Add generators

[crertel]

This PR is about adding mix scenic.gen.scene and mix scenic.gen.component helpers.

It's currently a work in progress, but if this is looking like a good idea we can wrap it up.

Current questions are:

• How to we get the proper base module name, e.g. MyApp in MyApp.Scenes.SceneName when we've run mix scenic.gen.scene scene_name?
• Are there additional considerations around umbrella apps or whatever?

[Eiji7]

How to we get the proper base module name, e.g. MyApp in MyApp.Scenes.SceneName when we've run mix scenic.gen.scene scene_name?

Simply look how Phoenix core team solves it … I recommend to read especially Mix.Phoenix code.

Here you have app module name:
https://github.com/phoenixframework/phoenix/blob/e05af0ad5527c9a192de122f3e43d7ed4c7a4c9f/lib/mix/phoenix.ex#L123-L150

Here you have web path:
https://github.com/phoenixframework/phoenix/blob/e05af0ad5527c9a192de122f3e43d7ed4c7a4c9f/lib/mix/phoenix.ex#L196-L204

Are there additional considerations around umbrella apps or whatever?

https://github.com/phoenixframework/phoenix/blob/e05af0ad5527c9a192de122f3e43d7ed4c7a4c9f/lib/mix/tasks/phx.gen.schema.ex#L102-L104

Short: don't complicate and simply raise 😈

If you really want you can add app name option.

[crertel]

@Eiji7 went ahead and added that, and made some common helpers based on the Phoenix approach.

It'd still be cool to get some feedback from @boydm on this spike. :)

[crertel]

Thanks for looking over this with me @Eiji7 !

One bothersome detail is that the tests are failing for the gen.scenic.scene, because I don't think we're autodetecting the root module quite correctly. I've hit my spare cycles for this for today, but am open to ideas.

[Eiji7]

@crertel One bothersome detail is that the tests are failing for the gen.scenic.scene, because I don't think we're autodetecting the root module quite correctly. I've hit my spare cycles for this for today, but am open to ideas.

You have 2 options:

1. Don't change generated app name (phoenix also checks for PhoenixWeb module name)
2. Change configuration like:

Application.put_env(String.to_atom(@app_name), :namespace, String.to_atom(@module_name))

[Eiji7]

If you apply above suggestions to lib/mix/tasks/scenic.gen.component.ex and lib/mix/tasks/scenic.gen.scene.ex and then call mix format everything should be ok.

[Eiji7]

Before merge we would need a simple cleanup:

1. Minimal callback documentation like @impl Scenic.Component (as said rest could be added later, but this is must have)
2. Apply changes to pass mix format checks on Travis (already described above)
3. Remove IO.inspect/1 call (added for debugging)
4. Remove commented tests code or remove comments and update tests
5. Following phoenix task file name should be task.name.ex for example: lib/mix/tasks/scenic.gen.component.ex
   see: https://github.com/phoenixframework/phoenix/tree/master/lib/mix/tasks
6. Keep same file/directory structure in lib and test

lib/mix/tasks/scenic_gen_component.ex -> lib/mix/tasks/scenic.gen.component.exs
test/scenic_gen_component_test.exs -> test/mix/tasks/scenic.gen.component_test.exs

[Eiji7]

It would be nice if you could add 2 extra changes:

  def tmp_path do
    Path.expand("../tmp", __DIR__)
  end

  # …

  def in_tmp(which, function) do
    path = Path.join([tmp_path(), random_string(10), to_string(which)])

    try do
      File.rm_rf!(path)
      File.mkdir_p!(path)
      File.cd!(path, function)
    after
      path |> Path.dirname() |> File.rm_rf!()
    end
  end

The first in tmp_path/0 returns path to tmp dir in root project directory instead of parent directory which does not makes sense.

Secondly path |> Path.dirname() |> File.rm_rf!() removes not only Path.join([tmp_path(), random_string(10), to_string(which)]), but also Path.join([tmp_path(), random_string(10)]). That way we would not have many empty directories in tmp directory.

[Eiji7]

Regarding tests here goes for scene:

  @scene_module "TestScene"
  @scene_name "test_scene"

  test "gen.scene" do
    in_project("new with defaults", "my_app", fn _mix_project ->
      output = capture_io(fn -> Mix.Tasks.Scenic.Gen.Scene.run([@scene_module]) end)
      module_definition = "defmodule MyApp.Scene.#{@scene_module} do"
      assert_file("lib/scenes/#{@scene_name}.ex", module_definition)
      assert output =~ "Created scene #{@scene_module}."
    end)
  end

  test "gen.scene inside umbrella" do
    in_project("umbrella", "my_umbrella", ["--umbrella"], Mix.Tasks.New, fn _mix_project ->
      func = fn -> Mix.Tasks.Scenic.Gen.Scene.run([]) end
      assert_raise Mix.Error, func
    end)
  end

  test "gen.scene with app" do
    in_project("new with app", "my_app", ["--module", "My.App"], fn _mix_project ->
      args = [@scene_module, "--app", "My.App"]
      output = capture_io(fn -> Mix.Tasks.Scenic.Gen.Scene.run(args) end)
      assert output =~ "Created scene #{@scene_module}."
      module_definition = "defmodule My.App.Scene.#{@scene_module} do"
      assert_file("lib/scenes/#{@scene_name}.ex", module_definition)
    end)
  end

  test "gen.scene without args displays help" do
    in_project("help", "help", fn _mix_project ->
      output1 = capture_io(fn -> Mix.Tasks.Scenic.Gen.Scene.run([]) end)
      output2 = capture_io(fn -> Mix.Tasks.Help.run(["scenic.gen.scene"]) end)
      assert output1 == output2
    end)
  end

  defp in_project(tmp_dir, app_name, extra_args \\ [], task \\ Mix.Tasks.Scenic.New, project_func) do
    in_tmp(tmp_dir, fn ->
      capture_io(fn -> task.run([app_name | extra_args]) end)
      app_name |> String.to_atom() |> Mix.Project.in_project(app_name, project_func)
    end)
  end

[Eiji7]

And for component:

  @component_module "TestComponent"
  @component_name "test_component"

  test "gen.component" do
    in_project("new with defaults", "my_app", fn _mix_project ->
      output = capture_io(fn -> Mix.Tasks.Scenic.Gen.Component.run([@component_module]) end)
      module_definition = "defmodule MyApp.Component.#{@component_module} do"
      assert_file("lib/components/#{@component_name}.ex", module_definition)
      assert output =~ "Created component #{@component_module}."
    end)
  end

  test "gen.component inside umbrella" do
    in_project("umbrella", "my_umbrella", ["--umbrella"], Mix.Tasks.New, fn _mix_project ->
      func = fn -> Mix.Tasks.Scenic.Gen.Component.run([]) end
      assert_raise Mix.Error, func
    end)
  end

  test "gen.component with app" do
    in_project("new with app", "my_app", ["--module", "My.App"], fn _mix_project ->
      args = [@component_module, "--app", "My.App"]
      output = capture_io(fn -> Mix.Tasks.Scenic.Gen.Component.run(args) end)
      assert output =~ "Created component #{@component_module}."
      module_definition = "defmodule My.App.Component.#{@component_module} do"
      assert_file("lib/components/#{@component_name}.ex", module_definition)
    end)
  end

  test "gen.component without args displays help" do
    in_project("help", "help", fn _mix_project ->
      output1 = capture_io(fn -> Mix.Tasks.Scenic.Gen.Component.run([]) end)
      output2 = capture_io(fn -> Mix.Tasks.Help.run(["scenic.gen.component"]) end)
      assert output1 == output2
    end)
  end

  defp in_project(tmp_dir, app_name, extra_args \\ [], task \\ Mix.Tasks.Scenic.New, project_func) do
    in_tmp(tmp_dir, fn ->
      capture_io(fn -> task.run([app_name | extra_args]) end)
      app_name |> String.to_atom() |> Mix.Project.in_project(app_name, project_func)
    end)
  end

Look that in_project/5 is same for both, so should go to mix_helper.exs.

Those changes should satisfy codecov.

[crertel]

Okay, that should get us into a happier spot.

[Eiji7]

After that remove WIP part from title as it would be ready to merge.

[crertel]

Okiedokie, let's get @boydm to take a look.

[crertel]

Broughtt in the awesome work @axelson did!

[Eiji7]

@crertel This code is unfortunately invalid now as v0.11 branch was deleted after merging PR. I guess we should mark it WIP until new scenic release, then change scenic version to latest from hex and finally mark it as ready to merge.

[crertel]

I'm doing cleanup right now, and switched us over to the hex v0.11 RC. More on the way.

[crertel]

@boydm Should be ready for proper consideration now!

[crertel]

Talked to Boyd today; we're going to move the generators over to single-file mix tasks in core scenic (and swap the templates for heredocs), and then move @axelson 's work here for 0.11 support into normal scenic_new.

[axelson]

Sounds good 👍
Thanks for bringing in my changes!

[boydm]

Talked to Cretel. The generators are better off in the main scenic tasks and should not go into scenic_new.

@axelson, sorry but I've done a bunch of work to scenic_new and now I'm thinking it would be too hard to merge your changes in. Take a look at the current version and lets talk if there are things you want to do to it.