Migrate phoenix gen to igniter

[srikanthkyatham]

Contributor checklist

Atempt 1 to create PR. Once direction is right. I need to figure out how create tests. Perhaps embed a test project to generate the live views from it.

• Bug fixes include regression tests
• Features include unit/acceptance tests

[zachdaniel]

Extra comments.

[zachdaniel]

This looks great! TO test it, see how we do it in the igniter tests. You'd define a resource in test/support to use as the basis, and then do something like this:

import Igniter.Test

# in your test
test_project()
|> Igniter.compose_task("ash_phoenix.gen.live", [....])
|> assert_creates("....")

One challenge will be a dealing with the mix shell inputs, but there are tools for doing that
https://hexdocs.pm/mix/main/Mix.Shell.Process.html

IIRC you can send the answers to the prompts in order using this kind of code
send(self(), {:mix_shell_input, :prompt, "Pretty cool"})
and then when you run the task it will use those inputs.

One other thing worth noting is that there is an active PR to set up a phoenix project instead of just test_project(), in this PR:

ash-project/igniter#109

We can either wait on that or proceed without it. We can probably proceed without it.

[srikanthkyatham]

Cool I will write the tests and make the changes you pointed out. Yeah probably we can continue with out the other PR. Once it is merged I would be happy to contribute back.

[zachdaniel]

Great work, thank you!

[srikanthkyatham]

@zachdaniel

I figured the Mix shell prompts. Now I am stuck with the test_project setup

    igniter =
      assert test_project(
               files: %{
                 "lib/test/support.ex" => 
                 defmodule Test.Support do
                   use Ash.Domain

                   resources do
                     resource Test.Support.Ticket
                   end
                 end
                 )
                 |> apply_igniter!()
                 |> Igniter.compose_task("ash_phoenix.gen.live", [])

In the task, it is failing at

if !Spark.Dsl.is?(domain, Ash.Domain) do
It looks like I am missing sth. What are those is not quite evident. The tried dbg() the outputs. Not very helpful. Any pointers would be helpful.

[zachdaniel]

Right. So, the difficulty here is that those files are not compiled, and this task uses introspection to determine what to do.

This is a pretty hard problem TBH. I think we could add something like this to igniter (probably in test to start)

def compile(igniter) do
  igniter.rewrite
  |> Stream.map(fn source -> 
     Kernel.ParallelCompiler.async(fn -> 
       Code.compile_string(Rewrite.Source.get(source, :content))
     end)
  end)  
end

[srikanthkyatham]

Hi @zachdaniel

One other issue, I tried your compile function. It seems that

:erlang.get(:elixir_compiler_info)

is returning undefined. I have not played around Kernel.ParallelCompiler that much. Do you have any insight in this.
Basically the compilation is failing with following stacktrace

 code: |> compile()
     stacktrace:
       (elixir 1.17.3) lib/kernel/parallel_compiler.ex:53: Kernel.ParallelCompiler.inner_async/1
       (elixir 1.17.3) lib/kernel/parallel_compiler.ex:21: Kernel.ParallelCompiler.async/1
       (elixir 1.17.3) lib/stream.ex:613: anonymous fn/4 in Stream.map/2
       (elixir 1.17.3) lib/enum.ex:4858: Enumerable.List.reduce/3
       (elixir 1.17.3) lib/stream.ex:1891: Enumerable.Stream.do_each/4
       (elixir 1.17.3) lib/enum.ex:4423: Enum.reverse/1
       (elixir 1.17.3) lib/enum.ex:3746: Enum.to_list/1
       test/mix/tasks/ash_phoenix.gen.live_test.exs:152: Mix.Tasks.AshPhoenix.Gen.LiveTest.compile/1
       test/mix/tasks/ash_phoenix.gen.live_test.exs:117: (test)

[zachdaniel]

🤔 yeah, so that may not work. I think for now, for these tests, you will have to test with actually defined domains & resources. Like in the test/support folder.

[srikanthkyatham]

Hi

Ok I will try to create the resources in the test/support folder and continue with the tests.

[srikanthkyatham]

Hi @zachdaniel

Almost got it working. The last battle is with the indentation in the assert_creates

I have tried

1. Mix.Tasks.Format.formatter_for_file
2. Code.format_string!
3. String split on the code. I found you have used in one your tests.

The above is blocker now. I have pushed all my changes to the PR.

[srikanthkyatham]

Adding LiveView.Formatter helped a bit. Now there is a space at the end of file created

[srikanthkyatham]

All live gen test pass now. Please check and let me know how we can proceed.