From 4b9be76529b7a094172f721ea47ead7e9a34443c Mon Sep 17 00:00:00 2001
From: Lukasz Samson <lukaszsamson@gmail.com>
Date: Sun, 14 Jan 2024 21:45:38 +0100
Subject: [PATCH] add custom ExUnit formatter in debug adapter

return more test metadata
do not filter returned tests by `test` and `doctest` test_type
Fixes https://github.com/elixir-lsp/vscode-elixir-ls/issues/396
---
 .../lib/debug_adapter/exunit_formatter.ex     | 238 ++++++++++++++++++
 .../debug_adapter/lib/debug_adapter/output.ex |   4 +
 .../language_server/ex_unit_test_tracer.ex    |  60 +++--
 3 files changed, 276 insertions(+), 26 deletions(-)
 create mode 100644 apps/debug_adapter/lib/debug_adapter/exunit_formatter.ex

diff --git a/apps/debug_adapter/lib/debug_adapter/exunit_formatter.ex b/apps/debug_adapter/lib/debug_adapter/exunit_formatter.ex
new file mode 100644
index 000000000..7b45916a5
--- /dev/null
+++ b/apps/debug_adapter/lib/debug_adapter/exunit_formatter.ex
@@ -0,0 +1,238 @@
+defmodule ElixirLS.DebugAdapter.ExUnitFormatter do
+  use GenServer
+  alias ElixirLS.DebugAdapter.Output
+
+  @width 80
+
+  def start_link(args) do
+    GenServer.start_link(__MODULE__, Keyword.delete(args, :name),
+      name: Keyword.get(args, :name, __MODULE__)
+    )
+  end
+
+  @impl true
+  def init(_args) do
+    {:ok,
+     %{
+       failure_counter: 0
+     }}
+  end
+
+  @impl true
+  def terminate(reason, _state) do
+    case reason do
+      :normal ->
+        :ok
+
+      :shutdown ->
+        :ok
+
+      {:shutdown, _} ->
+        :ok
+
+      _other ->
+        message = Exception.format_exit(reason)
+
+        Output.telemetry(
+          "dap_server_error",
+          %{
+            "elixir_ls.dap_process" => inspect(__MODULE__),
+            "elixir_ls.dap_server_error" => message
+          },
+          %{}
+        )
+
+        Output.debugger_important("Terminating #{__MODULE__}: #{message}")
+    end
+
+    :ok
+  end
+
+  @impl true
+  def handle_cast({:suite_started, _opts}, state) do
+    # the suite has started with the specified options to the runner
+    # we don't need to do anything
+    {:noreply, state}
+  end
+
+  def handle_cast({:suite_finished, _times_us}, state) do
+    # the suite has finished. Returns several measurements in microseconds for running the suite
+    # not interesting
+    {:noreply, state}
+  end
+
+  def handle_cast({:module_started, %ExUnit.TestModule{}}, state) do
+    # a test module has started
+    # we report on individual tests
+    {:noreply, state}
+  end
+
+  def handle_cast({:module_finished, %ExUnit.TestModule{}}, state) do
+    # a test module has finished
+    # we report on individual tests
+    {:noreply, state}
+  end
+
+  def handle_cast({:test_started, test = %ExUnit.Test{}}, state) do
+    # a test has started
+    case test.state do
+      nil ->
+        # initial state
+        Output.ex_unit_event(%{
+          "event" => "test_started",
+          "type" => test.tags.test_type,
+          "name" => test_name(test),
+          "describe" => test.tags.describe,
+          "module" => inspect(test.module),
+          "file" => test.tags.file
+        })
+
+      {:skipped, _} ->
+        # Skipped via @tag :skip
+        Output.ex_unit_event(%{
+          "event" => "test_skipped",
+          "type" => test.tags.test_type,
+          "name" => test_name(test),
+          "describe" => test.tags.describe,
+          "module" => inspect(test.module),
+          "file" => test.tags.file
+        })
+
+      {:excluded, _} ->
+        # Excluded via :exclude filters
+        Output.ex_unit_event(%{
+          "event" => "test_excluded",
+          "type" => test.tags.test_type,
+          "name" => test_name(test),
+          "describe" => test.tags.describe,
+          "module" => inspect(test.module),
+          "file" => test.tags.file
+        })
+
+      _ ->
+        :ok
+    end
+
+    {:noreply, state}
+  end
+
+  def handle_cast({:test_finished, test = %ExUnit.Test{}}, state) do
+    # a test has finished
+    state =
+      case test.state do
+        nil ->
+          # Passed
+          Output.ex_unit_event(%{
+            "event" => "test_passed",
+            "type" => test.tags.test_type,
+            "time" => test.time,
+            "name" => test_name(test),
+            "describe" => test.tags.describe,
+            "module" => inspect(test.module),
+            "file" => test.tags.file
+          })
+
+          state
+
+        {:excluded, _} ->
+          # Excluded via :exclude filters
+          state
+
+        {:failed, failures} ->
+          # Failed
+          formatter_cb = fn _key, value -> value end
+
+          message =
+            ExUnit.Formatter.format_test_failure(
+              test,
+              failures,
+              state.failure_counter + 1,
+              @width,
+              formatter_cb
+            )
+
+          Output.ex_unit_event(%{
+            "event" => "test_failed",
+            "type" => test.tags.test_type,
+            "time" => test.time,
+            "name" => test_name(test),
+            "describe" => test.tags.describe,
+            "module" => inspect(test.module),
+            "file" => test.tags.file,
+            "message" => message
+          })
+
+          %{state | failure_counter: state.failure_counter + 1}
+
+        {:invalid, test_module = %ExUnit.TestModule{state: {:failed, failures}}} ->
+          # Invalid (when setup_all fails)
+          formatter_cb = fn _key, value -> value end
+
+          message =
+            ExUnit.Formatter.format_test_all_failure(
+              test_module,
+              failures,
+              state.failure_counter + 1,
+              @width,
+              formatter_cb
+            )
+
+          Output.ex_unit_event(%{
+            "event" => "test_errored",
+            "type" => test.tags.test_type,
+            "name" => test_name(test),
+            "describe" => test.tags.describe,
+            "module" => inspect(test.module),
+            "file" => test.tags.file,
+            "message" => message
+          })
+
+          %{state | failure_counter: state.failure_counter + 1}
+
+        {:skipped, _} ->
+          # Skipped via @tag :skip
+          state
+      end
+
+    {:noreply, state}
+  end
+
+  def handle_cast({:sigquit, _tests}, state) do
+    # the VM is going to shutdown. It receives the test cases (or test module in case of setup_all) still running
+    # we probably don't need to do anything
+    {:noreply, state}
+  end
+
+  def handle_cast(:max_failures_reached, state) do
+    # undocumented event - we probably don't need to do anything
+    {:noreply, state}
+  end
+
+  def handle_cast({:case_started, _test_case}, state) do
+    # deprecated event, ignore
+    # TODO remove when we require elixir 2.0
+    {:noreply, state}
+  end
+
+  def handle_cast({:case_finished, _test_case}, state) do
+    # deprecated event, ignore
+    # TODO remove when we require elixir 2.0
+    {:noreply, state}
+  end
+
+  # TODO extract to common module
+  defp test_name(test = %ExUnit.Test{}) do
+    describe = test.tags.describe
+    # drop test prefix
+    test_name = drop_test_prefix(test.name, test.tags.test_type)
+
+    if describe != nil do
+      test_name |> String.replace_prefix(describe <> " ", "")
+    else
+      test_name
+    end
+  end
+
+  defp drop_test_prefix(test_name, kind),
+    do: test_name |> Atom.to_string() |> String.replace_prefix(Atom.to_string(kind) <> " ", "")
+end
diff --git a/apps/debug_adapter/lib/debug_adapter/output.ex b/apps/debug_adapter/lib/debug_adapter/output.ex
index 63f5cc9ad..9984b4472 100644
--- a/apps/debug_adapter/lib/debug_adapter/output.ex
+++ b/apps/debug_adapter/lib/debug_adapter/output.ex
@@ -61,6 +61,10 @@ defmodule ElixirLS.DebugAdapter.Output do
     send_event(server, "output", %{"category" => "stderr", "output" => maybe_append_newline(str)})
   end
 
+  def ex_unit_event(server \\ __MODULE__, data) when is_map(data) do
+    send_event(server, "output", %{"category" => "ex_unit", "output" => "", "data" => data})
+  end
+
   def telemetry(server \\ __MODULE__, event, properties, measurements)
       when is_binary(event) and is_map(properties) and is_map(measurements) do
     elixir_release =
diff --git a/apps/language_server/lib/language_server/ex_unit_test_tracer.ex b/apps/language_server/lib/language_server/ex_unit_test_tracer.ex
index d968d5dcf..37c3523ce 100644
--- a/apps/language_server/lib/language_server/ex_unit_test_tracer.ex
+++ b/apps/language_server/lib/language_server/ex_unit_test_tracer.ex
@@ -113,14 +113,10 @@ defmodule ElixirLS.LanguageServer.ExUnitTestTracer do
         test_info
         |> Enum.group_by(fn %ExUnit.Test{tags: tags} -> {tags.describe, tags.describe_line} end)
         |> Enum.map(fn {{describe, describe_line}, tests} ->
-          grouped_tests = Enum.group_by(tests, fn %ExUnit.Test{tags: tags} -> tags.test_type end)
-
           tests =
-            grouped_tests
-            |> Map.get(:test, [])
-            |> Enum.map(fn %ExUnit.Test{tags: tags} = test ->
+            for %ExUnit.Test{tags: tags} = test <- tests do
               # drop test prefix
-              test_name = drop_test_prefix(test.name)
+              test_name = drop_test_prefix(test.name, tags.test_type)
 
               test_name =
                 if describe != nil do
@@ -129,26 +125,29 @@ defmodule ElixirLS.LanguageServer.ExUnitTestTracer do
                   test_name
                 end
 
+              selected_tags =
+                for {tag, value} <- tags, tag in [:async, :test_type, :doctest, :doctest_line] do
+                  "#{tag}:#{format_tag(tag, value)}"
+                end
+
+              doctest_module_path =
+                case tags[:doctest] do
+                  nil ->
+                    nil
+
+                  module ->
+                    if Code.ensure_loaded?(module) do
+                      to_string(module.module_info(:compile)[:source])
+                    end
+                end
+
               %{
                 name: test_name,
                 type: tags.test_type,
-                line: tags.line - 1
+                line: tags.line - 1,
+                doctest_module_path: doctest_module_path,
+                tags: selected_tags
               }
-            end)
-
-          tests =
-            case grouped_tests do
-              %{doctest: [doctest | _]} ->
-                test_meta = %{
-                  name: "doctest #{inspect(doctest.tags.doctest)}",
-                  line: doctest.tags.line - 1,
-                  type: :doctest
-                }
-
-                [test_meta | tests]
-
-              _ ->
-                tests
             end
 
           %{
@@ -168,9 +167,18 @@ defmodule ElixirLS.LanguageServer.ExUnitTestTracer do
     :ok
   end
 
-  defp drop_test_prefix(test_name) when is_atom(test_name),
-    do: test_name |> Atom.to_string() |> drop_test_prefix
+  defp drop_test_prefix(test_name, kind),
+    do: test_name |> Atom.to_string() |> String.replace_prefix(Atom.to_string(kind) <> " ", "")
+
+  defp format_tag(tag, value) when tag in [:doctest, :module] do
+    inspect(value)
+  end
 
-  defp drop_test_prefix("test " <> rest), do: rest
-  defp drop_test_prefix(test_name), do: test_name
+  defp format_tag(:doctest_line, value) do
+    to_string(value - 1)
+  end
+
+  defp format_tag(_tag, value) do
+    to_string(value)
+  end
 end