VSCode mix test task fails on fresh phx.new application

[awwong1]

Problem

The vscode-elixir-ls plugin debugger fails on a new phoenix application mix test task.

Reproduce

1. Create a new phoenix application

mix phx.new hello # accept when prompted
cd hello

2. Verify that mix test works in terminal

 mix test

# 13:12:05.053 [info]  Already up
# ...

# Finished in 0.07 seconds
# 3 tests, 0 failures

# Randomized with seed 130324

3. Verify that mix_test task fails in VS Code
   • .vscode/launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "mix_task",
            "name": "mix (Default task)",
            "request": "launch",
            "projectDir": "${workspaceRoot}"
        },
        {
            "type": "mix_task",
            "name": "mix test",
            "request": "launch",
            "task": "test",
            "taskArgs": [
                "--trace"
            ],
            "startApps": true,
            "projectDir": "${workspaceRoot}",
            "requireFiles": [
                "test/**/test_helper.exs",
                "test/**/*_test.exs"
            ]
        }
    ]
}

Started ElixirLS Fork debugger v0.3.1
Elixir version: "1.10.2 (compiled with Erlang/OTP 22)"
Erlang version: "22"
** Invalid beam file or no abstract code: 'Elixir.HelloWeb.PageControllerTest'
** Invalid beam file or no abstract code: 'Elixir.HelloWeb.ErrorViewTest'
** Invalid beam file or no abstract code: 'Elixir.HelloWeb.LayoutViewTest'
** Invalid beam file or no abstract code: 'Elixir.HelloWeb.PageViewTest'
(Debugger) Task failed because an exception was raised:
    ** (UndefinedFunctionError) function HelloWeb.PageViewTest.__ex_unit__/0 is undefined (module HelloWeb.PageViewTest is not available)
        HelloWeb.PageViewTest.__ex_unit__()
        (ex_unit 1.10.2) lib/ex_unit/runner.ex:118: ExUnit.Runner.run_module/2

Expected Behaviour

I expect the tests to execute in the same way as in the external terminal.

When I comment out all of the requireFiles, the task runs but I am unable to set breakpoints.

Environment

elixir -v  # Elixir version
# Erlang/OTP 22 [erts-10.6] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]
# Elixir 1.10.2 (compiled with Erlang/OTP 22)

mix phx # Phoenix version
# Phoenix v1.4.16

code -v # Microsoft Visual Studio Code version
# 1.43.0
# 78a4c91400152c0f27ba4d363eb56d2835f9903a
# x64

uname -srvmo # machine information
# Linux 4.19.0-8-amd64 #1 SMP Debian 4.19.98-1 (2020-01-26) x86_64 GNU/Linux

Name: ElixirLS Fork: Elixir support and debugger
Id: elixir-lsp.elixir-ls
Description: Elixir support with debugger, autocomplete, and more. Powered by ElixirLS.
Version: 0.3.1
Publisher: elixir-lsp
VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=elixir-lsp.elixir-ls

[bpiepiora]

I have the same issue with a normal 'mix new' application

Error output

Started ElixirLS Fork debugger v0.3.2
Elixir version: "1.10.2 (compiled with Erlang/OTP 22)"
Erlang version: "22"
** Invalid beam file or no abstract code: 'Elixir.BusinessRulesTest'
** Invalid beam file or no abstract code: 'Elixir.BusinessRulesTest'
(Debugger) Task failed because an exception was raised:
    ** (UndefinedFunctionError) function BusinessRulesTest.__ex_unit__/0 is undefined (module BusinessRulesTest is not available)
        BusinessRulesTest.__ex_unit__()
        (ex_unit 1.10.2) lib/ex_unit/runner.ex:118: ExUnit.Runner.run_module/2

22:22:36.444 [error] Process #PID<0.173.0> raised an exception
** (UndefinedFunctionError) function BusinessRulesTest.__ex_unit__/0 is undefined (module BusinessRulesTest is not available)
    BusinessRulesTest.__ex_unit__()
    (ex_unit 1.10.2) lib/ex_unit/runner.ex:118: ExUnit.Runner.run_module/2

Environment

elixir -v
# Erlang/OTP 22 [erts-10.7] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]
# Elixir 1.10.2 (compiled with Erlang/OTP 22)

code -v
# 1.43.2
# 0ba0ca52957102ca3527cf479571617f0de6ed50
# x64

uname --all
# Linux 5.5.11-200.fc31.x86_64 #1 SMP Mon Mar 23 17:32:43 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

[axelson]

I believe that we have to wait for Elixir 1.10.3 to be released so that it can contain this fix: elixir-lang/elixir#9864

As a workaround you can downgrade your project to 1.9.x.

[awwong1]

Sure, I will wait until 1.10.3 is released and then reproduce these steps. If they're still present, I will reopen this issue. Thanks!