Category: Note To Self

Two Ways of Solo Programming

Note To Self Pattern No Comments

Occasionally, especially in times between (paid) projects, I program solo. This morning, I realised that I operate in two ‘modes’ which slightly differ in the way I leave the project I’m working on in the evenings.

One way of working is when I program along while working through a book. Currently, I’m reading ‘Agile Web Development with Rails 7‘ (by Sam Ruby & Dave Thomas). I very much leave the ‘Depot’ app (the example application used in the book) with a completed section and passing tests. The Part of the next section is a fresh starting point in the following morning.

The other way is when I’m progressing in a project, i.e. a library or tool, I work on. In these cases, I prefer to leave a (read: one) failing test in the evening, so it’s easy to remember what I was planning to do in the morning: To fix/implement the code to make the tests pass. Note though, that I do not commit & push this failing tests to version control.

This is neither a new nor my idea. Nick Holden wrote about in 2018 already, in his blog post ‘Try ending today with a failing test for a great start tomorrow‘.

Have you noticed differences in developing software (whether it’s the coding, testing, UX, or any other aspect of it), between times of working alone versus working in a team? What are they? I would be seriously interested in hearing about this.

An Odd Behaviour When Creating A Rails App

Note To Self Rails Ruby 2 Comments

I’m currently looking into Rails 7 and found an odd behaviour when creating a new Rails app. Before creating a Rails app a few other things need to be in place, most notably Ruby, and _a_ database. My set up is this:

Ruby
3.1.0
Rails
7.0.2
rbenv
1.2.0
SQLite3
3.37.0
PostgreSQL
14.2

The simplest way to create a new Rails app is this:

rails new app_name

You can also specify various options, including, for example --css=tailwind, to use Tailwind for CSS. Since that’s what is used in a book I’m reading (‘Agile Web Development with Rails 7’ by Sam Ruby & Dave Thomas), I ran this:

rails new app_name --css=tailwind

Now I got an exception logged in the output, while also the exit code of the command was 0. Interesting. Here’s the command and the output (lots of output omitted for brevity):

rails new a_new_app --css=tailwind
      create
  …
      create  Gemfile
         run  git init from "."
Initialized empty Git repository in /Users/stephan/dev/tmp/a_new_app/.git/
      create  app
…
      create  config/master.key
      append  .gitignore
      create  config/boot.rb
…
      remove  config/initializers/new_framework_defaults_7_0.rb
         run  bundle install
Fetching gem metadata from https://rubygems.org/...........
Resolving dependencies....
Using rake 13.0.6
Using minitest 5.15.0

…
Using rails 7.0.2
Bundle complete! 16 Gemfile dependencies, 75 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.
         run  bundle binstubs bundler
       rails  importmap:install
…
Add Tailwindcss include tags and container element in application layout
      insert  app/views/layouts/application.html.erb
      insert  app/views/layouts/application.html.erb
      insert  app/views/layouts/application.html.erb
…
Add default Procfile.dev
      create  Procfile.dev
Ensure foreman is installed
         run  gem install foreman from "."
Successfully installed foreman-0.87.2
/Users/stephan/.rbenv/versions/3.1.0/lib/ruby/gems/3.1.0/gems/yard-0.9.27/lib/yard/rubygems/hook.rb:88:in `require': cannot load such file -- yard (LoadError)
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:88:in `load_yard'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:163:in `setup'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:152:in `generate'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:63:in `block in generation_hook'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:52:in `each'
  from ….rbenv/…/ruby/…/yard-0.9.27/lib/yard/rubygems/hook.rb:52:in `generation_hook'
  from ….rbenv/…/ruby/…/request_set.rb:311:in `block in install_hooks'
  from ….rbenv/…/ruby/…/request_set.rb:310:in `each'
  from ….rbenv/…/ruby/…/request_set.rb:310:in `install_hooks'
  from ….rbenv/…/ruby/…/request_set.rb:209:in `install'
  from ….rbenv/…/ruby/…/commands/install_command.rb:210:in `install_gem'
  from ….rbenv/…/ruby/…/commands/install_command.rb:226:in `block in install_gems'
  from ….rbenv/…/ruby/…/commands/install_command.rb:219:in `each'
  from ….rbenv/…/ruby/…/commands/install_command.rb:219:in `install_gems'
  from ….rbenv/…/ruby/…/commands/install_command.rb:167:in `execute'
  from ….rbenv/…/ruby/…/command.rb:323:in `invoke_with_build_args'
  from ….rbenv/…/ruby/…/command_manager.rb:180:in `process_args'
  from ….rbenv/…/ruby/…/command_manager.rb:149:in `run'
  from ….rbenv/…/ruby/…/gem_runner.rb:53:in `run'
  from ….rbenv/versions/3.1.0/bin/gem:13:in `<main>'
Add bin/dev to start foreman
      create  bin/dev
Compile initial Tailwind build
         run  rails tailwindcss:build from "."
+ /Users/stephan/.rbenv/versions/3.1.0/lib/ruby/gems/3.1.0/gems/tailwindcss-rails-2.0.5-x86_64-darwin/exe/x86_64-darwin/tailwindcss -i /Users/stephan/dev/tmp/a_new_app/app/assets/stylesheets/application.tailwind.css -o /Users/stephan/dev/tmp/a_new_app/app/assets/builds/tailwind.css -c /Users/stephan/dev/tmp/a_new_app/config/tailwind.config.js

Done in 228ms.

This is … interesting, since yard is found, when listing matching gems:

> gem list yard

*** LOCAL GEMS ***

yard (0.9.27)

However, the command that is running at this time is (apparently) executed in the context of Bundler. Since yard isn’t listed in the Gemfile, Bundler won’t find or use it:

bundle info yard
Could not find gem 'yard'.

After uninstalling yard, creating a new Rails app works fine and doesn’t log an exception.

While this solves the issue of getting the exception, it was still unclear why this happened in the first place.

Now, what is yard?

YARD is a documentation generation tool for the Ruby programming language.

https://github.com/lsegal/yard

Aha, looking into my .gemrc (which is used to configure Rubygems), I found these two lines (Yes, I like to have the documentation generated 🙂):

install: --rdoc --ri --document=yri
update: --rdoc --ri --document=yri

After removing the --document=yri, creating a new Rails app worked fine even with yard being installed.

I still don’t completely understand, why this is an issue when specifying a CSS processor, but not otherwise. This may be topic for another post.
If you have an idea about why this happens, please let me know.

The Different Ways of Pry and Irb

Learning Note To Self Ruby shell No Comments

I ran into an interesting little problem when doing sone Ruby (and Rails) work today: I wanted to try something in pry and, inside that Rails project I issued the following command:

$ pry -r sqlite3
…/gems/pry-0.14.1/lib/pry/pry_class.rb:103:in `require': cannot load such file -- sqlite3 (LoadError)
  from …/gems/pry-0.14.1/lib/pry/pry_class.rb:103:in `block in load_requires'
  from …/gems/pry-0.14.1/lib/pry/pry_class.rb:102:in `each'
  from …/gems/pry-0.14.1/lib/pry/pry_class.rb:102:in `load_requires'
  from …/gems/pry-0.14.1/lib/pry/pry_class.rb:143:in `final_session_setup'
  from …/gems/pry-0.14.1/lib/pry/cli.rb:82:in `parse_options'
  from …/gems/pry-0.14.1/bin/pry:12:in `<top (required)>'
  from …/bin/pry:23:in `load'
  from …/bin/pry:23:in `<main>'
  from …/bin/ruby_executable_hooks:22:in `eval'
  from …/bin/ruby_executable_hooks:22:in `<main>'

Interesting! I have both gems, pry and sqlite3 installed. A similar attempt using irb worked fine:

$ irb -r sqlite3
3.0.1 :001 > SQLite3::VERSION
 => "1.4.2"
3.0.1 :002 >

Maybe I confused the environment by setting some environment variable or other? With a newly opened command shell I got this:

$ pry -r sqlite3
[1] pry(main)> SQLite3::VERSION
=> "1.4.2"
[2] pry(main)>

Remarkable. In that new shell the irb command behaved the same as before.

The only difference I could find was that the original call to pry happened in a Rails project – which is using Bundler to organise the Rubygems used in the project and resolve dependencies. As a small experiment I set up a minimal project that uses bundler and a rather short Gemfile:

source "https://rubygems.org"

gem  'limit_detectors'

The gem ‘limit_detectors’ is one I wrote and I know that is doesn’t depend on other gems. Issuing the pry command again … worked? Why? Some more investigation was needed…

Finally, I realised that another gem (Guard, to be specific), uses pry. Therefore my Rails project’s development environment indirectly depends on pry. It looks like pry recognises that it’s running as part of a Bundler project, even when it is not explicitly called using bundle exec pry …, which in turn causes it (pry) to ‘only’ recognise the gems that are also installed using Bundler. – And sqlite3 isn’t in this case, since I’m using PostgreSQL throughout.

Since irb comes with the Ruby installation and is not part of the bundled gems, it ignores the bundler context when called like this:

irb -r sqlite3

However, explicitly calling it in the bundler context in a project that doesn’t depend on ‘sqlite3’ (directly or indirectly) will cause an error message:

$ bundle exec irb -r sqlite3
…/rubies/ruby-3.0.1/lib/ruby/3.0.0/irb/init.rb:376: warning: LoadError: cannot load such file -- sqlite3
3.0.1 :001 >

Nice! This is essentially the same problem, I faced at the very beginning, when pry couldn’t find the sqlite3 gem.

A Local Rails Server in a Local Network

Note To Self Rails Ruby No Comments

I’m currently working on a Rails app, that I want to have available in my local network on the default port that Ruby on Rails uses: 3000.

To do that, I added a line to the development config (config/environments/development.rb):

config.hosts << 'hostname.local'

Update: Apparently adding the line config.hosts.clear works as well. Details about this are explained in the Rails Guides.

I started using Foreman to achieve this, and installed it using:

gem install foreman

Note that, according to a Wiki Page on Github, it’s not recommended to put foreman into the Gemfile.

Then I created a Procfile that Foreman uses to start the web server (which currently is the only process I need it to start):

web: bundle exec rails s -b 0.0.0.0 -p 3000

The -b 0.0.0.0 binds the process to that IP address and -p 3000 instructs it to use port 3000.

With that set up foreman start can be used to start a Rails server in development which is available in the local network.

This way I can check the layout and functionality on a mobile phone or one of my iPads.

Seeing And Saying On The Command Line

Note To Self Tools for Testing No Comments

Occasionally I like command line tools to also say the output, in addition to ‘printing’ it (to STDOUT).

A current context is starting a server locally with updated information. The start up takes time, so I tend to not wait at the command line for it to fully boot.

I wanted a noticeable signal when the thing is up – and also a confirmation that the version of the information source *is* actually updated. The commands tee and (the macOS) say do this for me:

tee >(say&)

tee copies the output of its input to STDOUT (usually the terminal) and the given file. The construction >(other command&) causes tee to send the input not to a file but to othercommand and the & causes that command to return immediately (instead of returning only after the command to finish).

Overall, I do something like this. The system returns a lengthy JSON string, so I use jq to get to the version information I’m looking for:

curl -s -u <username:thepassword> “<url_to_locally_running_service>” | jq “<path_to_version_info_in_json>” | tee >(say&)

The GitHub page explains that

jq is a lightweight and flexible command-line JSON processor.

https://stedolan.github.io/jq/

It’s well worth trying, if you’re dealing with JSON input on the command line.

Passing Multiple Arguments To One Rake Task

Note To Self shell No Comments

Occasionally, I want Rake tasks to take multiple arguments. If the number of these arguments are know beforehand, Rake provides a nice way to express that in the Rakefile (see the Rake documentation for more details).

However, sometimes I like to pass a varying number of arguments the a task, which shall all be processed in the same way. Maybe its user IDs that need to be removed from a database, or a given list of piles to be processed.

Today I found a way to do this, by using Rake::TaskArguments#extras . The method extras returns a list of all the extra arguments passed to a Rake task, that are not named in the task definition. If no argument name(s) are declared in the task definition, then all arguments will be ‘extra arguments’.

An example Rakefile is this:

task :list do |t, args|
  puts "In task '#{t.name}"
  puts 'Passed arguments:'
  puts args.extras.map { |extra| "  * #{extra}" }
end

Calling this task from the command line and its output (in zsh) looks like this:

$ rake list\[one,2,3.141]
In task 'list
Passed arguments:
  * one
  * 2
  * 3.141

Note, the \ before the opening bracket ‘[‘. In zsh, this is needed to escape the ‘[‘ (pairs of ‘[]’ have a special meaning in zsh). Also note, that there are no spaces between the arguments, just the comma.

If you prefer to add a space after the comma, there’s a way to achieve this (again in zsh): Drop the ‘\’ and instead put the task name and the arguments in quotes:

$ rake "list[one, 2, 3.141]"
In task 'list
Passed arguments:
  * one
  * 2
  * 3.141

$ rake 'list[one, 2, 42]'
In task 'list
Passed arguments:
  * one
  * 2
  * 42

In this example it doesn’t affect the output whether single or double quotes are used. Quoting in shells is … complicated, see for example: http://zsh.sourceforge.net/Guide/zshguide05.html#l112.

Did you find this helpful? Or do you know a better way to pass multiple arguments to one Rake task? Please let me know.


A Quick Way To Sort Text on macOS

Note To Self 2 Comments

One way to quickly sort text on macOS that I’m currently using is this:

I copy the text (Mark text & CMD-C) and them do this in iTerm:

pbpaste | sort | pbcopy

And that’s it, already. The text is sorted and copied back to the clip board.

Update: this small change fits my actual needs even better: Sort the input case-insensitive:

pbpaste | sort -f | pbcopy

And as an Alfred App user I can even do this (and don’t have to open a terminal):

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