,0 +1,38 @@
+# Assert Is Only A Development Check
+
+The `assert` keyword is used in Python to write a statement that will check some
+assertion and raise an error if it isn't met. This is only meant to be used as a
+check during development because it can be easily optimized out of the code.
+
+```python
+stuff = None
+
+assert stuff, "We need to have some stuff to proceed"
+
+print(f"We have {stuff or 'something'}!")
+```
+
+If I execute this code with `python`, it will raise on that second line of code.
+
+```bash
+❯ python assert_example.py
+Traceback (most recent call last):
+  File "/Users/lastword/dev/jbranchaud/py-vmt/assert_example.py", line 3, in <module>
+    assert stuff, "We need to have some stuff to proceed"
+           ^^^^^
+AssertionError: We need to have some stuff to proceed
+```
+
+This `assert` statement will be stripped out of the compiled bytecode if the
+`-O` (capital o) flag is used. Notice how running the same file with that flag
+does not lead to an `AssertionError`.
+
+```python
+❯ python -O assert_example.py
+We have something!
+```
+
+If I want to make sanity checks for situations that would be caused by a bug in
+the code, an `assert` statement can be a good candidate. However, if I am making
+runtime checks like validating user input, then an `if` statement and raising
+something like a `ValueError` is better.
@@ -0,0 +1,47 @@
+# Avoid Modification With Frozen Dataclass
+
+The `@dataclass` decorator can be set as _frozen_ to prevent modification of
+values on instances of that `dataclass`.
+
+Without making it frozen, I can easily subvert validations by changing the value
+of attributes after the `__post_init__` validations are called.
+
+```python
+>>> config = BPEConfig(300, []) # passes validations
+>>> config.vocab_size = 22 # this is invalid, wish this was prevented
+```
+
+Here is the updated `@dataclass` declaration with `frozen=True` passed as a
+parameter.
+
+```python
+from dataclasses import dataclass
+from typing import ClassVar
+
+@dataclass(frozen=True)
+class BPEConfig:
+    BASE_VOCAB_SIZE: ClassVar[int] = 256
+
+    vocab_size: int
+    special_tokens: list[str]
+
+    def __post_init__(self):
+        if self.vocab_size < self.BASE_VOCAB_SIZE:
+            msg = f"vocab_size ({self.vocab_size}) must be greater than or equal to BASE_VOCAB_SIZE ({self.BASE_VOCAB_SIZE})"
+            raise ValueError(msg)
+```
+
+Now I am prevented from modifying a scalar value like `vocab_size` after the
+instance has been created.
+
+```python
+>>> config = BPEConfig(300, [])
+>>> config.vocab_size = 22
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+  File "<string>", line 4, in __setattr__
+dataclasses.FrozenInstanceError: cannot assign to field 'vocab_size'
+```
+
+This doesn't prevent you from modifying the contents of attributes that are
+`list` or `dict` types.
@@ -0,0 +1,53 @@
+# Check Precondition Before Click Arg Parsing
+
+When setting up various [Click](https://click.palletsprojects.com/en/stable/)
+subcommands with options, I ran into an issue with the order of some validation
+checks. I was putting the same precondition validation logic at the beginning of
+several subcommands. I was also putting callback validations on specific options
+to those subcommands. Ideally the option validations could rely on those
+precondition validations. However, the option callbacks run before anything in
+the body of the subcommands.
+
+The solution was to move those preconditions out of the subcommand body
+(simplifying the subcommand) and into a `click.Command` subclass.
+
+To demonstrate that, I'll first show the `click.Command` subclass:
+
+```python
+class RequireActiveSessionCommand(click.Command):
+    def parse_args(self, ctx, args):
+        if ctx.obj.active_session is None:
+            msg = "No active session being tracked. Start a session first."
+            raise click.UsageError(msg)
+
+        return super().parse_args(ctx, args)
+```
+
+The only thing this subclass overrides is `parse_args` where it gets ahead of
+the standard arg parsing logic to first check the precondition. In this case, I
+check that there is an active session. If there isn't, then I can raise a
+`click.UsageError`. Otherwise, it delegates back to the super-class
+implementation of `parse_args`.
+
+This subclass then gets used for the commands that need to enforce this
+precondition. Two prime examples of that are the `stop` and `cancel` subcommands.
+
+```python
+@cli.command(cls=RequireActiveSessionCommand)
+@click.option("--at", help='Hours previous to end the timer, e.g. "2 hours ago"', callback=validate_stop_at)
+@pass_cli
+def stop(cli_ctx: CliContext, at: datetime) -> None:
+    # ... implementation omitted
+
+@cli.command(cls=RequireActiveSessionCommand)
+@pass_cli
+def cancel(cli_ctx: CliContext):
+    # ... implementation omitted
+```
+
+Other subcommands, like `start` and `status` that don't need to enforce this
+precondition use the `@cli.command()` decorator without passing in a custom
+subclass.
+
+This example is pulled directly from [this commit](https://github.com/jbranchaud/py-vmt/commit/505109b7a4013e05f085cded666c6b1ac7c3c250)
+of my [`py-vmt` time tracker tool](https://github.com/jbranchaud/py-vmt).
@@ -0,0 +1,40 @@
+# Control Passing Of Time In Tests
+
+While it is nice to be able to write pure functional code, our software still
+lives in the real world and may have to relate to or depend on the passing of
+time. In order to test this kind of code, we need time to behave in a reliable,
+deterministic way. One of the best ways to create a testing environment where
+that is true is to bring in tooling that hijacks time.
+
+The [`freezegun` module](https://github.com/spulec/freezegun) is a great tool
+for that job. We can use it to freeze time at a specific testable point, advance
+time a specific amount, and much more.
+
+Here is an example from the tests for [my CLI-based time tracking
+app](https://github.com/jbranchaud/py-vmt/blob/acb26e4840279d936a12f16c505ca7e75e9a6d20/tests/src/py_vmt/test_cli.py#L21)
+where I freeze time before starting a session. That gives me a chance to assert
+about the exact start time that is output by the command. Then I can advance
+time a little and assert that the `status` command outputs the correct thing.
+
+```python
+import datetime
+from freezegun import freeze_time
+
+# some other test setup omitted ...
+
+initial_datetime = datetime.datetime(
+    2026, 3, 14, 15, 5, 11, 0, datetime.timezone.utc
+)
+with freeze_time(initial_datetime) as frozen_datetime:
+    # start a session
+    start_result = runner.invoke(cli, ["start", "my-project"])
+    output = "Started tracking 'my-project' at 10:05AM"
+    assert output in start_result.output
+
+    frozen_datetime.tick(delta=datetime.timedelta(minutes=30))
+
+    # check status
+    status_result = runner.invoke(cli, ["status"])
+    output = "Tracking 'my-project' for 30m (since 10:05AM)"
+    assert output in status_result.output
+```
@@ -0,0 +1,44 @@
+# Create A Range Of Descending Values
+
+A typical use of `range` looks something like this:
+
+```python
+>>> list(range(1, 5))
+[1, 2, 3, 4]
+```
+
+Which is equivalent to this one where we give a `step` value of `1`.
+
+```python
+>>> list(range(1, 5, 1))
+[1, 2, 3, 4]
+```
+
+If we try to create a _negative range_, that is, a range of values in decreasing
+order, we get an empty list.
+
+```python
+>>> list(range(0, -7))
+[]
+```
+
+That's because the `step` value still defaults to `1`. And there are no positive
+steps between `0` and `-7`. So, let's give `range` a `step` value of `-1`.
+
+```python
+>>> list(range(0,-7, -1))
+[0, -1, -2, -3, -4, -5, -6]
+```
+
+One practical use case of a negative range like this is using a list
+comprehension to transform it into a list of the _last seven days_.
+
+```python
+>>> from datetime import datetime, timedelta
+>>> [datetime.now().date() + timedelta(days=days) for days in range(0,-7, -1)]
+[datetime.date(2026, 3, 19), datetime.date(2026, 3, 18), datetime.date(2026, 3, 17), datetime.date(2026, 3, 16), datetime.date(2026, 3, 15), datetime.date(2026, 3, 14), datetime.date(2026, 3, 13)]
+```
+
+Of course this could have been written with a positive range and then
+subtracting the `timedelta`. I like that I have the option of doing this in
+whatever way makes the code most readable.
@@ -0,0 +1,46 @@
+# Deduplicate A List Into A Tuple
+
+A `list` is not hashable which means you can't use it for things like `dict`
+keys or cache keys. Instead you need to convert it into something like a `set`
+or a `tuple`.
+
+Here is an example list:
+
+```python
+>>> l1 = [3,4,1,2,5,4,1]
+```
+
+Turning this list into a `set` or `frozenset` is straightforward:
+
+```python
+>>> set(l1)
+{1, 2, 3, 4, 5}
+>>> frozenset(l1)
+frozenset({1, 2, 3, 4, 5})
+```
+
+If you're trying to preserve the order after deduplicating, then you'll want to
+use a `tuple` instead of a `set`. In order to deduplicate while maintaining the
+ordering, you can exploit the fact that `dict` keys maintain their order. A
+`list` can be transformed into the keys of a `dict` with
+[`dict.fromkeys`](https://docs.python.org/3/library/stdtypes.html#dict.fromkeys):
+
+```python
+>>> dict.fromkeys(l1)
+{3: None, 4: None, 1: None, 2: None, 5: None}
+```
+
+And here is your `tuple` which extracts the keys of the `dict`:
+
+```python
+>>> tuple(dict.fromkeys(l1))
+(3, 4, 1, 2, 5)
+```
+
+By comparison, here is the `tuple` transformed directly from the `list` without
+deduplication.
+
+```python
+>>> tuple(l1)
+(3, 4, 1, 2, 5, 4, 1)
+```
@@ -0,0 +1,60 @@
+# Define Sequence Of Tests With Parametrize Decorator
+
+I have a function that I want to test across a bunch of different inputs. That
+way I can make sure the logic of that function handles all the different
+scenarios I have in mind.
+
+While working on [`py-vmt`](https://github.com/jbranchaud/py-vmt), I started by
+writing a big single test function with a sequence of variable assignments and
+`assert` statements. Here's my starting point:
+
+```python
+def test_format_time_delta_everything():
+    # less than a minute
+    thirty_seconds = timedelta(seconds=30)
+    assert "30s" == format_time_delta(thirty_seconds)
+
+    # one minute exactly
+    one_minute = timedelta(seconds=60)
+    assert "1m" == format_time_delta(one_minute)
+
+    # more than a minute
+    assert "1m30s" == format_time_delta(one_minute + thirty_seconds)
+
+    # bunch of minutes and seconds
+    delta = timedelta(minutes=24, seconds=8)
+    assert "24m8s" == format_time_delta(delta)
+
+    # one hour exactly
+    one_hour = timedelta(hours=1)
+    assert "1h" == format_time_delta(one_hour)
+
+    # more than one hour
+    assert "1h24m" == format_time_delta(one_hour + delta)
+```
+
+I knew I would eventually need to break it up into individual test functions,
+but I couldn't bare to start there because it seemed quite repetitive.
+
+There is another way to approach this without all the duplication. Pytest comes
+with [a "parametrize" decorator](https://docs.pytest.org/en/stable/example/parametrize.html). This is
+used to define a set of test data (and expected values) that will get passed
+one-by-one to the test function as parameters.
+
+```python
+@pytest.mark.parametrize("input,expected", [
+    (timedelta(seconds=30), "30s"),
+    (timedelta(seconds=60), "1m"),
+    (timedelta(seconds=90), "1m30s"),
+    (timedelta(minutes=24, seconds=8), "24m8s"),
+    (timedelta(hours=1), "1h"),
+    (timedelta(hours=1, minutes=24, seconds=8), "1h24m"),
+])
+def test_format_time_delta(input, expected):
+    assert format_time_delta(input) == expected
+```
+
+I ditch all of the duplication this way. I define a list of tuples that
+represent my input values and expected values. Then the body of the test can be
+minimal. And I get a separate test execution for each parameter tuple making it
+easier to see fine-grained pass/fail results.
@@ -0,0 +1,42 @@
+# Define Typed Class Interface With Protocol
+
+In [`py-vmt`](https://github.com/jbranchaud/py-vmt) I am defining different
+storage access layers for the CLI to use. I want a consistent interface that the
+core CLI logic can depend on regardless of whether it is a JSON file or a SQLite
+database. To achieve that I can define a class of unimplemented functions that
+inherits from
+[`typing.Protocol`](https://typing.python.org/en/latest/spec/protocol.html).
+
+```python
+from typing import Protocol
+
+class SessionRepository(Protocol):
+    def active_session(self) -> Session | None: ...
+    def write_active_session(self, session) -> None: ...
+    def append_session(self, session) -> None: ...
+    def all_sessions(self) -> list[Session]: ...
+    def clear_active_session(self) -> None: ...
+```
+
+Notice that none of these have default implementations. The `...` indicates that
+class implementing this protocol will define the implementation of those
+functions.
+
+Now, my `CliContext` class, which needs some kind of `SessionRepository` to
+function can indicate as much in `__init__`.
+
+```python
+class CliContext:
+    def __init__(self, verbose: bool, repo: SessionRepository | None = None) -> None:
+        self.verbose: bool = verbose
+        self.active_session: Session | None = None
+        self.repo: SessionRepository = repo or JsonRepository()
+        self.active_session = self.repo.active_session()
+```
+
+If `JsonRepository` doesn't define all of the methods specified in the protocol,
+then a type error will occur wherever it clashes with `SessionRepository`. Now
+as I implement `SqliteRepository` I have a standard interface to build against
+that I know I can seamlessly swap in.
+
+[source](https://typing.python.org/en/latest/reference/protocols.html#simple-user-defined-protocols)
@@ -0,0 +1,24 @@
+# Enable Pyright Type Checking In Cursor
+
+In most ways [Cursor](https://cursor.com/), a clone of VS Code, behaves like VS
+Code and uses the same extensions as VS Code. It even offers to clone all your
+existing extensions and setup from VS Code when you first install it.
+
+However, the Pyright type checking setup that I had in VS Code stopped working
+when I opened up the same Python project in Cursor. It seems that to get Pyright
+to reliably work with forks of VS Code, you need to use a compatible fork like
+[Based Pyright](https://docs.basedpyright.com/latest/).
+
+Once I installed _Based Pyright_ from the extension marketplace, I was able to
+enable it in `.vscode/settings.json`:
+
+```json
+{
+    ...,
+    "basedpyright.analysis.typeCheckingMode": "basic"
+}
+```
+
+I may have needed to restart Cursor at this point, I cannot remember exactly.
+However, once this setup was in place the helpful type checking errors started
+appearing as red squiggles.
@@ -0,0 +1,64 @@
+# Get Absolute Seconds From `timedelta` Object
+
+The [`timedelta` object provided by
+`datetime`](https://docs.python.org/3/library/datetime.html#timedelta-objects)
+is a useful built-in concept for representing a duration of time.
+
+```python
+>>> from datetime import timedelta
+>>> diff = timedelta(hours=1, minutes=1, seconds=6)
+>>> diff.seconds
+3666
+```
+
+It is pretty minimal though. There are only a couple things you can inspect
+about it -- `days`, `seconds` (as I did in the snippet above), and
+`microseconds`.
+
+And perhaps that is enough to hint at the issue I recently ran into with it --
+specifically that you can access both `days` and `seconds`.
+
+Let's look at what happens when I have a `timedelta` with more than a day worth
+of seconds.
+
+```python
+>>> diff = timedelta(seconds=(3600 * 24 + 1))
+>>> diff.seconds
+1
+>>> diff.days
+1
+```
+
+I thought `seconds` was going to produce `86401` instead of `1`. The reason is
+because any amount of duration over a day gets converted into the `days` value
+and its the remaining time smaller than a day that is represented by `seconds`.
+
+In my [original implementation of
+`format_time_delta`](https://github.com/jbranchaud/py-vmt/blob/c14eaa56cf5f5c6d0120a95f04f95a6c87443e1c/src/py_vmt/time_helpers.py#L11-L14),
+I was trying to build a relative time string by converting `seconds` into hours,
+minutes, and seconds. That approach falls apart as soon as the delta is greater
+than a day.
+
+```python
+def format_time_delta(diff) -> str:
+    hours, remainder = divmod(diff.seconds, 3600)
+    minutes, remainder = divmod(remainder, 60)
+    seconds = remainder
+
+    # ...
+```
+
+Instead, I needed to reach for [the `total_seconds()` function](https://docs.python.org/3/library/datetime.html#datetime.timedelta.total_seconds).
+This gives "the total number of seconds contained in the duration" and is
+described as equivalent to `diff / timedelta(seconds=1)`.
+
+Here is the [updated version of `format_time_delta`](https://github.com/jbranchaud/py-vmt/blob/ec1875a9d73552f5481e3945ddf522e94d0cc018/src/py_vmt/time_helpers.py?plain=1#L11-L16):
+
+```python
+def format_time_delta(diff: timedelta) -> str:
+    total_seconds = int(diff.total_seconds())
+
+    hours, remainder = divmod(total_seconds, 3600)
+    minutes, remainder = divmod(remainder, 60)
+    seconds = remainder
+```
@@ -0,0 +1,42 @@
+# Get Quotient And Remainder In One Operation
+
+While writing some custom code to transform a number of seconds into the
+constituent hours, minutes, and seconds, I found myself needing to get both the
+quotient and remainder from a division between two numbers.
+
+```python
+>>> import math
+>>> math.floor(3666 / 3600)
+1
+>>> 3666 % 3600
+66
+```
+
+Instead, I can use Python's built-in
+[`divmod`](https://docs.python.org/3/library/functions.html#divmod) function to
+compute both values in one statement.
+
+```python
+>>> divmod(3666, 3600)
+(1, 66)
+```
+
+The result is a tuple with the first value being my quotient (in this case, the
+number of hours) and the remainder (the remaining number of seconds).
+
+This kind of operation is known as [Euclidian
+Division](https://en.wikipedia.org/wiki/Euclidean_division).
+
+Here is a snippet of some actual code where I use this in
+[`py-vmt`](https://github.com/jbranchaud/py-vmt/blob/b9eae8b258e9fd720cfa3bb63b601225df352051/src/py_vmt/time_helpers.py#L14-L16):
+
+```python
+def format_time_delta(diff: timedelta) -> str:
+    total_seconds = int(diff.total_seconds())
+
+    hours, remainder = divmod(total_seconds, 3600)
+    minutes, remainder = divmod(remainder, 60)
+    seconds = remainder
+
+    # ...
+```
@@ -0,0 +1,41 @@
+# Look Inside Pytest tmp_path
+
+In [Isolate and Debug File Side-Effects with Pytest
+`tmp_path`](https://www.visualmode.dev/isolate-and-debug-file-side-effects-with-pytest-tmp-path),
+I wrote about how I use
+[`tmp_path`](https://docs.pytest.org/en/stable/reference/reference.html#std-fixture-tmp_path)
+in a Pytest fixture to test [my `py-vmt` CLI](https://github.com/jbranchaud/py-vmt). During testing of the CLI interface
+via [`click`'s testing utilities](https://click.palletsprojects.com/en/stable/testing/), `vmt` creates,
+modifies, and reads from files. Isolating that behavior with the `tmp_path`
+fixture is useful because it prevents individual test cases from conflicting
+with one another.
+
+Here is what the fixture looks like at the top of my test file:
+
+```python
+# auto fixture for all test cases that monkeypatches the platform dirs to a tmp
+# path so that test side-effects don't persist between runs
+@pytest.fixture(autouse=True)
+def use_tmp_platform_dirs(tmp_path, monkeypatch):
+    data_dir = tmp_path / "data"
+    config_dir = tmp_path / "config"
+    data_dir.mkdir()
+    config_dir.mkdir()
+    monkeypatch.setattr(CliContext, "get_data_dir", staticmethod(lambda: data_dir))
+    monkeypatch.setattr(CliContext, "get_config_dir", staticmethod(lambda: config_dir))
+```
+
+The root of the temp directory is located at `tempfile.gettempdir()` and the
+directories from there are organized with this structure:
+
+```
+{temproot}/pytest-of-{user}/pytest-{num}/{testname}/
+```
+
+So, in the case of `vmt`, I can find the `config` and `data` dirs for a specific
+test run here:
+
+```bash
+❯ ls /var/folders/zc/q6gnvbgx6kq77828jn38716r0000gn/T/pytest-of-lastword/pytest-2/test_start_status_stop_flow0
+config data
+```
@@ -0,0 +1,45 @@
+# Make Dataclass Sortable By Specific Field
+
+One way to sort a list of some `dataclass` is to define the `key` parameter when
+calling `sort` or `sorted` like I discussed in [Sort a List of Dataclass
+Instances](sort-a-list-of-dataclass-instances.md):
+
+```python
+for date in sessions_grouped_by_day.keys():
+    sessions_grouped_by_day[date].sort(
+        key=lambda session: session.start_time.time()
+    )
+```
+
+But then that lambda for `key` needs to be defined everywhere you sort.
+
+If the dataclass has a single, specific field that acts as a natural proxy for
+sort order, then you can define that in the `dataclass` implementation with the
+`__lt__` method.
+
+As long as a class defines the _less than_ dunder method, it will be sortable.
+
+Here is what that looks like for this `Session` dataclass:
+
+```python
+from dataclasses import dataclass
+from datetime import datetime, timezone
+
+@dataclass
+class Session:
+    start_time: datetime
+    project_name: str
+    end_time: datetime | None = None
+
+    def __lt__(self, other):
+        if not isinstance(other, Session):
+            return NotImplemented
+        return self.start_time < other.start_time
+
+    # more methods below ...
+```
+
+This implementation of `__lt__` tells the sorting methods that _this_ (`self`)
+instance of `Session` can be compared to some `other` instance of `Session` by
+comparing their `start_time` values to see which is less than. The guard at the
+beginning makes sure only instances of `Session` are being compared.
@@ -0,0 +1,48 @@
+# Make Secure Temp File For Atomic Write
+
+Two types of failure modes that can occur while writing to a shared file on the
+file system are 1) a corrupted file due to a crash mid-write and 2) another
+process reading a partial file mid-write.
+
+One way I've handled this in [`py-vmt`](https://github.com/jbranchaud/py-vmt) is
+to perform the write operations on a secure temp file and then use the OS-level
+atomic `rename` operation. I do this by [creating a
+`contextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager)
+that uses
+[`tempfile.mkstemp`](https://docs.python.org/3/library/tempfile.html#tempfile.mkstemp)
+and [`os.replace`](https://docs.python.org/3/library/os.html#os.replace).
+
+Here is what the `contextmanager` looks like:
+
+```python
+from contextlib import contextmanager
+from pathlib import Path
+import os, tempfile
+
+@contextmanager
+def atomic_write(path: Path):
+    # write to a tmp file in the same directory, then atomically swap it
+    fd, temp_file_path = tempfile.mkstemp(dir=path.parent, suffix=".tmp")
+    try:
+        with os.fdopen(fd, "w") as file:
+            yield file
+        os.replace(temp_file_path, path)
+    except BaseException:
+        os.unlink(temp_file_path)
+        raise
+```
+
+This explicitly creates a secure temp file in the same directory as the given
+path with `.tmp` as the suffix. I then open the file descriptor using the
+`os.fdopen` context manager (which will manage closing the file descriptor for
+me). The `@contextmanager` decorator plus the `yield file` are what allow this
+to be used as a `with` block. Once any file operations are done, then I use
+`os.replace` to atomically swap out the original file with the temp file.
+
+Here is how I use it to write updates to JSON data files:
+
+```python
+def write_active_session(self, session: Session) -> None:
+    with atomic_write(self.active_session_file) as file:
+        json.dump(session.marshal(), file)
+```
@@ -0,0 +1,76 @@
+# Reclassify Certain Packages As Dev Dependencies
+
+When I first started working on [py-vmt](https://github.com/jbranchaud/py-vmt),
+I wasn't differentiating certain test packages as _dev_ dependencies as opposed
+to standard, production dependencies. This can lead to bloated installs across a
+variety of distribution channels.
+
+Notice that I have everything treated as production dependencies:
+
+```bash
+❯ uv tree --no-dev
+Resolved 18 packages in 2ms
+py-vmt v0.1.0
+├── click v8.3.1
+├── dateparser v1.3.0
+│   ├── python-dateutil v2.9.0.post0
+│   │   └── six v1.17.0
+│   ├── pytz v2026.1.post1
+│   ├── regex v2026.2.28
+│   └── tzlocal v5.3.1
+├── freezegun v1.5.5
+│   └── python-dateutil v2.9.0.post0 (*)
+├── platformdirs v4.9.4
+├── pytest v9.0.2
+│   ├── iniconfig v2.3.0
+│   ├── packaging v26.0
+│   ├── pluggy v1.6.0
+│   └── pygments v2.19.2
+└── types-dateparser v1.3.0.20260211
+(*) Package tree already displayed
+```
+
+`pytest`, `freezegun`, and `types-dateparser` are better suited as _dev_
+dependencies.
+
+I can reclassify them by moving them from `dependencies` into a `dev` dependency
+group in `pyproject.toml`:
+
+```toml
+dependencies = ["click>=8.3.1", "dateparser>=1.3.0", "platformdirs>=4.9.4"]
+[dependency-groups]
+dev = ["freezegun>=1.5.5", "pytest>=9.0.2", "types-dateparser>=1.3.0.20260211"]
+```
+
+I only had `dependencies` before, so I had to add `[dependency-groups]` and `dev = []` to my `pyproject.toml` file.
+
+I can then tell `uv` to sync up the installation and virtualenv based on the new
+organization of the dependencies.
+
+```bash
+❯ uv sync
+warning: Skipping installation of entry points (`project.scripts`) because this project is not packaged; to install entry points, set `tool.uv.package = true` or define a `build-system`
+Resolved 18 packages in 518ms
+```
+
+Now when I check the `--no-dev` tree of dependencies, it's just the essentials:
+
+```bash
+❯ uv tree --no-dev
+Resolved 18 packages in 1ms
+py-vmt v0.1.0
+├── click v8.3.1
+├── dateparser v1.3.0
+│   ├── python-dateutil v2.9.0.post0
+│   │   └── six v1.17.0
+│   ├── pytz v2026.1.post1
+│   ├── regex v2026.2.28
+│   └── tzlocal v5.3.1
+└── platformdirs v4.9.
+```
+
+Another way to achieve this would have been to run `uv remove` and `uv add` with
+the relevant sets of package names. In retrospect, I would have preferred using
+that approach in the first place. If you're wanting to be pinned to specific
+versions of certain packages, you'd have to be a little more careful to get this
+right.
@@ -0,0 +1,62 @@
+# Set Up Pyright Type Checking In GitHub
+
+As I get into more of a PR workflow with my development of
+[`py-vmt`](https://github.com/jbranchaud/py-vmt), I need to set up some basic CI
+checks in GitHub. For starters I want the same `pyright` type checking that I
+have locally to be run in CI for consistency.
+
+Though my editor is set up to do Pyright type checking as I work locally, I can
+also manually run it with:
+
+```bash
+$ uv run pyright
+```
+
+Pyright will look for the `tool.pyright` section in my `pyproject.toml` file
+which currently looks like the following:
+
+```toml
+[tool.pyright]
+include = ["src", "tests"]
+```
+
+I can get this same type checking in CI for PRs by adding the following
+`.github/workflows/typecheck.yml` file:
+
+```yaml
+name: pyright
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  typecheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v3
+        with:
+          enable-cache: true
+
+      - name: Set up Python
+        run: uv python install
+
+      - name: Install dependencies
+        run: uv sync --all-extras --dev
+
+      - name: Run pyright
+        run: uv run pyright
+```
+
+This adds a single `typecheck` job that installs `uv`, `python`, and my project
+dependencies, and then runs `uv run pyright` (just like I do locally) to perform
+type checking. If `pyright` discovers any type errors, the job will fail and I
+can view the output of the job to see what needs fixing. Once I have dealt with
+everything, the job will quietly pass with a green check mark.
+
+Here is [the PR](https://github.com/jbranchaud/py-vmt/pull/2) where I added this
+CI job.
@@ -0,0 +1,38 @@
+# Skip Specific Pytest Test Cases
+
+While using a failing test case to build a small new feature for
+[`py-vmt`](https://github.com/jbranchaud/py-vmt), I realized I needed to do some
+refactoring first. It wasn't significant enough to warrant stashing my current
+changes and switching to a different branch, so I kept all the changes around. I
+did find the initial failing test distracting from the refactoring I was trying
+to do. To temporarily shelve that failure, I can use a Pytest decorator to mark
+it as _skipped_.
+
+```python
+@pytest.mark.skip(reason="not yet implemented")
+def test_log_recent_activity():
+    runner = CliRunner()
+
+    # set up the data dir file with some existing session entries
+    initial_datetime = datetime.datetime(
+        2026, 3, 14, 15, 5, 11, 0, datetime.timezone.utc
+    )
+    with freeze_time(initial_datetime) as frozen_datetime:
+        # ...
+```
+
+The [`@pytest.mark.skip` decorator](https://docs.pytest.org/en/stable/how-to/skipping.html#skipping-test-functions)
+tells the Pytest runner to skip of that specific test case instead of executing
+it. In the test runner output, I'll see an `s` rather than a `.` or `F` and the
+summary will include it in a count of skipped tests:
+
+```
+=========================== 3 failed, 4 passed, 1 skipped in 0.09s ===========================
+```
+
+Another way to think about this is to mark this test case as _expected to fail_
+with `@pytest.mark.xfail`. That will display as an `x` and show up in the summary as:
+
+```
+=========================== 3 failed, 4 passed, 1 xfailed in 0.11s ===========================
+```
@@ -0,0 +1,52 @@
+# Sort A List Of Dataclass Instances
+
+Sorting lists of scalar values (integers, strings, floats, even booleans) in
+Python is simple because the natural ordering of the list elements will be used.
+We can call `sorted` on the list and it _just works_.
+
+```python
+>>> items = ["orange", "apple", "banana", "mango"]
+>>> sorted(items)
+['apple', 'banana', 'mango', 'orange']
+```
+
+However, if we have a list of non-scalar values, it is a little more complex. We
+have to give `sorted` some help with knowing how to sort things that don't have
+a natural ordering.
+
+Let's take this `dataclass` that represents a time-based `Session` as an
+example.
+
+```python
+from dataclasses import dataclass
+from datetime import datetime, timezone
+
+@dataclass
+class Session:
+    start_time: datetime
+    project_name: str
+    end_time: datetime | None = None
+
+    # plus several methods ...
+```
+
+If I have a list of `Session` instances that I want to sort, I have to give
+`sorted` a `key` to sort on. In the case of these `Session` instances, we'll
+pass a `lambda` that can be evaluated to determine the sort value (which needs
+to be sortable). `datetime` instances are sortable and I want to sort these
+sessions based on their `start_time` values.
+
+Here is a snippet from my `py_vmt` CLI where I make sure that each list of
+sessions in this day-by-day `dict` is sorted based on the `start_time`:
+
+```python
+for date in sessions_grouped_by_day.keys():
+    sessions_grouped_by_day[date].sort(
+        key=lambda session: session.start_time.time()
+    )
+```
+
+`sort` (and `sorted`) translates each item in the list to the values produced
+by the lambda and then sorts them by those values.
+
+[source](https://docs.python.org/3/howto/sorting.html)
@@ -0,0 +1,33 @@
+# Sort Normalized Version Of Data
+
+Let's say I have a list of names that I want to sort. However, because of
+inconsistency in how the data was entered, sometimes those names are capitalized
+and other times they are not. Using
+[`methodcaller`](https://docs.python.org/3/library/operator.html#operator.methodcaller),
+I can normalize the sorting `key` used when comparing list items.
+
+First, let's look at calling `sorted` with the list and no `key`:
+
+```python
+>>> sorted(["butler", "Jemisin", "le guin", "Erdrich"])
+['Erdrich', 'Jemisin', 'butler', 'le guin']
+```
+
+`butler` which starts with a `b` gets moved to the 3rd position because it is
+lowercase.
+
+To sort this list using a normalized comparison, we will use `methodcaller` to
+create a callable out of `lower` which is then passed as the sort `key`:
+
+```python
+>>> from operator import methodcaller
+>>> sorted(["butler", "Jemisin", "le guin", "Erdrich"], key=methodcaller("lower"))
+['butler', 'Erdrich', 'Jemisin', 'le guin']
+```
+
+That's the sort order I was originally hoping for.
+
+What `methodcaller` is doing is creating a callable function that will invoke
+`lower` with each string instance as the target. Conceptually similar to
+`"Erdrich".lower()` or even `getattr("Erdrich", "lower")()` (notice this needs
+to be immediately invoked).
@@ -0,0 +1,27 @@
+# Start The Debugger When A Test Errors
+
+While working on [some
+tests](https://github.com/jbranchaud/build-an-llm-from-scratch/blob/main/tests/chapter_02/test_bpe_tokenizer.py)
+for my Byte Pair Encoding tokenizer, I was running into an unexpected test
+failure. To better understand what was going on, I needed to inspect the state
+of the program around the time the code raised an exception.
+
+Instead of needing to manually set a breakpoint at the correct spot to begin
+debugging, I can run the test with the Pytest-supported `--pdb` flag. That's
+short for _python debugger_.
+
+> Start the interactive Python debugger on errors or KeyboardInterrupt
+
+What this does during a test run is opens you up to the interactive Python
+debugger at the exact moment an exception is raised. This gives you the ability
+to inspect values of the program state at that point in execution which could
+help inform the needed fix.
+
+```bash
+uv run pytest -vv --pdb -k "test_train_bpe"
+```
+
+There I am running a specific test that matches against `-k "test_train_bpe"`
+and the python debugger will start up if there is an error.
+
+See `uv run pytest --help` for more details.
@@ -0,0 +1,48 @@
+# Turn Method Into Cached Property On Class Instance
+
+I have a class that encapsulates a few things including a somewhat expensive
+data lookup from a file on disk. When this class is instantiated, it is
+short-lived and the data that gets pulled from the file on disk is considered
+fresh for the life of the instance.
+
+```python
+class CliContext:
+    def __init__(self, verbose: bool) -> None:
+        # ...
+        self.repo = JsonRepository()
+        # ...
+
+    def session_log(self) -> list[Session]:
+        return self.repo.load_session_log()
+```
+
+Because this method gets called from a couple places during a single lifecycle,
+this class would benefit from caching it via the [`@cached_property`
+decorator](https://docs.python.org/3/library/functools.html#functools.cached_property).
+
+```python
+from functools import cached_property
+
+class CliContext:
+    def __init__(self, verbose: bool) -> None:
+        # ...
+        self.repo = JsonRepository()
+        # ...
+
+    @cached_property
+    def session_log(self) -> list[Session]:
+        return self.repo.load_session_log()
+```
+
+Now `session_log` can be treated like a property instead of a method. That means
+when I want to load and access the session log, I can do `self.session_log` (no
+parentheses) like I would any other property. The first time I reference it, the
+method will run. Then that value will be cached and all subsequent references
+will use that cache.
+
+> Transform a method of a class into a property whose value is computed once and
+> then cached as a normal attribute for the life of the instance.
+
+Of course, anytime we use caching, we can create a footgun for ourselves. We
+have to be careful that our program doesn't evolve in such a way where the
+caching will create a subtle bug due to stale data.
@@ -0,0 +1,54 @@
+# Use `__post_init__` For `dataclass` Validations
+
+The [`dataclass`](https://docs.python.org/3/library/dataclasses.html) construct
+is a handy stdlib way of modeling some data with many improvements over a `dict`
+such as named attributes and type visibility.
+
+```python
+from dataclasses import dataclass
+from typing import ClassVar
+
+@dataclass
+class BPEConfig:
+    BASE_VOCAB_SIZE: ClassVar[int] = 256
+
+    vocab_size: int
+    special_tokens: list[str]
+```
+
+I want to enhance `BPEConfig` a little by validating the `vocab_size` which
+cannot be less than the `BASE_VOCAB_SIZE`. The
+[`__post_init__`](https://docs.python.org/3/library/dataclasses.html#dataclasses.__post_init__)
+method is a good place for this kind of validation.
+
+```python
+from dataclasses import dataclass
+from typing import ClassVar
+
+@dataclass
+class BPEConfig:
+    BASE_VOCAB_SIZE: ClassVar[int] = 256
+
+    vocab_size: int
+    special_tokens: list[str]
+
+    def __post_init__(self):
+        if self.vocab_size < self.BASE_VOCAB_SIZE:
+            msg = f"vocab_size ({self.vocab_size}) must be greater than or equal to BASE_VOCAB_SIZE ({self.BASE_VOCAB_SIZE})"
+            raise ValueError(msg)
+```
+
+With this in place, my program will fail fast if I try to use an invalid
+`vocab_size`:
+
+```python
+>>> BPEConfig(22, [])
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+  File "<string>", line 5, in __init__
+  File "/Users/lastword/dev/misc/build-an-llm/chapter_02/bpe_tokenizer.py", line 24, in __post_init__
+    raise ValueError(msg)
+ValueError: vocab_size (22) must be greater than or equal to BASE_VOCAB_SIZE (256)
+```
+
+This example is pulled directly from [the `BPETokenizer` I'm building](https://github.com/jbranchaud/build-an-llm-from-scratch/blob/d3fd0acd65c3e7419b2d15a64c8d74266d0488f6/chapter_02/bpe_tokenizer.py#L14-L24).
@@ -0,0 +1,64 @@
+# Validate Click Option With Callback
+
+I have a [click](https://click.palletsprojects.com/en/stable/) subcommand in my
+[`py-vmt` project](https://github.com/jbranchaud/py-vmt) that includes an
+`option` specified with the `--at` flag. This is what it originally looked like:
+
+```python
+# define `start` subcommand
+@cli.command()
+@click.argument("project-name")
+@click.option("--at", help='Relative time in past to start the time, e.g. "2 hours ago", "33 minutes ago"')
+@pass_cli
+def start(cli_ctx: CliContext, project_name: str, at: str | None) -> None:
+    # ...
+```
+
+The value of `at` needs to be in the past. I need a way validate that it is or
+otherwise bail early with a useful error message. The optional
+[`callback`](https://click.palletsprojects.com/en/stable/advanced/#callbacks-for-validation)
+to `@click.option` plus `click.BadParameter` are a good way to handle that.
+
+First, I define a callback handler that does the validation. I even take it a
+step further and have it return the transformed value (`datetime`) that the
+subcommand logic will need.
+
+```python
+def validate_past_time(_ctx, _param, value: str | None) -> datetime:
+    now = datetime.now(timezone.utc)
+
+    if value == None:
+        return now
+
+    start_at = time_helpers.parse_to_datetime(value)
+
+    if start_time == None or start_at > now:
+        raise click.BadParameter("must be a relative time in the past")
+
+    return start_at
+```
+
+I ignore the first two arguments because I only need to work with `value`. Value
+might be something like `"33 minutes ago"` and I attempt to transform that with
+`dateparser` into a `datetime` instance. If it can't be parsed or it isn't in
+the past, then I raise `click.BadParameter` which presents the user with useful
+usage details.
+
+This callback can then be incorporated into the subcommand like so:
+
+```python
+# define `start` subcommand
+@cli.command()
+@click.argument("project-name")
+@click.option(
+    "--at",
+    help='Relative time in past to start the time, e.g. "2 hours ago", "33 minutes ago"',
+    callback=validate_past_time
+)
+@pass_cli
+def start(cli_ctx: CliContext, project_name: str, at: datetime) -> None:
+    # ...
+```
+
+Now I can expect the incoming `at` option to be a `datetime` which helps
+simplify several lines of logic in the `start` implementation.
@@ -0,0 +1,37 @@
+# Define Conditional Routing Logic In Routes File
+
+I ran into a situation recently where I needed to intercept the behavior a
+common public-facing route in an app. Broadly, the route is for company specific
+rental pages with query parameters that correspond to their available inventory.
+
+What I needed was a way to display a demo version of that rental page ignoring
+everything else about how the request would otherwise be processed, validated,
+and rendered.
+
+Instead of introducing a bunch of weird conditional logic into this already
+complex rental controller, I was able to intercept the request at the routing
+layer when `demo=true` is set and send it to a different controller.
+
+Here is what that section of `config/routes.rb` looks like:
+
+```ruby
+get "rentals/new", to: "rental_demos#show",
+  as: :rental_demo,
+  constraints: ->(request) { request.params[:demo] == "true" }
+
+resources :rentals, only: %i[new create] do
+  # ...
+end
+```
+
+This specifies a `constraint` on the `get` handler matching for a given request.
+If the constraint isn't met, then the route handling logic proceeds where it
+will instead find a match with the original new rentals resource routing.
+
+Now I can reference a version of this URL that includes `demo=true` as a way of
+having an always-available realistic-looking version of the rental page even if
+one of these companies doesn't actively have available inventory.
+
+Those requests will get intercepted by the first matching route handler which
+will send them to the `RentalDemosController` instead of the
+`RentalsController`.
@@ -0,0 +1,46 @@
+# Halt ActionMailer Delivery With Callback
+
+`ActionMailer` supports callbacks, similar to `ActiveRecord`, like
+`before_deliver` and `after_delivery`. We can hook into the `before_deliver`
+callback to interrupt the delivery of an email that shouldn't go out.
+
+Here's the scenario: you schedule a bunch of payment reminders to go out to your
+customers that still need to make their latest payment. Let's say the daily job
+that schedules all of these reminders runs in the middle of the night, but
+schedules the emails to land in inboxes at a more reasonable time, like 10am.
+Between the time that the email is scheduled and it gets processed for delivery,
+a customer makes their payment. In that case, we no longer want to send that
+person an email reminder.
+
+To handle this scenario, we can have a `before_deliver` callback that checks the
+user's balance and raises `:abort` to halt the callback execution chain,
+effectively preventing the email from going out. We can even scope the callback
+to just the actions we care about using the `if` option and checking the
+`action_name`.
+
+```ruby
+class UserMailer < ApplicationMailer
+  before_deliver :abort_if_payment_is_current,
+    if: -> { action_name.in?(%w[payment_reminder past_due_invoice]) }
+
+  def payment_reminder
+    # ...
+  end
+
+  def past_due_invoice
+    # ...
+  end
+
+  private
+
+  def abort_if_payment_is_current
+    if @user.check_latest_balance.zero?
+      raise :abort
+    end
+  end
+end
+```
+
+See [Action Mailer
+Callbacks](https://guides.rubyonrails.org/action_mailer_basics.html#action-mailer-callbacks)
+for more details.
@@ -0,0 +1,46 @@
+# Define A Set Of Class Methods
+
+The most common way to define class methods is by defining them directly with
+`self` (the class in the current context) on a method by method basis:
+
+```ruby
+class User
+  def self.find_by(attrs)
+    # lookup logic ...
+  end
+end
+```
+
+If you have a group of class methods you want to define, you can stick them all
+within a `class << self` block which does similarly defines each of them as
+singleton methods of that class (`User` in this case):
+
+```ruby
+class User
+  class << self
+    def find_by_email(email)
+      # lookup logic ...
+    end
+
+    def find_by_last_name(last_name)
+      # lookup logic ...
+    end
+  end
+end
+```
+
+This opens the singleton class of `User` for modification, adding these two new
+methods.
+
+We can see those defined alongside all other direct and inherited class methods:
+
+```ruby
+> User.methods
+=>
+[:find_by_email,
+ :find_by_last_name,
+ :yaml_tag,
+ :allocate,
+ ...
+]
+```
@@ -0,0 +1,37 @@
+# Filter By Type
+
+In Ruby, we have several ways to check if something is a certain type (class or
+subclass). A couple common approaches you might see are `#is_a?` and `===`
+(case equality operator):
+
+```ruby
+> 3.is_a?(Integer)
+=> true
+> Integer === 3
+=> true
+> 3 === Integer
+=> false
+```
+
+Notice it is important to get the ordering of class and value right when using
+`===`.
+
+We can use these concepts to filter collections down to just those values of a
+certain type. We can also ditch those methods and instead use
+[`#grep`](https://ruby-doc.org/3.4.1/Enumerable.html#method-i-grep) to pattern
+match on the type directly.
+
+```ruby
+> nums = [1, :two, 3.0, 'four', 5, -> { 6 }, 0.7]
+=> [1, :two, 3.0, "four", 5, #<Proc:0x0000000123af0338 (irb):5 (lambda)>, 0.7]
+> nums.filter { it.is_a?(Numeric) }
+=> [1, 3.0, 5, 0.7]
+> nums.filter { Integer === it }
+=> [1, 5]
+> nums.grep(Integer)
+=> [1, 5]
+> nums.grep(Numeric)
+=> [1, 3.0, 5, 0.7]
+```
+
+[source](https://bsky.app/profile/lucianghinda.com/post/3mhi5xp3xhk25)
@@ -0,0 +1,63 @@
+# Use Rescue As Part Of Inline Statement
+
+In Ruby I typically think of `rescue` as block syntax that I can use to handle
+exceptions.
+
+```ruby
+begin
+  User.update!(password:)
+rescue
+  puts "There was an issue updating the password"
+end
+```
+
+The `rescue` keyword can also be used as part of an inline statement as a way of
+providing a _fallback_ value when the first part of the statement raises.
+
+For instance, if I'm trying to access some value on an array that happens to be
+`nil`, it is going to raise:
+
+```ruby
+> scores.first
+(irb):7:in '<main>': undefined method 'first' for nil (NoMethodError)
+```
+
+I can instead tack on a `rescue 0` which will give it `0` as a fallback value:
+
+```ruby
+> scores.first rescue 0
+=> 0
+```
+
+Of course, there are more idiomatic ways to handle this kind of situation in
+Ruby. Maybe something like this:
+
+```ruby
+> Array(scores).first || 0
+=> 0
+```
+
+Another way I've seen this inline rescue used is to print out the exception
+caused by that line of code, using `$!` (the global variable for the most
+recently raised exception).
+
+```ruby
+> scores.first rescue puts $!
+undefined method 'first' for nil
+=> nil
+```
+
+That is a one-liner for the following:
+
+```ruby
+begin
+  scores.first
+rescue => e
+  puts e
+end
+```
+
+The big caveat that goes with this is the same one that goes with any other
+blanket `rescue` block. If you are indiscriminately rescuing exceptions without
+being intentional about what you are rescuing and why, you could be potentially
+burying exceptions that you need to know about.
@@ -0,0 +1,52 @@
+# Add Default Task To List All Tasks
+
+One thing I like about [`just`](https://github.com/casey/just) is that if you
+run `just` by itself, the default behavior is to list out all the commands it
+can run.
+
+[Taskfile](https://github.com/go-task/task) technically does this as well, but
+with a warning at the end:
+
+```
+❯ task
+task: Available tasks for this project:
+* notes:              Interactive picker for notes tasks
+* notes:diff:         Show uncommitted changes in notes
+* notes:edit:         All-in-one edit, commit, and push notes
+* notes:log:          Show recent commit history for notes
+* notes:open:         Opens NOTES.md (syncs latest changes first) in default editor
+* notes:push:         Commit and push changes to notes submodule
+* notes:status:       Check status of notes submodule
+* notes:sync:         Sync latest changes from the notes submodule
+task: Task "default" does not exist
+```
+
+I prefer to tidy this up a little by adding `task --list` as the _default_ in my
+`Taskfile.yml`.
+
+```yml
+  default:
+    desc: Show available commands
+    cmds:
+      - task --list
+```
+
+Now when I run `task` with no arguments, I get this minutely nicer version:
+
+```
+❯ task
+Alias tip: t
+task: [default] task --list
+task: Available tasks for this project:
+* default:            Show available commands
+* notes:              Interactive picker for notes tasks
+* notes:diff:         Show uncommitted changes in notes
+* notes:edit:         All-in-one edit, commit, and push notes
+* notes:log:          Show recent commit history for notes
+* notes:open:         Opens NOTES.md (syncs latest changes first) in default editor
+* notes:push:         Commit and push changes to notes submodule
+* notes:status:       Check status of notes submodule
+* notes:sync:         Sync latest changes from the notes submodule
+```
+
+Notice there is no `task: Task "default" does not exist` warning at the end.
@@ -0,0 +1,22 @@
+# Browse And Search Help Docs
+
+There are a lot of tools that don't have dedicated `man` pages, but do have
+lengthy output when you pass them the `--help` flag.
+
+We can make those details easier to browse and searchable by piping them to
+`less`.
+
+```bash
+❯ uv run pytest --help | less
+```
+
+First, we see the top of the output inside `less` instead of bottom of the
+output right above our next terminal prompt.
+
+From `less`, we can use down and up arrows (or `j` and `k`) to navigate through
+the details. We can also jump to a specific word or phrase by searching -- type
+`/` and then the pattern we're trying to match. `n` and `N` to go to the next or
+previous match, respectively.
+
+See `man less` more more details. And if you like these improvements to viewing
+tool usage details, you may also be interested in [a better man page viewer](https://www.visualmode.dev/a-better-man-page-viewer).
@@ -0,0 +1,71 @@
+# Deduplicate List While Preserving Original Order
+
+Usually when I want to deduplicate a list coming out of some command, I'll reach
+for `sort | uniq`. This is a nice Unix trick where `uniq` removes consecutive
+duplicate lines which relies on `sort` first reorganizing all lines in
+alphabetically sorted order, bringing all duplicate lines together.
+
+The caveat to using `sort | uniq` (or even `sort -u`) is that it will reorder
+entries alphabetically. That means you'll lose the original order, which may
+have been important.
+
+```bash
+❯ echo "red green blue red yellow green blue red green" | tr ' ' '\n' | sort -u
+blue
+green
+red
+yellow
+```
+
+Another approach is to use `awk` which can deduplicate while preserving the
+order of entries as they first appear. This can be done with a pattern that
+records the count of each line in an associative array.
+
+```bash
+❯ echo "red green blue red yellow green blue red green" | tr ' ' '\n' | awk '!seen[$0]++'
+red
+green
+blue
+yellow
+```
+
+The above pattern accepts on the first occurrence of each line and rejects on
+any subsequent occurrences. That is done by adding `$0` (the current line) to
+`seen` (associative array that auto-initializes inline). If it doesn't exist in
+`seen` yet, then `0` is returned which is negated to a truthy value with `!`.
+That entry is then incremented from `0` to `1` via the `++`. As `awk` continues
+to process each line, `seen` is continually added to and incremented. The
+default _action_ for `awk` is to print the line. Those truthy lines are the ones
+that are printed.
+
+An example of where this might be useful is when creating a unique listing of
+all authors of a git repository while maintaining the order that they become
+committers. I wanted to show this with a high-contribution public repo that I
+worked on, so I referenced the [`egghead-next`
+repo](https://github.com/skillrecordings/egghead-next).
+
+```bash
+❯ git log --reverse --format='%an <%ae>' | awk '!seen[$0]++'
+Joel Hooks <joelhooks@gmail.com>
+johnlindquist <johnlindquist@gmail.com>
+John Lindquist <johnlindquist@gmail.com>
+William Johnson <w.alexander.johnson@gmail.com>
+depfu[bot] <23717796+depfu[bot]@users.noreply.github.com>
+Evgeniy Nagalskiy <evgeniy.nagalskiy@gmail.com>
+Taylor Bell <taylorbell@gmail.com>
+Maggie Appleton <maggie.fm.appleton@gmail.com>
+John Lindquist <johnlindquist@work.local>
+Vojta Holik <vojta@egghead.io>
+Daniel Miller <dealingwith@gmail.com>
+jh3y <jh3y@users.noreply.github.com>
+Jhey Tompkins <jh3y@users.noreply.github.com>
+Josh Branchaud <jbranchaud@gmail.com>
+Lauro Silva <57044804+laurosilvacom@users.noreply.github.com>
+LB <barth.laurie@gmail.com>
+kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>
+dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
+samuelhulick <samuel@samuelhulick.com>
+Ian Jones <jones58ian@gmail.com>
+Zac Jones <zacjones93@gmail.com>
+...
+```
@@ -0,0 +1,28 @@
+# Print Out File With Bat Without Formatting
+
+The [`bat`](https://github.com/sharkdp/bat) utility is my daily driver and
+replacement for anything used `cat` for before. I even have `bat` aliased to
+`cat` so that I never had to rewire my muscle memory for typing `cat`.
+
+Whether or not the creator of `cat` intended it, I'd guess that most terminal
+users' main use case is printing the contents of a file. `bat` does that way
+better with syntax highlighting, line numbers, and some layout formatting that
+puts lines around the output and a heading with the filename.
+
+All this formatting is great when I'm taking a quick look at a file. One way it
+gets in the way is when I'm trying to highlight and copy a few lines to my
+clipboard. Because the terminal is rendering lines, line numbers, and other
+formatting, all that fluff gets included on the clipboard.
+
+For this scenario, I can use the `-p` flag (or `--style=plain`) to print just
+the (syntax-highlighted) file contents without all the extra formatting.
+
+```bash
+bat -p app/models/users.rb
+
+# or
+bat --style=plain app/models/users.rb
+```
+
+Another way I could have approached this was to [ignore the alias of `cat` to
+`bat`](ignore-the-alias-when-running-a-command.md).
@@ -0,0 +1,64 @@
+# Reverse Each Line Of A File
+
+The [`rev` command](https://man7.org/linux/man-pages/man1/rev.1.html) can be
+used to reverse each line in a file. Every line is left where it is relative to
+other lines, but the contents of each line is reversed.
+
+So a file that contains the following text:
+
+```bash
+❯ cat stuff.md
+Three
+Two
+One
+go racecar go
+```
+
+can be piped to `rev` to get the following output:
+
+```bash
+❯ rev stuff.md
+eerhT
+owT
+enO
+og racecar og
+```
+
+This is an odd utility that doesn't have too much use that I can imagine. After
+a brief chat with Claude where I asked for some practical use cases, the one
+that stood out the most to me is to reverse a list of filenames, sort them, and
+then reverse them again (putting them back in readable order). This can shuffle
+filenames with similar endings near each other like source and test files.
+
+Here is a list of files for me [`py-vmt`
+project](https://github.com/jbranchaud/py-vmt):
+
+```bash
+❯ fd -t f .
+README.md
+pyproject.toml
+src/py_vmt/__init__.py
+src/py_vmt/cli.py
+src/py_vmt/session.py
+src/py_vmt/time_helpers.py
+tests/src/py_vmt/test_cli.py
+tests/src/py_vmt/test_session.py
+```
+
+Now I can pipe the output of that `fd` command through `rev | sort | rev` to get
+my files organized in a different way.
+
+```bash
+❯ fd -t f . | rev | sort | rev
+README.md
+pyproject.toml
+src/py_vmt/__init__.py
+tests/src/py_vmt/test_cli.py
+src/py_vmt/cli.py
+tests/src/py_vmt/test_session.py
+src/py_vmt/session.py
+src/py_vmt/time_helpers.py
+```
+
+Again the value of doing something like this is a bit tenuous. At the very least
+it is fun to know about.
@@ -0,0 +1,30 @@
+# Use The Readline Keybindings Anywhere
+
+There are these features of the "shell" that I've often heard called _emac
+keybindings_. These are things like `ctrl-a` (move the cursor to the beginning
+of the line) and `ctrl-e` (move the cursor to the end of the line) that I use
+every single day. There are several others that are in my heavy rotation,
+however, I learned about a couple more reading through [Shell Tricks That
+Actually Make Life Easier (And Save Your
+Sanity)](https://blog.hofstede.it/shell-tricks-that-actually-make-life-easier-and-save-your-sanity/).
+
+These are [Readline commands](https://www.gnu.org/software/bash/manual/html_node/Bindable-Readline-Commands.html)
+(or keybindings) which means they are supported by anything that uses Readline
+under the hood. So while you might be using these to great effect in `bash` and
+`zsh`, you should look for other places they are available.
+
+A non-exhaustive list includes:
+
+- Ruby's `irb`
+- Python's `python`
+- Node.js' `node`
+- PostgreSQL's `psql`
+- Claude Code
+
+And many more similar REPLs and command line tools.
+
+Try these keybindings out in one of your favorites and when you're done hit
+`ctrl-c` to exit out of it.
+
+PS. subsets of these keybindings are sometimes supported in unexpected places
+like the Chrome URL bar.
@@ -0,0 +1,25 @@
+# Show All Linear Keyboard Shortcuts
+
+Linear, the project management software, puts an incredible amount of attention
+to detail into the UX and UI of their app. This includes making the app a power
+tool for power users with tons of keyboard shortcuts.
+
+I'm aware of some of Linear's keyboard shortcuts, but the discoverability of
+many of them is tough.
+
+A great way to list and browse through all of them right in the app is with
+`Cmd+/`.
+
+They are organized into sections that I can scroll through. There is also a
+search box at the top of this _Keyboard Shortcuts_ panel where I can narrow down
+the results to those that match a term.
+
+A few that I'm finding immediately useful are:
+
+- `gi` to go to my _Inbox_ in the current workspace
+- `gm` to go to _My Issues_ in the current workspace
+- `ow` to open a picker to switch between workspaces
+
+Note: the _Keyboard Shortcuts_ panel lists many of the letter-based shortcuts as
+being capitalized. I've found that these don't work when I hold shift. For that
+reason, I've listed the above shortcuts with lowercase letters.
@@ -0,0 +1,40 @@
+# View Nicely Formatted Markdown From Terminal
+
+The [`glow`](https://github.com/charmbracelet/glow) utility is CLI markdown
+renderer written in Go. It is part of the CCU
+([charmbraclet](https://github.com/charmbracelet) CLI universe). And yes, I just
+made up _CCU_.
+
+`glow` is great because it processes and outputs a markdown file with some
+styling tailored to a terminal including:
+
+- colors to emphasize things like headings
+- styling of inline code snippets
+- syntax highlighting for fenced code blocks
+- rendering of markdown tables
+- and a lot more that I'm not thinking to mention
+
+In the past I've installed this with `brew`, but I currently manage my `glow`
+install with [this mise config](https://github.com/jbranchaud/dotfiles/blob/main/config/mise/config.toml?plain=1#L66).
+
+To view a nicely rendered markdown file, I can run:
+
+```bash
+$ glow README.md
+```
+
+For long markdown files like [this `README.md`](https://github.com/jbranchaud/til/blob/master/README.md), this
+doesn't work too well because it renders until the end and spits you at at the
+bottom.
+
+Fortunately, `glow` has a built-in pager that maintains all the styling while
+allowing you to navigate and search similar to `less`.
+
+```bash
+$ glow -p README.md
+```
+
+There is also a TUI version (`-t`), but I find that less intuitive and useful
+than the pager.
+
+See `glow --help` for more details.
@@ -0,0 +1,44 @@
+# List Available Zle Keybindings
+
+Unlike `bash` which uses `readline`, `zsh` has its own implementation of a line
+editing library -- `zle`. A lot of the core bindings between the two are the
+same, e.g. `Ctrl-a` and `Ctrl-e` to go the beginning and end of the command line
+prompt, respectively.
+
+All available `zle` keybindings can be listed out by running `bindkey` without
+any arguments.
+
+The best way to check out an unaltered version of this list is by starting a
+fresh `zsh` process with no RCS files loaded in. The `-f` flag does that. Note
+though that when `zsh` is starting fresh, it has to decide whether to start in
+_Emacs_ mode or _Vi_ mode. If it sees that your default editor is something like
+`vi`, `vim` or `nvim`, then it will start you in _Vi_ mode.
+
+Starting in _Vi_ mode can be confusing because none of the standard _Emacs_
+keybindings like `Ctrl-a` and `Ctrl-e` are available in that context. So first
+ensure you're in _Emacs_ mode by running:
+
+```sh
+❯ zsh -f
+lastword% bindkey -e
+```
+
+Now you can list out all the keybindings:
+
+```sh
+lastword% bindkey
+"^@" set-mark-command
+"^A" beginning-of-line
+"^B" backward-char
+"^D" delete-char-or-list
+"^E" end-of-line
+"^F" forward-char
+"^G" send-break
+"^H" backward-delete-char
+"^I" expand-or-complete
+"^J" accept-line
+"^K" kill-line
+...
+```
+
+See `man zshzle` for more details on `zle` and `bindkey`.
Author	SHA1	Message	Date
jbranchaud	d4766dad95	Create a shared task to deduplicate logic listing recent TILs	2026-07-05 18:25:02 -05:00
jbranchaud	5f4308c1af	Add two new browsing tasks for popping open latest TIL in browser	2026-07-05 18:09:31 -05:00
jbranchaud	8c463a90e3	Add Deduplicate List While Preserving Original Order as a Unix TIL	2026-07-05 17:55:06 -05:00
jbranchaud	329267c7a2	Add Set Up Pyright Type Checking In GitHub as a Python TIL	2026-07-04 17:14:33 -05:00
jbranchaud	12180acb02	Add Generate Permutations Of All Valid 9-ball Racks as a Math TIL	2026-07-03 21:44:35 -04:00
jbranchaud	8f722061b4	Add Enable Pyright Type Checking In Cursor as a Python TIL	2026-06-29 11:44:11 -04:00
jbranchaud	a126b13d7c	Add Print Out File With Bat Without Formatting as a Unix TIL	2026-06-28 11:53:18 -05:00
jbranchaud	0ae3f14c25	Add Define Typed Class Interface With Protocol as a Python TIL	2026-06-27 13:10:51 -05:00
jbranchaud	b91527db30	Add Use Rescue As Part Of Inline Statement as a Ruby TIL	2026-06-26 11:54:31 -05:00
jbranchaud	c8f8c2c1a3	Add Turn Method Into Cached Property On Class Instance as a Python TIL	2026-06-25 11:30:18 -05:00
jbranchaud	c397e35ffd	Add Process JSON Output From gh With jq as a GitHub TIL	2026-06-24 16:56:26 -05:00
jbranchaud	bbb28fd811	Add Show All Linear Keyboard Shortcuts as a Workflow TIL	2026-06-23 03:31:38 -05:00
jbranchaud	950e2f861a	Add Define Conditional Routing Logic In Routes File as a Rails TIL	2026-06-22 17:52:13 -05:00
jbranchaud	20bbdb6d55	Add Make Secure Temp File For Atomic Write as a Python TIL	2026-06-22 17:26:14 -05:00
jbranchaud	03c11f9042	Add Clean Up Item Layout In Finder Window as a Mac TIL	2026-06-10 14:01:42 -05:00
jbranchaud	cea6c75e1c	Add Check Precondition Before Click Arg Parsing as a Python TIL	2026-05-24 17:35:11 -05:00
jbranchaud	539cbbefa6	Add Halt ActionMailer Delivery With Callback as a Rails TIL	2026-05-23 12:33:02 -05:00
jbranchaud	3eddb54053	Add Argument Defaults Are Evaluated When Function Is Defined as a Python TIL	2026-05-21 21:53:46 -05:00
jbranchaud	49628a7849	Add Read The Lid Angle Sensor For A MacBook as a Mac TIL	2026-05-20 12:39:28 -05:00
jbranchaud	3919b721cd	Add Distinguish Sessions With Different Colors as a Claude Code TIL	2026-05-19 11:20:20 -05:00
jbranchaud	9c65e5c0b3	Add Get User's Preferred Language From Browser as a JavaScript TIL	2026-05-14 11:27:58 -05:00
jbranchaud	e58ffffda0	Add Validate Click Option With Callback as a Python TIL	2026-05-09 20:28:01 -05:00
jbranchaud	d87e125472	Add Cloudflare Allows CNAME For Apex Domain as a Devops TIL	2026-05-08 15:02:00 -05:00
jbranchaud	facc606014	Add Get Quotient And Remainder In One Operation as a Python TIL	2026-05-05 16:57:07 -05:00
jbranchaud	be103b52dd	Add Programmatically Grab SHA For Head Commit as a Git TIL	2026-05-04 16:12:31 -05:00
jbranchaud	3402428aad	Add Reclassify Certain Packagaes As Dev Dependencies as a Python TIL	2026-05-04 14:30:12 -05:00
jbranchaud	0c00e47141	Add Open File To Specific Line In Browser as a GitHub TIL	2026-05-03 19:18:14 -05:00
jbranchaud	1c90fdd823	Add Get Absolute Seconds From `timedelta` Object as a Python TIL	2026-05-02 16:56:49 -05:00
jbranchaud	bf3991ce04	Add a missing link to the latest TIL	2026-05-02 12:37:50 -05:00
jbranchaud	3db5af78c1	Add View Nicely Formatted Markdown From Terminal as a Workflow TIL	2026-05-02 12:36:15 -05:00
jbranchaud	a8c35e2458	Add Define Sequence Of Tests With Parametrize Decorator as a Python TIL	2026-05-01 21:30:20 -05:00
jbranchaud	c0ad3cee4d	Add Assert Is Only A Development Check as a Python TIL	2026-05-01 17:01:14 -05:00
jbranchaud	9bd1bb413a	Add Reverse Each Line Of A File as a Unix TIL	2026-05-01 16:07:15 -05:00
jbranchaud	ab8331000f	Add Sort Normalized Version Of Data as a Python TIL	2026-04-29 11:34:32 -05:00
jbranchaud	cd54360925	Add missing terminal prompt in code block	2026-04-23 12:24:23 -05:00
jbranchaud	75421685ea	Add List PRs Awaiting Your Review as a GitHub TIL	2026-04-22 19:53:32 -05:00
jbranchaud	0cb5890fc0	Add Access Variables Outside Loop Scope as a Python TIL	2026-04-21 17:48:06 -05:00
jbranchaud	7de0e70d78	Add Define A Set Of Class Methods as a Ruby TIL	2026-04-17 10:51:31 -04:00
jbranchaud	36934aa56f	Add Make Dataclass Sortable By Specific Field as a Python TIL	2026-04-15 22:53:29 -05:00
jbranchaud	2cd465bb08	Add Display All Git Log Entries In My Local Timezone as a Git TIL	2026-04-09 12:54:59 -05:00
jbranchaud	6ad376885b	Add Stash The Current Prompt To Send Another First as a Claude Code TIL	2026-04-08 13:35:11 -05:00
jbranchaud	0c4702be97	Add Count Number Of Tokens In A File as an LLM TIL	2026-04-03 09:23:11 -05:00
jbranchaud	b873f86f5b	Add Sort A List Of Dataclass Instances as a Python TIL	2026-04-01 20:38:20 -05:00
jbranchaud	1120bb2018	Add Avoid Vulnerabilities In New Package Versions as a PNPM TIL	2026-03-31 11:33:13 -05:00
jbranchaud	906253b7dc	Add List Available Zle Keybindings as a Zsh TIL	2026-03-30 13:45:35 -05:00
jbranchaud	b4920c0397	Add Skip Specific Pytest Test Cases as a Python TIL	2026-03-29 11:05:32 -05:00
jbranchaud	119cc15c9a	Add a couple more examples to most recent TIL	2026-03-29 01:22:39 -05:00
jbranchaud	1a4589f8f7	Add Use The Readline Keybindings Anywhere as a Unix TIL	2026-03-27 22:38:14 -05:00
jbranchaud	5f35404433	Add Avoid Modification With Frozen Dataclass as a Python TIL	2026-03-25 18:52:19 -05:00
jbranchaud	1766e45134	Add Start The Debugger When A Test Errors as a Python TIL	2026-03-23 21:27:10 -05:00
jbranchaud	c875652725	Add Add Default Task To List All Tasks as a Taskfile TIL	2026-03-23 21:12:44 -05:00
jbranchaud	8af252f232	Add Use `__post_init__` For `dataclass` Validations as a Python TIL	2026-03-22 14:37:59 -05:00
jbranchaud	eb0a7e1b3d	Link to the VisualMode blog from the README	2026-03-21 13:28:25 -05:00
jbranchaud	c1cd40311f	Add Browse And Search Help Docs as a Unix TIL	2026-03-21 12:34:49 -05:00
jbranchaud	c744117eff	Add Deduplicate A List Into A Tuple as a Python TIL	2026-03-21 12:33:09 -05:00
jbranchaud	329ce1aa3e	Add Filter By Type as a Ruby TIL	2026-03-20 09:18:10 -05:00
jbranchaud	16082177aa	Add Create A Range Of Descending Values as a Python TIL	2026-03-19 00:25:32 -05:00
jbranchaud	2276a57445	Add Look Inside Pytest tmp_path as a Python TIL	2026-03-18 21:03:51 -05:00
jbranchaud	ceaab3da4f	Add Reveal Location Of File In Finder.app as a Mac TIL	2026-03-16 09:40:18 -05:00
jbranchaud	c7711ca337	Add Control Passing Of Time In Tests as a Python TIL	2026-03-14 16:18:36 -05:00