Support filtering mix deps output

[rhcarvalho]

Makes it easier to report versions of specific dependencies by allowing users (or tools) to pass dependency names as arguments to mix deps.

Warns when a dependency is not found, similar to mix deps.unlock.

Proposal: https://groups.google.com/g/elixir-lang-core/c/5tlLZ1yu4rQ/m/g7Z8fNWiBwAJ

[josevalim]

Suggested change

[rhcarvalho]

My chance to ask about an official stance on code style w.r.t. extra trailing empty lines on @moduledoc and @doc :)

I never found an explanation for that and find both styles and Elixir, Phoenix and other high profile projects.

Several tasks have a @moduledoc that has that extra empty line, and that includes the current implementation of deps.ex:

elixir/lib/mix/lib/mix/tasks/deps.ex

Lines 185 to 189 in b60e424

	It supports the following options:
	* `--all` - lists all dependencies, regardless of specified environment
	"""

What's the thought process here? Is it add extra line after a bullet list, indented block, and/or something else?!

I looked through all the files under mix/tasks/ and bullet/block seems like the pattern, except for a few files that seem to be inconsistent with that:

• elixir/lib/mix/lib/mix/tasks/archive.uninstall.ex

  Lines 15 to 18 in b60e424

  	## Command line options
  	* `--force` - forces uninstallation without a shell prompt; primarily
  	intended for automation
  	"""

• elixir/lib/mix/lib/mix/tasks/escript.uninstall.ex

  Lines 15 to 18 in b60e424

  	## Command line options
  	* `--force` - forces uninstallation without a shell prompt; primarily
  	intended for automation
  	"""

• elixir/lib/mix/lib/mix/tasks/release.init.ex

  Lines 10 to 18 in b60e424

  	@moduledoc """
  	Generates sample files for releases.
  	$ mix release.init
  	* creating rel/vm.args.eex
  	* creating rel/remote.vm.args.eex
  	* creating rel/env.sh.eex
  	* creating rel/env.bat.eex
  	"""

If I inferred the pattern right, couldn't that be something that mix format takes care for us?

I'm sure missing nuance and historical context! Eager to learn.

[josevalim]

I don’t think j it matters much but you nailed it: no empty lines except at the end of lists.

[rhcarvalho]

• Updated implementation to use @josevalim's suggestion based on Enum.flat_map/2 and Enum.find/2
• Added input deduplication test
• Revised documentation
• Reverted to branch using explicit if (cases of defp action_or_different_action helpers are rare in the codebase)

[josevalim]

You can use Process.info(self(), :messages) to get all messages, and then pattern matching on the list. It should lead to a cleaner test, I will rewrite that after merging!

[rhcarvalho]

I tried to borrow from other tests, e.g.

elixir/lib/mix/test/mix/tasks/xref_test.exs

Lines 1338 to 1344 in bd909cb

	defp receive_until_no_messages(acc) do
	receive do
	{:mix_shell, :info, [line]} -> receive_until_no_messages([acc, line | "\n"])
	after
	0 -> IO.iodata_to_binary(acc)
	end
	end

In case you want to look at them as a greater whole when rewriting!

Thanks for the review rounds! 💜

[josevalim]

💚 💙 💜 💛 ❤️