Merge 295fe153ad into 2916fbc3b5

Hello, I've added a small blockquote below the description to indicate that this method of accessing an indefinite number of function arguments has been superseded by the use of the spread operator via rest parameters for ES6+ compatibility.

README.md

@@ -10,12 +10,15 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1595 TILs and counting..._
+_1603 TILs and counting..._
 
 See some of the other learning resources I work on:
 - [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
 - [Vim Un-Alphabet](https://www.youtube.com/playlist?list=PL46-cKSxMYYCMpzXo6p0Cof8hJInYgohU)
 
+If you've learned something here, support my efforts writing daily TILs by
+[buying me a coffee](https://buymeacoffee.com/jbranchaud) 💜
+
 ---
 
 ### Categories
@@ -111,6 +114,8 @@ See some of the other learning resources I work on:
 - [AWS CLI Requires Groff Executable](aws/aws-cli-requires-groff-executable.md)
 - [Find And Follow Server Logs](aws/find-and-follow-server-logs.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)
+- [Use Specific AWS Profile With CLI](aws/use-specific-aws-profile-with-cli.md)
 
 ### Brew
 
@@ -178,6 +183,7 @@ See some of the other learning resources I work on:
 - [Define HSL Colors With Alpha Values](css/define-hsl-colors-with-alpha-values.md)
 - [Display Responsive iframe Maintaining Aspect Ratio](css/display-responsive-iframe-maintaining-aspect-ratio.md)
 - [Dry Up SCSS With Mixins](css/dry-up-scss-with-mixins.md)
+- [Filter Blur Requires Expensive Calculation](css/filter-blur-requires-expensive-calculation.md)
 - [Give Elements The Same Width With Flexbox](css/give-elements-the-same-width-with-flexbox.md)
 - [Let Pointer Events Pass Through An Element](css/let-pointer-events-pass-through-an-element.md)
 - [Lighten And Darken With CSS Brightness Filter](css/lighten-and-darken-with-css-brightness-filter.md)
@@ -950,6 +956,8 @@ See some of the other learning resources I work on:
 
 ### Rails
 
+- [Access Secrets In A Rails 5.2 App](rails/access-secrets-in-a-rails-5-2-app.md)
+- [ActiveRecord Query For This Or That](rails/active-record-query-for-this-or-that.md)
 - [Add A Check Constraint To A Table](rails/add-a-check-constraint-to-a-table.md)
 - [Add A Database Index If It Does Not Already Exist](rails/add-a-database-index-if-it-does-not-already-exist.md)
 - [Add A Foreign Key Reference To A Table](rails/add-a-foreign-key-reference-to-a-table.md)
@@ -958,8 +966,7 @@ See some of the other learning resources I work on:
 - [Add ActiveRecord Error Not Tied To Any Attribute](rails/add-activerecord-error-not-tied-to-any-attribute.md)
 - [Add React With Webpacker To A New Rails App](rails/add-react-with-webpacker-to-a-new-rails-app.md)
 - [Add timestamptz Columns With The Migration DSL](rails/add-timestamptz-columns-with-the-migration-dsl.md)
-- [Access Secrets In A Rails 5.2 App](rails/access-secrets-in-a-rails-5-2-app.md)
-- [ActiveRecord Query For This Or That](rails/active-record-query-for-this-or-that.md)
+- [Adjust The Production Log Level](rails/adjust-the-production-log-level.md)
 - [Advance The Date](rails/advance-the-date.md)
 - [Allow Associations To Be Optional](rails/allow-associations-to-be-optional.md)
 - [Allow List Params Anywhere With Strong Params](rails/allow-list-params-anywhere-with-strong-params.md)
@@ -1002,6 +1009,7 @@ See some of the other learning resources I work on:
 - [Different Ways To Add A Foreign Key Reference](rails/different-ways-to-add-a-foreign-key-reference.md)
 - [Disambiguate Where In A Joined Relation](rails/disambiguate-where-in-a-joined-relation.md)
 - [Empty find_by Returns First Record](rails/empty-find-by-returns-first-record.md)
+- [Enforce Locals Passed To A Partial](rails/enforce-locals-passed-to-a-partial.md)
 - [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)
@@ -1532,6 +1540,7 @@ See some of the other learning resources I work on:
 - [Find Newer Files](unix/find-newer-files.md)
 - [Find Occurrences Of Multiple Values With Ripgrep](unix/find-occurrences-of-multiple-values-with-ripgrep.md)
 - [Find Top-Level Directories Matching A Pattern](unix/find-top-level-directories-matching-a-pattern.md)
+- [Fix Previous Command With fc](unix/fix-previous-command-with-fc.md)
 - [Fix Shim Path After asdf Upgrade](unix/fix-shim-path-after-asdf-upgrade.md)
 - [Fix Unlinked Node Binaries With asdf](unix/fix-unlinked-node-binaries-with-asdf.md)
 - [Forward Multiple Ports Over SSH](unix/forward-multiple-ports-over-ssh.md)
@@ -1572,6 +1581,7 @@ See some of the other learning resources I work on:
 - [List Parent pid With ps](unix/list-parent-pid-with-ps.md)
 - [List Stats For A File](unix/list-stats-for-a-file.md)
 - [List The Available JDKs](unix/list-the-available-jdks.md)
+- [List The PID And Name Of Current Shell Process](unix/list-the-pid-and-name-of-current-shell-process.md)
 - [List The Stack Of Remembered Directories](unix/list-the-stack-of-remembered-directories.md)
 - [List TXT DNS Records For A Domain](unix/list-txt-dns-records-for-a-domain.md)
 - [Load Env Vars In Bash Script](unix/load-env-vars-in-bash-script.md)
@@ -1886,6 +1896,7 @@ See some of the other learning resources I work on:
 
 - [A Better Way To Reload ZSH Configuration](zsh/a-better-way-to-reload-zsh-configuration.md)
 - [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)
 - [Use A Space To Exclude Command From History](zsh/use-a-space-to-exclude-command-from-history.md)
 

aws/ssh-into-an-ecs-container.md

@@ -0,0 +1,50 @@
+# SSH Into An ECS Container
+
+In [Connect To Production Rails Console on AWS /
+Flightcontrol](https://www.visualmode.dev/connect-to-production-rails-console-aws-flightcontrol),
+I went into full detail about how to access `rails console` for a production
+Rails app running in an ECS container.
+
+A big part of that process was establishing an SSH connection to the ECS container.
+
+To do that, I need to know my region, container ID, and task ID. I can get the
+first two by listing my clusters and finding the cluster/container that houses
+the Rails app.
+
+```bash
+$ aws ecs list-clusters
+{
+    "clusterArns": [
+        "arn:aws:ecs:us-east-2:123:cluster/rails-app-abc123"
+    ]
+}
+```
+
+The region then is `us-east-2` and the container ID is `rails-app-abc123`.
+
+I can use that to find the task ID:
+
+```bash
+$ aws ecs list-tasks --region us-east-2 --cluster rails-app-abc123
+{
+    "taskArns": [
+        "arn:aws:ecs:us-east-2:123:task/rails-app-abc123/8526b3191d103bb1ff90c65a655ad004"
+    ]
+}
+```
+
+The task ID is the final portion of the URL:
+`8526b3191d103bb1ff90c65a655ad004`.
+
+Putting this all together I can SSH into the ECS container with a bash profile
+like so:
+
+```bash
+$ aws ecs execute-command \
+  --region us-east-2 \
+  --cluster rails-app-abc123 \
+  --container rails-app-abc123 \
+  --task 8526b3191d103bb1ff90c65a655ad004 \
+  --interactive \
+  --command "/bin/bash"
+```

aws/use-specific-aws-profile-with-cli.md

@@ -0,0 +1,37 @@
+# Use Specific AWS Profile With CLI
+
+I have multiple AWS profiles authenticated with the AWS CLI. For some projects
+I need to use the `default` one and for others I need to use the other.
+
+First, I can list the available profiles like so:
+
+```bash
+$ aws configure list-profiles
+default
+dev-my-app
+```
+
+For one-off commands I can specify the profile for any AWS CLI command using
+the `--profile` flag.
+
+```bash
+$ aws ecs list-clusters --profile josh-visualmode
+```
+
+However, I don't want to have to specify that flag every time when I'm working
+on a specific project. Instead I can specify the profile with an environment
+variable. The [`direnv`](https://direnv.net/) tool is a great way to do this on
+a per-project / per-directory basis.
+
+I can create or update the `.envrc` file (assuming I have `direnv` installed)
+adding the following line (and re-allowing the changed file):
+
+```
+# .envrc
+export AWS_PROFILE=dev-my-app
+```
+
+Now, any AWS command I issue from that directory or its subdirectories will use
+that profile by default.
+
+[source](https://docs.aws.amazon.com/cli/v1/userguide/cli-configure-files.html#cli-configure-files-using-profiles)

css/filter-blur-requires-expensive-calculation.md

@@ -0,0 +1,29 @@
+# Filter Blur Requires Expensive Calculation
+
+I had [a
+page](https://www.visualmode.dev/connect-to-production-rails-console-aws-flightcontrol)
+on my blog that was experiencing some odd rendering behavior. The issue was
+manifesting a couple ways.
+
+- Resizing and scrolling were janky and causing entire page layers to re-render
+causing the page to flash in and out.
+- Sometimes entire layer chunks would fail to paint leaving a white block
+missing from the page.
+
+The issue was occurring with and without JavaScript turned on for a
+statically-built page. I suspected that some aspect of the CSS was at fault.
+
+I was going back and forth with Dillon Hafer about what the issue could be and
+he wondered, "could it be the backdrop-blur class from tailwind?". I tried
+removing that class and the responsiveness of the page immediately improved.
+
+The [`filter:
+blur`](https://developer.mozilla.org/en-US/docs/Web/CSS/filter-function/blur)
+and [`backdrop-filter:
+blur`](https://developer.mozilla.org/en-US/docs/Web/CSS/backdrop-filter) both
+use an expensive [Gaussian blur](https://en.wikipedia.org/wiki/Gaussian_blur)
+calculation. One of these on a modern machine and browser probably won't have a
+noticable impact. However, a bunch of them, as in the case of my page with a
+recurring component, can have quite the performance hit.
+
+[source](https://github.com/tailwindlabs/tailwindcss/issues/15256)

javascript/accessing-arguments-to-a-function.md

@@ -5,6 +5,8 @@ an array-like object with all of the arguments to the function. Even if not
 all of the arguments are referenced in the function signature, they can
 still be accessed via the `arguments` object.
 
+> For ES6+ compatibility, the `spread` operator used via [rest parameters](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/rest_parameters) is preferred over the `arugments` object when accessing an abritrary number of function arguments.
+
 ```javascript
 function argTest(one) {
   console.log(one);

rails/adjust-the-production-log-level.md

@@ -0,0 +1,33 @@
+# Adjust The Production Log Level
+
+A Rails app by default takes on the `debug` log level. This is great for
+development because it spits out a lot of information as you build and debug.
+
+That's going to typically be a bit too noisy for a production environment
+though. That is why Rails ships with the `config/environments/production.rb`
+file configured to the `info` log level.
+
+```ruby
+# config/environments/production.rb
+Rails.application.configure do
+
+  # ...
+
+  # "info" includes generic and useful information about system operation, but avoids logging too much
+  # information to avoid inadvertent exposure of personally identifiable information (PII). If you
+  # want to log everything, set the level to "debug".
+  config.log_level = ENV.fetch("RAILS_LOG_LEVEL", "info")
+
+  # ...
+end
+```
+
+Sometimes, like when we're trying to track down some buggy behavior, we may
+want to switch Rails from one log level to another. That's why it is configured
+by the `RAILS_LOG_LEVEL` env var and otherwise falls back to `info`.
+
+To, for example, switch production over to the `debug` log level, we'd first
+change the `RAILS_LOG_LEVEL` env var to `debug`. Then we'd need to make sure
+our Rails app is restarted so that the config change is picked up. Heroku's
+`heroku config:set` will do that automatically. Depending on your setup, you
+may need to manually restart your web server (e.g. Puma).

rails/enforce-locals-passed-to-a-partial.md

@@ -0,0 +1,42 @@
+# Enforce Locals Passed To A Partial
+
+I have a big form partial (`_form.html.erb`) that is rendered by several
+different _new_ and _edit_ views. It's hard to tell at a glance, but the
+partial requires that `blogmark` and `cancel_path` are included as locals when
+it is rendered.
+
+As of [Rails 7.1](https://github.com/rails/rails/pull/45602), we now have a
+built-in way to enforce locals passed to a partial. We can add a magic comment
+at the top of the partial that specifies the locals:
+
+```ruby
+<%# locals: (blogmark:, cancel_path:) -%>
+<%= form_with(model: blogmark, local: true, class: "w-full max-w-3xl mb-8") do |form| %>
+  <% ... %>
+<% end  %>
+```
+
+This particular ERB magic comment declares that
+[`blogmark`](https://still.visualmode.dev/blogmarks) and `cancel_path` are
+required locals.
+
+So, what happens if I have a `new.html.erb` view that looks like this:
+
+```ruby
+<h1>New Blogmark</h1>
+
+<%= render 'blogmarks/form', blogmark: @blogmark %>
+```
+
+When I try to view the page, an error is raised:
+
+```
+Showing /Some/path/app/views/blogmarks/_form.html.erb where line # raised:
+
+missing local: :cancel_path for app/views/blogmarks/_form.html.erb
+```
+
+Updating the `render` statement to include a `cancel_path` local fixes the
+issue.
+
+[source](https://gorails.com/episodes/template-locals-in-rails-7-1)

unix/fix-previous-command-with-fc.md

@@ -0,0 +1,26 @@
+# Fix Previous Command With fc
+
+The `fc` command is a Bash and ZSH built-in command that allows you to interact
+with the history of commands issued in the shell. The most straightforward use
+case I know of for using this command is to fix or edit some aspect of the
+previous run command.
+
+When `fc` is executed with no arguments or flags, it will grab the latest entry
+to the command history and load it into your default editor. For me, that is
+Vim.
+
+I can make edits in that Vim session like I'd do in any other Vim session. When
+I write and quit (`:wq`) the file, the updated command will be executed. This
+is useful if, say, I've made a typo in the previous command and would prefer
+the ergonomics of my default editor to fix it. Or let's say I have a really
+long command with many flags and long file path arguments. It would be much
+easier and quicker to edit those paths from my editor than from the terminal
+prompt.
+
+If I've opened my editor (Vim) with `fc` and I decide I don't want to execute
+the command after all, I can _compiler quit_ Vim (exit with an error code)
+using `:cq`. The command will not be executed in this case.
+
+See `man zshbuiltins` for more details about this command and all of its flags.
+
+[source](https://www.computerhope.com/unix/uhistory.htm)

unix/list-the-pid-and-name-of-current-shell-process.md

@@ -0,0 +1,27 @@
+# List PID And Name Of Current Shell Process
+
+In Julia Evans' [How to add a directory to your
+PATH](https://jvns.ca/blog/2025/02/13/how-to-add-a-directory-to-your-path/),
+she shows off an odd-looking command for determining what shell (e.g. bash or
+zsh) you are currently running.
+
+```bash
+$ ps -p $$ -o pid=,comm=
+
+38105 -zsh
+```
+
+I already know I'm running `zsh`, but I thought this command was interesting
+enough to dig into and break down.
+
+- The `ps` command lists processes that "have controlling terminals"
+- The `$$` is a special shell variable representing the PID of the current process (try `echo $$`)
+- The `-p` flag allows you to specify a PID for `ps` to grab, in this case, the `$$` PID
+- The `-o` flag allows us to specify the output format, such as the PID and command name
+- The `=` after `pid` and `comm` tell `ps` to exclude headers from the output
+
+Additionally, I noticed that it output `-zsh` (not just `zsh`). That leading
+hyphen seems to indicate that [this `zsh` process is a _login
+shell_](https://unix.stackexchange.com/a/46856/5916). That means it was the
+process used to initiate an interactive shell session and something like the
+`.zprofile` would have been sourced as part of that.

zsh/create-and-jump-into-a-directory.md

@@ -0,0 +1,64 @@
+# Create And Jump Into A Directory
+
+[Oh My Zsh](https://github.com/ohmyzsh/ohmyzsh) defines a function `take` that
+we can use to both create and `cd` into a directory. If the directory already
+exists, it will simply `cd` into that directory.
+
+```bash
+~/code
+❯ take take-demo
+
+~/code/take-demo
+❯ mkdir already-exists
+
+~/code/take-demo
+❯ take already-exists
+
+~/code/take-demo/already-exists
+❯ cd ..
+
+~/code/take-demo
+❯ take one/two/three
+
+~/code/take-demo/one/two/three
+❯
+```
+
+First `take` creates and `cd`s into `take-demo`. Then `take` only `cd`s into
+`already-exists`. Then we see that `take` can create multiple levels of nested
+directories.
+
+With the help of `which` we can see how `take` is defined:
+
+```bash
+$ which take
+take () {
+        if [[ $1 =~ ^(https?|ftp).*\.tar\.(gz|bz2|xz)$ ]]
+        then
+                takeurl "$1"
+        elif [[ $1 =~ ^([A-Za-z0-9]\+@|https?|git|ssh|ftps?|rsync).*\.git/?$ ]]
+        then
+                takegit "$1"
+        else
+                takedir "$@"
+        fi
+}
+```
+
+We're not dealing with compressed files or git URLs, so we fall through to the
+`else` block with invokes `takedir`.
+
+```bash
+$ which takedir
+takedir () {
+        mkdir -p $@ && cd ${@:$#}
+}
+```
+
+The `mkdir -p $@` is what allows it make new, nested directories and then we
+`cd` to it. The `${@:$#}` is a way of [grabbing the last argument to the
+function](https://stackoverflow.com/a/37601842/535590). This suggests that you
+can pass multiple things to `take`, it will create all of them, and then `cd`
+you into the last one.
+
+[source](https://github.com/ohmyzsh/ohmyzsh/blob/master/lib/functions.zsh#L75-L85)