fix(engine): only start one engine for umbrella apps

apps/forge/lib/forge/project.ex

@@ -413,26 +413,52 @@ defmodule Forge.Project do
     end
   end
 
+  @doc """
+  Returns the `apps_path` configured in `mix.exs` when `project_path` is an
+  umbrella root, otherwise returns `nil`.
+  """
+  def umbrella_apps_path(project_path) when is_binary(project_path) do
+    mix_exs_path = Path.join(project_path, "mix.exs")
+
+    with true <- File.exists?(mix_exs_path),
+         {:ok, source} <- File.read(mix_exs_path),
+         {:ok, ast} <- Code.string_to_quoted(source),
+         apps_path when is_binary(apps_path) <- extract_apps_path(ast) do
+      apps_path
+    else
+      _ -> nil
+    end
+  end
+
   def find_parent_root_dir(path) do
     path = Forge.Document.Path.from_uri(path)
-    path = path |> Path.expand() |> Path.dirname()
+    path = path |> Path.expand() |> path_or_parent_dir()
+    boundary = workspace_boundary_path()
 
     segments = Path.split(path)
 
-    traverse_path(segments)
+    case traverse_path(segments, boundary) do
+      nil -> nil
+      root -> Document.Path.to_uri(root)
+    end
   end
 
-  defp traverse_path([]), do: nil
+  defp traverse_path([], _boundary), do: nil
 
-  defp traverse_path(segments) do
+  defp traverse_path(segments, boundary) do
     path = Path.join(segments)
     mix_exs_path = Path.join(path, "mix.exs")
 
-    if File.exists?(mix_exs_path) do
-      Document.Path.to_uri(path)
-    else
-      {_, rest} = List.pop_at(segments, -1)
-      traverse_path(rest)
+    cond do
+      boundary_reached?(path, boundary) ->
+        nil
+
+      File.exists?(mix_exs_path) ->
+        umbrella_root_for(path, boundary) || path
+
+      true ->
+        {_, rest} = List.pop_at(segments, -1)
+        traverse_path(rest, boundary)
     end
   end
 
@@ -446,4 +472,78 @@ defmodule Forge.Project do
       :ok
     end
   end
+
+  defp workspace_boundary_path do
+    case Forge.Workspace.get_workspace() do
+      %Forge.Workspace{root_path: root_path} when is_binary(root_path) ->
+        Path.expand(root_path)
+
+      _ ->
+        nil
+    end
+  end
+
+  defp boundary_reached?(_path, nil), do: false
+
+  defp boundary_reached?(path, boundary) do
+    expanded_path = Path.expand(path)
+
+    not Forge.Path.parent_path?(expanded_path, boundary)
+  end
+
+  defp path_or_parent_dir(path) do
+    if File.dir?(path) do
+      path
+    else
+      Path.dirname(path)
+    end
+  end
+
+  defp umbrella_root_for(project_path, boundary) do
+    project_path = Path.expand(project_path)
+    do_find_umbrella_root(Path.dirname(project_path), project_path, boundary)
+  end
+
+  defp do_find_umbrella_root(current_path, project_path, boundary) do
+    if !boundary_reached?(current_path, boundary) do
+      case umbrella_apps_path(current_path) do
+        apps_path when is_binary(apps_path) ->
+          apps_root = Path.expand(Path.join(current_path, apps_path))
+
+          if project_path == apps_root or Forge.Path.parent_path?(project_path, apps_root) do
+            current_path
+          else
+            next_parent(current_path, project_path, boundary)
+          end
+
+        _ ->
+          next_parent(current_path, project_path, boundary)
+      end
+    end
+  end
+
+  defp next_parent(current_path, project_path, boundary) do
+    parent = Path.dirname(current_path)
+
+    cond do
+      parent == current_path ->
+        nil
+
+      boundary_reached?(parent, boundary) ->
+        nil
+
+      true ->
+        do_find_umbrella_root(parent, project_path, boundary)
+    end
+  end
+
+  defp extract_apps_path(ast) do
+    {_ast, apps_path} =
+      Macro.prewalk(ast, nil, fn
+        {:apps_path, value} = node, nil when is_binary(value) -> {node, value}
+        node, acc -> {node, acc}
+      end)
+
+    apps_path
+  end
 end

apps/forge/test/fixtures/umbrella/packages/search/lib/search.ex

@@ -0,0 +1,2 @@
+defmodule Search do
+end

apps/forge/test/fixtures/umbrella/packages/search/mix.exs

@@ -0,0 +1,12 @@
+defmodule Search.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :search,
+      version: "0.1.0",
+      elixir: "~> 1.15",
+      deps: []
+    ]
+  end
+end

apps/forge/test/fixtures/umbrella_custom_apps_path/mix.exs

@@ -0,0 +1,11 @@
+defmodule UmbrellaCustomAppsPath.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      apps_path: "packages",
+      version: "0.1.0",
+      deps: []
+    ]
+  end
+end

apps/forge/test/fixtures/umbrella_custom_apps_path/packages/first/lib/first.ex

@@ -0,0 +1,2 @@
+defmodule UmbrellaCustomAppsPath.First do
+end

apps/forge/test/fixtures/umbrella_custom_apps_path/packages/first/mix.exs

@@ -0,0 +1,12 @@
+defmodule UmbrellaCustomAppsPath.First.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :first,
+      version: "0.1.0",
+      elixir: "~> 1.15",
+      deps: []
+    ]
+  end
+end

apps/forge/test/forge/project_umbrella_test.exs

@@ -0,0 +1,149 @@
+defmodule Forge.ProjectUmbrellaTest do
+  use ExUnit.Case, async: true
+
+  import Forge.Test.Fixtures
+
+  alias Forge.Document
+  alias Forge.Project
+  alias Forge.Workspace
+
+  defp umbrella_root, do: Path.join(fixtures_path(), "umbrella")
+  defp sub_app_path(name), do: Path.join([umbrella_root(), "apps", name])
+  defp package_project_path(name), do: Path.join([umbrella_root(), "packages", name])
+  defp custom_umbrella_root, do: Path.join(fixtures_path(), "umbrella_custom_apps_path")
+  defp custom_sub_app_path(name), do: Path.join([custom_umbrella_root(), "packages", name])
+
+  setup do
+    Workspace.set_workspace(nil)
+
+    on_exit(fn ->
+      Workspace.set_workspace(nil)
+    end)
+
+    :ok
+  end
+
+  describe "umbrella_apps_path/1" do
+    test "returns apps_path for an umbrella project" do
+      assert Project.umbrella_apps_path(umbrella_root()) == "apps"
+    end
+
+    test "returns nil for a sub-app directory" do
+      assert Project.umbrella_apps_path(sub_app_path("first")) == nil
+    end
+
+    test "returns nil for a directory without mix.exs" do
+      assert Project.umbrella_apps_path(Path.join(fixtures_path(), "nonexistent")) == nil
+    end
+
+    test "returns nil for a non-umbrella project" do
+      project_path = Path.join(fixtures_path(), "project")
+
+      if File.exists?(Path.join(project_path, "mix.exs")) do
+        assert Project.umbrella_apps_path(project_path) == nil
+      end
+    end
+
+    test "returns custom apps_path for an umbrella project" do
+      assert Project.umbrella_apps_path(custom_umbrella_root()) == "packages"
+    end
+  end
+
+  describe "find_parent_root_dir/1 with umbrella projects" do
+    test "returns umbrella root URI for a file inside a sub-app" do
+      file_uri = Document.Path.to_uri(Path.join(sub_app_path("first"), "lib/first.ex"))
+      result = Project.find_parent_root_dir(file_uri)
+
+      expected = Document.Path.to_uri(umbrella_root())
+      assert result == expected
+    end
+
+    test "returns umbrella root URI for a file in sub-app with same name as umbrella" do
+      file_uri = Document.Path.to_uri(Path.join(sub_app_path("umbrella"), "lib/umbrella.ex"))
+      result = Project.find_parent_root_dir(file_uri)
+
+      expected = Document.Path.to_uri(umbrella_root())
+      assert result == expected
+    end
+
+    test "returns umbrella root URI for sub-app mix.exs" do
+      file_uri = Document.Path.to_uri(Path.join(sub_app_path("second"), "mix.exs"))
+      result = Project.find_parent_root_dir(file_uri)
+
+      expected = Document.Path.to_uri(umbrella_root())
+      assert result == expected
+    end
+
+    test "returns non-umbrella package root URI for a file outside apps_path" do
+      file_uri = Document.Path.to_uri(Path.join(package_project_path("search"), "lib/search.ex"))
+      result = Project.find_parent_root_dir(file_uri)
+
+      expected = Document.Path.to_uri(package_project_path("search"))
+      assert result == expected
+    end
+
+    test "returns umbrella root URI when apps_path is set to a custom directory" do
+      file_uri = Document.Path.to_uri(Path.join(custom_sub_app_path("first"), "lib/first.ex"))
+      result = Project.find_parent_root_dir(file_uri)
+
+      expected = Document.Path.to_uri(custom_umbrella_root())
+      assert result == expected
+    end
+
+    test "returns normal project root for non-umbrella projects" do
+      project_path = Path.join(fixtures_path(), "project")
+
+      if File.exists?(Path.join(project_path, "mix.exs")) do
+        file_uri = Document.Path.to_uri(Path.join(project_path, "lib/project.ex"))
+        result = Project.find_parent_root_dir(file_uri)
+
+        expected = Document.Path.to_uri(project_path)
+        assert result == expected
+      end
+    end
+
+    test "does not traverse above workspace root while detecting umbrella root" do
+      Workspace.set_workspace(Workspace.new(sub_app_path("first")))
+
+      file_uri = Document.Path.to_uri(Path.join(sub_app_path("first"), "lib/first.ex"))
+      result = Project.find_parent_root_dir(file_uri)
+
+      expected = Document.Path.to_uri(sub_app_path("first"))
+      assert result == expected
+    end
+  end
+
+  describe "find_project/1 with umbrella projects" do
+    test "returns project rooted at umbrella root for sub-app files" do
+      file_uri = Document.Path.to_uri(Path.join(sub_app_path("first"), "lib/first.ex"))
+      project = Project.find_project(file_uri)
+
+      expected_root = Document.Path.to_uri(umbrella_root())
+      assert project.root_uri == expected_root
+    end
+
+    test "returns project rooted at umbrella root for sub-app with same name" do
+      file_uri = Document.Path.to_uri(Path.join(sub_app_path("umbrella"), "lib/umbrella.ex"))
+      project = Project.find_project(file_uri)
+
+      expected_root = Document.Path.to_uri(umbrella_root())
+      assert project.root_uri == expected_root
+    end
+
+    test "returns project rooted at a non-umbrella package outside apps_path" do
+      file_uri = Document.Path.to_uri(Path.join(package_project_path("search"), "lib/search.ex"))
+      project = Project.find_project(file_uri)
+
+      expected_root = Document.Path.to_uri(package_project_path("search"))
+      assert project.root_uri == expected_root
+    end
+
+    test "returns project rooted at umbrella root when apps_path is custom" do
+      file_uri = Document.Path.to_uri(Path.join(custom_sub_app_path("first"), "lib/first.ex"))
+      project = Project.find_project(file_uri)
+
+      expected_root = Document.Path.to_uri(custom_umbrella_root())
+      assert project.root_uri == expected_root
+    end
+  end
+end