feat: workspace folders

apps/expert/config/runtime.exs

@@ -20,5 +20,3 @@ if Code.ensure_loaded?(LoggerFileBackend) do
 else
   :ok
 end
-
-require Logger

apps/expert/lib/expert.ex

@@ -14,6 +14,7 @@ defmodule Expert do
     GenLSP.Notifications.TextDocumentDidChange,
     GenLSP.Notifications.WorkspaceDidChangeConfiguration,
     GenLSP.Notifications.WorkspaceDidChangeWatchedFiles,
+    GenLSP.Notifications.WorkspaceDidChangeWorkspaceFolders,
     GenLSP.Notifications.TextDocumentDidClose,
     GenLSP.Notifications.TextDocumentDidOpen,
     GenLSP.Notifications.TextDocumentDidSave,
@@ -112,6 +113,7 @@ defmodule Expert do
   end
 
   def handle_notification(%GenLSP.Notifications.Initialized{}, lsp) do
+    Logger.info("Server initialized, registering capabilities")
     registrations = registrations()
 
     if nil != GenLSP.request(lsp, registrations) do

apps/expert/lib/expert/active_projects.ex

@@ -0,0 +1,50 @@
+defmodule Expert.ActiveProjects do
+  @moduledoc """
+  A cache to keep track of active projects.
+
+  Since GenLSP events happen asynchronously, we use an ets table to keep track of
+  them and avoid race conditions when we try to update the list of active projects.
+  """
+
+  use GenServer
+
+  def child_spec(_) do
+    %{
+      id: __MODULE__,
+      start: {__MODULE__, :start_link, []}
+    }
+  end
+
+  def start_link do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  def init(_) do
+    __MODULE__ = :ets.new(__MODULE__, [:set, :named_table, :public, read_concurrency: true])
+    {:ok, nil}
+  end
+
+  def projects do
+    __MODULE__
+    |> :ets.tab2list()
+    |> Enum.map(fn {_, project} -> project end)
+  end
+
+  def add_projects(new_projects) when is_list(new_projects) do
+    for new_project <- new_projects do
+      # We use `:ets.insert_new/2` to avoid overwriting the cached project's entropy
+      :ets.insert_new(__MODULE__, {new_project.root_uri, new_project})
+    end
+  end
+
+  def remove_projects(removed_projects) when is_list(removed_projects) do
+    for removed_project <- removed_projects do
+      :ets.delete(__MODULE__, removed_project.root_uri)
+    end
+  end
+
+  def set_projects(new_projects) when is_list(new_projects) do
+    :ets.delete_all_objects(__MODULE__)
+    add_projects(new_projects)
+  end
+end

apps/expert/lib/expert/application.ex

@@ -18,6 +18,7 @@ defmodule Expert.Application do
       {GenLSP.Assigns, [name: Expert.Assigns]},
       {Task.Supervisor, name: :expert_task_queue},
       {GenLSP.Buffer, name: Expert.Buffer},
+      {Expert.ActiveProjects, []},
       {Expert,
        buffer: Expert.Buffer,
        task_supervisor: :expert_task_queue,

apps/expert/lib/expert/configuration.ex

@@ -6,19 +6,16 @@ defmodule Expert.Configuration do
   alias Expert.Configuration.Support
   alias Expert.Dialyzer
   alias Expert.Protocol.Id
-  alias Forge.Project
   alias GenLSP.Notifications.WorkspaceDidChangeConfiguration
   alias GenLSP.Requests
   alias GenLSP.Structures
 
-  defstruct project: nil,
-            support: nil,
+  defstruct support: nil,
             client_name: nil,
             additional_watched_extensions: nil,
             dialyzer_enabled?: false
 
   @type t :: %__MODULE__{
-          project: Project.t() | nil,
           support: support | nil,
           client_name: String.t() | nil,
           additional_watched_extensions: [String.t()] | nil,
@@ -29,12 +26,11 @@ 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
+  @spec new(Structures.ClientCapabilities.t(), String.t() | nil) :: t
+  def new(%Structures.ClientCapabilities{} = client_capabilities, client_name) do
     support = Support.new(client_capabilities)
-    project = Project.new(root_uri)
 
-    %__MODULE__{support: support, project: project, client_name: client_name}
+    %__MODULE__{support: support, client_name: client_name}
     |> tap(&set/1)
   end
 

apps/expert/lib/expert/engine_supervisor.ex

@@ -14,11 +14,15 @@ defmodule Expert.EngineSupervisor do
   end
 
   def start_link(%Project{} = project) do
-    DynamicSupervisor.start_link(__MODULE__, project, name: __MODULE__, strategy: :one_for_one)
+    DynamicSupervisor.start_link(__MODULE__, project, name: name(project), strategy: :one_for_one)
+  end
+
+  defp name(%Project{} = project) do
+    :"#{Project.name(project)}::project_node_supervisor"
   end
 
   def start_project_node(%Project{} = project) do
-    DynamicSupervisor.start_child(__MODULE__, EngineNode.child_spec(project))
+    DynamicSupervisor.start_child(name(project), EngineNode.child_spec(project))
   end
 
   @impl true

apps/expert/lib/expert/project/supervisor.ex

@@ -7,16 +7,6 @@ defmodule Expert.Project.Supervisor do
   alias Expert.Project.SearchListener
   alias Forge.Project
 
-  # TODO: this module is slightly weird
-  # it is a module based supervisor, but has lots of dynamic supervisor functions
-  # what I learned is that in Expert.Application, it is starting an ad hoc
-  # dynamic supervisor, calling a function from this module
-  # Later, when the server is initializing, it calls the start function in
-  # this module, which starts a normal supervisor, which the start_link and
-  # init callbacks will be called
-  # my suggestion is to separate the dynamic supervisor functionalities from
-  # this module into its own module
-
   use Supervisor
 
   def start_link(%Project{} = project) do
@@ -49,7 +39,7 @@ defmodule Expert.Project.Supervisor do
     DynamicSupervisor.terminate_child(Expert.Project.DynamicSupervisor.name(), pid)
   end
 
-  defp name(%Project{} = project) do
+  def name(%Project{} = project) do
     :"#{Project.name(project)}::supervisor"
   end
 end

apps/expert/lib/expert/provider/handlers/code_action.ex

@@ -1,20 +1,24 @@
 defmodule Expert.Provider.Handlers.CodeAction do
+  alias Expert.ActiveProjects
   alias Expert.Configuration
   alias Expert.EngineApi
   alias Forge.CodeAction
+  alias Forge.Project
   alias GenLSP.Requests
   alias GenLSP.Structures
 
   def handle(
         %Requests.TextDocumentCodeAction{params: %Structures.CodeActionParams{} = params},
-        %Configuration{} = config
+        %Configuration{}
       ) do
     document = Forge.Document.Container.context_document(params, nil)
+    projects = ActiveProjects.projects()
+    project = Project.project_for_document(projects, document)
     diagnostics = Enum.map(params.context.diagnostics, &to_code_action_diagnostic/1)
 
     code_actions =
       EngineApi.code_actions(
-        config.project,
+        project,
         document,
         params.range,
         diagnostics,

apps/expert/lib/expert/provider/handlers/code_lens.ex

@@ -1,4 +1,5 @@
 defmodule Expert.Provider.Handlers.CodeLens do
+  alias Expert.ActiveProjects
   alias Expert.Configuration
   alias Expert.EngineApi
   alias Expert.Provider.Handlers
@@ -14,12 +15,16 @@ defmodule Expert.Provider.Handlers.CodeLens do
 
   def handle(
         %Requests.TextDocumentCodeLens{params: %Structures.CodeLensParams{} = params},
-        %Configuration{} = config
+        %Configuration{}
       ) do
     document = Document.Container.context_document(params, nil)
+    projects = ActiveProjects.projects()
+    project = Project.project_for_document(projects, document)
+
+    document = Document.Container.context_document(params, nil)
 
     lenses =
-      case reindex_lens(config.project, document) do
+      case reindex_lens(project, document) do
         nil -> []
         lens -> List.wrap(lens)
       end

apps/expert/lib/expert/provider/handlers/commands.ex

@@ -1,4 +1,5 @@
 defmodule Expert.Provider.Handlers.Commands do
+  alias Expert.ActiveProjects
   alias Expert.Configuration
   alias Expert.EngineApi
   alias Forge.Project
@@ -25,13 +26,16 @@ defmodule Expert.Provider.Handlers.Commands do
 
   def handle(
         %Requests.WorkspaceExecuteCommand{params: %Structures.ExecuteCommandParams{} = params},
-        %Configuration{} = config
+        %Configuration{}
       ) do
+    projects = ActiveProjects.projects()
+
     response =
       case params.command do
         @reindex_name ->
-          Logger.info("Reindex #{Project.name(config.project)}")
-          reindex(config.project)
+          project_names = Enum.map_join(projects, ", ", &Project.name/1)
+          Logger.info("Reindex #{project_names}")
+          reindex_all(projects)
 
         invalid ->
           message = "#{invalid} is not a valid command"
@@ -41,23 +45,25 @@ defmodule Expert.Provider.Handlers.Commands do
     {:reply, response}
   end
 
-  defp reindex(%Project{} = project) do
-    case EngineApi.reindex(project) do
-      :ok ->
-        {:ok, "ok"}
+  defp reindex_all(projects) do
+    Enum.reduce_while(projects, :ok, fn project, _ ->
+      case EngineApi.reindex(project) do
+        :ok ->
+          {:cont, "ok"}
 
-      error ->
-        GenLSP.notify(Expert.get_lsp(), %GenLSP.Notifications.WindowShowMessage{
-          params: %GenLSP.Structures.ShowMessageParams{
-            type: GenLSP.Enumerations.MessageType.error(),
-            message: "Indexing #{Project.name(project)} failed"
-          }
-        })
+        error ->
+          GenLSP.notify(Expert.get_lsp(), %GenLSP.Notifications.WindowShowMessage{
+            params: %GenLSP.Structures.ShowMessageParams{
+              type: GenLSP.Enumerations.MessageType.error(),
+              message: "Indexing #{Project.name(project)} failed"
+            }
+          })
 
-        Logger.error("Indexing command failed due to #{inspect(error)}")
+          Logger.error("Indexing command failed due to #{inspect(error)}")
 
-        {:ok, internal_error("Could not reindex: #{error}")}
-    end
+          {:halt, internal_error("Could not reindex: #{error}")}
+      end
+    end)
   end
 
   defp internal_error(message) do

apps/expert/lib/expert/provider/handlers/completion.ex

@@ -1,9 +1,11 @@
 defmodule Expert.Provider.Handlers.Completion do
+  alias Expert.ActiveProjects
   alias Expert.CodeIntelligence
   alias Expert.Configuration
   alias Forge.Ast
   alias Forge.Document
   alias Forge.Document.Position
+  alias Forge.Project
   alias GenLSP.Enumerations.CompletionTriggerKind
   alias GenLSP.Requests
   alias GenLSP.Structures
@@ -13,13 +15,15 @@ defmodule Expert.Provider.Handlers.Completion do
         %Requests.TextDocumentCompletion{
           params: %Structures.CompletionParams{} = params
         },
-        %Configuration{} = config
+        %Configuration{}
       ) do
     document = Document.Container.context_document(params, nil)
+    projects = ActiveProjects.projects()
+    project = Project.project_for_document(projects, document)
 
     completions =
       CodeIntelligence.Completion.complete(
-        config.project,
+        project,
         document_analysis(document, params.position),
         params.position,
         params.context || %CompletionContext{trigger_kind: CompletionTriggerKind.invoked()}

apps/expert/lib/expert/provider/handlers/document_symbols.ex

@@ -1,17 +1,21 @@
 defmodule Expert.Provider.Handlers.DocumentSymbols do
+  alias Expert.ActiveProjects
   alias Expert.Configuration
   alias Expert.EngineApi
   alias Forge.CodeIntelligence.Symbols
   alias Forge.Document
+  alias Forge.Project
   alias GenLSP.Enumerations.SymbolKind
   alias GenLSP.Requests
   alias GenLSP.Structures
 
-  def handle(%Requests.TextDocumentDocumentSymbol{} = request, %Configuration{} = config) do
+  def handle(%Requests.TextDocumentDocumentSymbol{} = request, %Configuration{}) do
     document = Document.Container.context_document(request.params, nil)
+    projects = ActiveProjects.projects()
+    project = Project.project_for_document(projects, document)
 
     symbols =
-      config.project
+      project
       |> EngineApi.document_symbols(document)
       |> Enum.map(&to_response(&1, document))
 

apps/expert/lib/expert/provider/handlers/find_references.ex

@@ -1,24 +1,28 @@
 defmodule Expert.Provider.Handlers.FindReferences do
+  alias Expert.ActiveProjects
   alias Expert.Configuration
   alias Expert.EngineApi
   alias Forge.Ast
   alias Forge.Document
+  alias Forge.Project
   alias GenLSP.Requests.TextDocumentReferences
   alias GenLSP.Structures
 
   require Logger
 
   def handle(
         %TextDocumentReferences{params: %Structures.ReferenceParams{} = params},
-        %Configuration{} = config
+        %Configuration{}
       ) do
     document = Forge.Document.Container.context_document(params, nil)
+    projects = ActiveProjects.projects()
+    project = Project.project_for_document(projects, document)
     include_declaration? = !!params.context.include_declaration
 
     locations =
       case Document.Store.fetch(document.uri, :analysis) do
         {:ok, _document, %Ast.Analysis{} = analysis} ->
-          EngineApi.references(config.project, analysis, params.position, include_declaration?)
+          EngineApi.references(project, analysis, params.position, include_declaration?)
 
         _ ->
           nil

apps/expert/lib/expert/provider/handlers/formatting.ex

@@ -1,19 +1,23 @@
 defmodule Expert.Provider.Handlers.Formatting do
+  alias Expert.ActiveProjects
   alias Expert.Configuration
   alias Expert.EngineApi
   alias Forge.Document.Changes
+  alias Forge.Project
   alias GenLSP.Requests
   alias GenLSP.Structures
 
   require Logger
 
   def handle(
         %Requests.TextDocumentFormatting{params: %Structures.DocumentFormattingParams{} = params},
-        %Configuration{} = config
+        %Configuration{}
       ) do
     document = Forge.Document.Container.context_document(params, nil)
+    projects = ActiveProjects.projects()
+    project = Project.project_for_document(projects, document)
 
-    case EngineApi.format(config.project, document) do
+    case EngineApi.format(project, document) do
       {:ok, %Changes{} = document_edits} ->
         {:ok, document_edits}