Start projects dynamically

Author: doorgan

apps/expert/lib/expert/configuration.ex

@@ -30,11 +30,10 @@ defmodule Expert.Configuration do
   @dialyzer {:nowarn_function, set_dialyzer_enabled: 2}
 
   @spec new(Forge.uri(), map(), String.t() | nil) :: t
-  def new(root_uri, %Structures.ClientCapabilities{} = client_capabilities, client_name) do
+  def new(_root_uri, %Structures.ClientCapabilities{} = client_capabilities, client_name) do
     support = Support.new(client_capabilities)
-    projects = find_projects(root_uri)
 
-    %__MODULE__{support: support, projects: projects, client_name: client_name}
+    %__MODULE__{support: support, projects: [], client_name: client_name}
     |> tap(&set/1)
   end
 
@@ -43,34 +42,6 @@ defmodule Expert.Configuration do
     struct!(__MODULE__, [support: Support.new()] ++ attrs)
   end
 
-  defp find_projects(root_uri) do
-    root_path = Forge.Document.Path.from_uri(root_uri)
-    root_mix_exs = Path.join(root_path, "mix.exs")
-
-    projects =
-      if File.exists?(root_mix_exs) do
-        [Project.new(root_uri)]
-      else
-        find_multiroot_projects(root_path)
-      end
-
-    if projects == [], do: [Project.new(root_uri)], else: projects
-  end
-
-  defp find_multiroot_projects(root_path) do
-    mix_exs_blob = Path.join([root_path, "**", "mix.exs"])
-
-    for mix_exs_path <- Path.wildcard(mix_exs_blob),
-        "deps" not in Path.split(mix_exs_path) do
-      project_uri =
-        mix_exs_path
-        |> Path.dirname()
-        |> Forge.Document.Path.to_uri()
-
-      Project.new(project_uri)
-    end
-  end
-
   defp set(%__MODULE__{} = config) do
     :persistent_term.put(__MODULE__, config)
   end
@@ -168,4 +139,18 @@ defmodule Expert.Configuration do
   defp maybe_add_watched_extensions(%__MODULE__{} = old_config, _) do
     {:ok, old_config}
   end
+
+  @spec add_project(t, Project.t()) :: t
+  def add_project(%__MODULE__{} = config, %Project{} = project) do
+    if Enum.any?(config.projects, &(&1.root_uri == project.root_uri)) do
+      config
+    else
+      projects = [project | config.projects]
+      new_config = %__MODULE__{config | projects: projects}
+
+      set(new_config)
+
+      new_config
+    end
+  end
 end

apps/expert/lib/expert/state.ex

@@ -66,19 +66,29 @@ defmodule Expert.State do
 
     Transport.write(registrations())
 
-    for project <- config.projects do
-      Logger.info("Starting project at uri #{project.root_uri}")
-      result = Expert.Project.Supervisor.start(project)
-      Logger.info("result: #{inspect(result)}")
-    end
-
     {:ok, new_state}
   end
 
   def initialize(%__MODULE__{initialized?: true}, %Requests.Initialize{}) do
     {:error, :already_initialized}
   end
 
+  defp maybe_start_project(project, config) do
+    already_started? =
+      Enum.any?(config.projects, fn p ->
+        p.root_uri == project.root_uri
+      end)
+
+    if already_started? do
+      :ok
+    else
+      Logger.info("Starting project at uri #{project.root_uri}")
+      result = Expert.Project.Supervisor.start(project)
+      Logger.info("result: #{inspect(result)}")
+      :ok
+    end
+  end
+
   def in_flight?(%__MODULE__{} = state, request_id) do
     Map.has_key?(state.in_flight_requests, request_id)
   end
@@ -180,6 +190,18 @@ defmodule Expert.State do
       language_id: language_id
     } = did_open.params.text_document
 
+    project = Project.find_project(uri)
+    config = state.configuration
+
+    state =
+      if not is_nil(project) do
+        maybe_start_project(project, config)
+        config = Configuration.add_project(config, project)
+        %__MODULE__{state | configuration: config}
+      else
+        state
+      end
+
     case Document.Store.open(uri, text, version, language_id) do
       :ok ->
         Logger.info("opened #{uri}")

apps/forge/lib/forge/project.ex

@@ -341,4 +341,37 @@ defmodule Forge.Project do
       Forge.Path.parent_path?(document.path, root_path(project))
     end)
   end
+
+  def find_project(path) do
+    project_root = find_parent_root_dir(path)
+
+    if is_nil(project_root) do
+      nil
+    else
+      new(project_root)
+    end
+  end
+
+  defp find_parent_root_dir(path) do
+    path = Forge.Document.Path.from_uri(path)
+    path = path |> Path.expand() |> Path.dirname()
+
+    segments = Path.split(path)
+
+    traverse_path(segments)
+  end
+
+  defp traverse_path([]), do: nil
+
+  defp traverse_path(segments) 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)
+    end
+  end
 end