Merge 460473a87f into a547b9cee2

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1628 TILs and counting..._
+_1634 TILs and counting..._
 
 See some of the other learning resources I work on:
 - [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
@@ -114,6 +114,7 @@ If you've learned something here, support my efforts writing daily TILs by
 
 - [AWS CLI Requires Groff Executable](aws/aws-cli-requires-groff-executable.md)
 - [Find And Follow Server Logs](aws/find-and-follow-server-logs.md)
+- [List RDS Snapshots With Matching Identifier Prefix](aws/list-rds-snapshots-with-matching-identifier-prefix.md)
 - [Output CLI Results In Different Formats](aws/output-cli-results-in-different-formats.md)
 - [Sign Up User With Email And Password](aws/sign-up-user-with-email-and-password.md)
 - [SSH Into An ECS Container](aws/ssh-into-an-ecs-container.md)
@@ -134,6 +135,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Duplicate The Current Tab](chrome/duplicate-the-current-tab.md)
 - [Easier Access To Network Throttling Controls](chrome/easier-access-to-network-throttling-controls.md)
 - [Keybinding To Focus The Address Bar](chrome/keybinding-to-focus-the-address-bar.md)
+- [Open Current Tab In New Window With Vimium](chrome/open-current-tab-in-new-window-with-vimium.md)
 - [Pause JavaScript From The Source DevTools Panel](chrome/pause-javascript-from-the-source-devtools-panel.md)
 - [Navigate The Browser History With Vimium](chrome/navigate-the-browser-history-with-vimium.md)
 - [Pretty Print Tabular Data](chrome/pretty-print-tabular-data.md)
@@ -1035,6 +1037,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Ensure A Rake Task Cannot Write Data](rails/ensure-a-rake-task-cannot-write-data.md)
 - [Ensure Migrations Use The Latest Schema](rails/ensure-migrations-use-the-latest-schema.md)
 - [Ensure Record Saved With after_commit Callback](rails/ensure-record-saved-with-after-commit-callback.md)
+- [Filter ActiveModel Validation Errors](rails/filter-active-model-validation-errors.md)
 - [Filter ActiveStorage Blobs To Only Images](rails/filter-active-storage-blobs-to-only-images.md)
 - [Find Or Create A Record With FactoryBot](rails/find-or-create-a-record-with-factory-bot.md)
 - [Find Records With Multiple Associated Records](rails/find-records-with-multiple-associated-records.md)
@@ -1539,6 +1542,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Count The Number Of ripgrep Pattern Matches](unix/count-the-number-of-ripgrep-pattern-matches.md)
 - [Count The Number Of Words On A Webpage](unix/count-the-number-of-words-on-a-webpage.md)
 - [Create A File Descriptor with Process Substitution](unix/create-a-file-descriptor-with-process-substitution.md)
+- [Create A Filename With The Current Date](unix/create-a-filename-with-the-current-date.md)
 - [Create A Sequence Of Values With A Step](unix/create-a-sequence-of-values-with-a-step.md)
 - [Curl With Cookies](unix/curl-with-cookies.md)
 - [Curling For Headers](unix/curling-for-headers.md)
@@ -1586,6 +1590,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Grep For Files Without A Match](unix/grep-for-files-without-a-match.md)
 - [Grep For Files With Multiple Matches](unix/grep-for-files-with-multiple-matches.md)
 - [Grep For Multiple Patterns](unix/grep-for-multiple-patterns.md)
+- [Have Script ShellCheck Itself When Executing](unix/have-script-shellcheck-itself-when-executing.md)
 - [Hexdump A Compiled File](unix/hexdump-a-compiled-file.md)
 - [Ignore A Directory During ripgrep Search](unix/ignore-a-directory-during-ripgrep-search.md)
 - [Ignore The Alias When Running A Command](unix/ignore-the-alias-when-running-a-command.md)
@@ -1696,6 +1701,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Breaking The Undo Sequence](vim/breaking-the-undo-sequence.md)
 - [Buffer Time Travel](vim/buffer-time-travel.md)
 - [Build And Install A Go Program](vim/build-and-install-a-go-program.md)
+- [Bypass On-Save Tooling When Writing File](vim/bypass-on-save-tooling-when-writing-file.md)
 - [Case-Aware Substitution With vim-abolish](vim/case-aware-substitution-with-vim-abolish.md)
 - [Case-Insensitive Substitution](vim/case-insensitive-substitution.md)
 - [Center The Cursor](vim/center-the-cursor.md)

aws/list-rds-snapshots-with-matching-identifier-prefix.md

@@ -0,0 +1,29 @@
+# List RDS Snapshots With Matching Identifier Prefix
+
+I'm working on a script that manually creates a snapshot which it will then
+restore to a temporary database that I can scrub and dump. The snapshots that
+this script takes are _manual_ and they are named with identifiers that have a
+defining prefix (`dev-snapshot-`). Besides the few snapshots created by this
+script, there are tons of automated snapshots that RDS creates for
+backup/recovery purposes.
+
+I want to list any snapshots that have been created by the script. I can do
+this with the `describe-db-snapshots` command and some filters.
+
+```bash
+$ aws rds describe-db-snapshots \
+  --snapshot-type manual \
+  --query "DBSnapshots[?starts_with(DBSnapshotIdentifier, 'dev-snapshot-')].DBSnapshotIdentifier" \
+  --no-cli-pager
+
+[
+    "dev-snapshot-20250327-155355"
+]
+```
+
+There are two key pieces. The `--snapshot-type manual` filter excludes all
+those automated snapshots. The `--query` both filters to any snapshots whose
+identifier `?starts_with` the prefix `dev-snapshot-` and then refines the
+output to just the `DBSnapshotIdentifier` instead of the entire JSON object.
+
+[source](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-snapshots.html)

chrome/open-current-tab-in-new-window-with-vimium.md

@@ -0,0 +1,14 @@
+# Open Current Tab In New Window With Vimium
+
+Sometime I have a busy Chrome window going with a bunch of tabs open for
+various lines of work as well as a number of tabs that I've neglected to close.
+I then open a new tab, find something useful, and realize I'm at a "branching
+point". I'm about to start in on a specific chunk of work that will probably
+involve opening several more tabs and switch back and forth between some
+dashboards. I want to start all of this from a fresh slate -- or at least from
+a fresh Chrome window.
+
+With [Vimium](https://github.com/philc/vimium), I can hit `W` (`Shift-w`) to
+have the current tab move from the current window to a new window. The original
+window, minus that one tab, will be left as is so that I can go back to it as
+needed.

javascript/immutable-remove-with-the-spread-operator.md

@@ -15,10 +15,8 @@ const remove = (items,index) => {
 };
 
 const list = [1,2,3,4,5];
-remove(list, 2);
-// [1,2,3,4]
-list
-// [1,2,3,4,5]
+remove(list, 2); // [1,2,4,5]
+// list still [1,2,3,4,5]
 ```
 
 It only took a couple lines of code and immutability is baked in.

rails/filter-active-model-validation-errors.md

@@ -0,0 +1,43 @@
+# Filter ActiveModel Validation Errors
+
+Now that `ActiveModel` has a custom `Errors` class (as of Rails 6.1) instead of
+a hash, we get some useful functionality. Namely, we get a [`#where`
+method](https://api.rubyonrails.org/classes/ActiveModel/Errors.html#method-i-where)
+that allows us to filter errors based on the attribute name, type of
+validation, and even properties of that validation.
+
+Here I have created a new `Book` without any attributes. All of its validations
+are going to fail and we are going to have an `ActiveModel::Errors` object
+attached to it with several errors.
+
+```ruby
+> book = Book.new
+=>
+#<Book:0x00000001110397a8
+...
+> book.valid?
+=> false
+> book.errors
+=> #<ActiveModel::Errors [#<ActiveModel::Error attribute=added_by, type=blank, options={:message=>:required, :if=>#<Proc:0x0000000110096260 /Users/jbranchaud/.asdf/installs/ruby/3.2.2/lib/ruby/gems/3.2.0/gems/activerecord-7.2.1/lib/active_record/associations/builder/belongs_to.rb:130 (lambda)>}>, #<ActiveModel::Error attribute=title, type=blank, options={}>, #<ActiveModel::Error attribute=title, type=too_short, options={:count=>3}>, #<ActiveModel::Error attribute=author, type=blank, options={}>, #<ActiveModel::Error attribute=publication_date, type=blank, options={}>]>
+```
+
+Let's say I want to check for a specific validation error. I can use `#where`
+to filter down by attribute name (e.g. `:title`). I can filter even further by
+including the validation type as well (e.g. `:too_short`).
+
+```ruby
+> book.errors.where(:title)
+=>
+[#<ActiveModel::Error attribute=title, type=blank, options={}>,
+ #<ActiveModel::Error attribute=title, type=too_short, options={:count=>3}>]
+> book.errors.where(:title, :too_short)
+=> [#<ActiveModel::Error attribute=title, type=too_short, options={:count=>3}>]
+> book.errors.where(:title, :too_short).first.message
+=> "is too short (minimum is 3 characters)"
+> book.errors.where(:title, :too_short).first.full_message
+=> "Title is too short (minimum is 3 characters)"
+```
+
+This filtering could be used as part of conditional checks for what flash
+message gets displayed to the user or even what route/view gets rendered in
+response to the error.

unix/create-a-filename-with-the-current-date.md

@@ -0,0 +1,38 @@
+# Create A Filename With The Current Date
+
+I was recently working on a script to pull a scrubbed database dump using the
+`pg_dump` Postgres utility. Ultimately, the script does something like this to
+dump a remote database to a local file:
+
+```bash
+pg_dump \
+  -h host.region.rds.amazonaws.com \
+  -U db_username \
+  -d db_name \
+  -F c \
+  -f scrubbed-database-$(date +%Y-%m-%d).dump
+```
+
+Notice the last part of that command where we define the name of the dump file.
+It has a `$(...)` that is used to run and interpolate a command as part of the
+filename.
+
+Here is that `date` command run on its own:
+
+```bash
+$ date +%Y-%m-%d
+2025-04-02
+```
+
+In the above command, that would mean if I were to run it today, I'd get
+`scrubbed-database-2025-04-02.dump`.
+
+This approach can be used with any command where you are producing a file that
+you want to be dated or timestamped.
+
+Here is another example that incorporates the time as well:
+
+```bash
+$ touch $(date +%Y%m%d_%H%M%S)-migration.sql
+# => 20250402_092442-migration.sql
+```

unix/have-script-shellcheck-itself-when-executing.md

@@ -0,0 +1,60 @@
+# Have Script ShellCheck Itself When Executing
+
+The [ShellCheck](https://www.shellcheck.net/) utility can be run against bash
+scripts to check if there are any warnings or errors we should fix. It works
+great as long as we remember to run it.
+
+I wondered if I could make it easier on myself by not having to remember to run
+it. What if my bash script were to `shellcheck` itself?
+
+Here is an example script where at the beginning it looks for and runs the
+`shellcheck` utility against `$0` (the path of the script). This is kind of
+meta. As the script is executing, it has an external program run against the
+entire contents of itself. If there are any `shellcheck` issues, they get
+displayed and the program exits early.
+
+```bash
+#!/bin/bash
+
+# Exit immediately if any command fails
+set -e
+
+# Self-validation using ShellCheck
+if command -v shellcheck &> /dev/null; then
+    echo "Validating script with ShellCheck..."
+
+    # $0 refers to the script itself
+    if ! shellcheck "$0"; then
+        echo "ShellCheck found issues in the script. Exiting."
+        exit 1
+    fi
+    echo "Script validation passed."
+else
+    echo "Warning: ShellCheck not found. Skipping validation."
+fi
+
+echo "Script execution continuing..."
+
+# shellcheck warning here
+read -p "Continue with current operation? (yes/no): " CONTINUE_WITH_EXISTING
+if [[ ! "$CONTINUE_WITH_EXISTING" =~ ^[Yy][Ee][Ss]$ ]]; then
+    echo "Operation cancelled."
+    exit 1
+fi
+```
+
+This last bit of the script with the `read` command will trigger a warning from
+`shellcheck`.
+
+```bash
+$ ./check.sh
+Validating script with ShellCheck...
+
+In ./check.sh line 23:
+read -p "Continue with current operation? (yes/no): " CONTINUE_WITH_EXISTING
+^--^ SC2162 (info): read without -r will mangle backslashes.
+
+For more information:
+  https://www.shellcheck.net/wiki/SC2162 -- read without -r will mangle backs...
+ShellCheck found issues in the script. Exiting.
+```

vim/bypass-on-save-tooling-when-writing-file.md

@@ -0,0 +1,30 @@
+# Bypass On-Save Tooling When Writing File
+
+Every once in a while I run into an issue where my code formatters or linters
+are misconfigured for a project. I try to save a file and it applies formatting
+that I don't want. Or in an extreme case, the error ouput of the tool is what
+overwrites the file.
+
+I need to troubleshoot my dev tooling eventually, but I don't want to get
+sidetracked at the moment. I just want to save the file. What can I do?
+
+Tools like linters and code formatters are typically hooked up to Vim via
+autocommands on certain actions like `FileWrite*` or `BufWrite*`. We can
+execute a Vim command like writing a file (`w`) while disregarding autocommands
+like so:
+
+```vim
+:noautocmd w
+```
+
+or, write and quit:
+
+```vim
+:noautocmd wq
+```
+
+This disables all autocommands for this one command. The file gets saved and
+the misconfigured formatters and linters don't clobber the changes you
+intended.
+
+See `:h noautocmd` for more details.