Improve intellisense modules handling (#2745)

lib/livebook/intellisense.ex

@@ -24,9 +24,38 @@ defmodule Livebook.Intellisense do
           map_binding: (Code.binding() -> any())
         }
 
+  @doc """
+  Adjusts the system for more accurate intellisense.
+  """
+  @spec load() :: :ok
+  def load() do
+    # Completion looks for modules in loaded applications, so we ensure
+    # that the most relevant built-in applications are loaded
+    apps = [:erts, :crypto, :inets, :public_key, :runtime_tools, :ex_unit, :iex]
+
+    for app <- apps do
+      Application.load(app)
+    end
+
+    :ok
+  end
+
+  @doc """
+  Clears all cache stored by the intellisense modules.
+  """
+  @spec clear_cache() :: :ok
+  def clear_cache() do
+    for node <- Node.list() do
+      clear_cache(node)
+    end
+
+    :ok
+  end
+
   @doc """
   Clear any cache stored related to the given node.
   """
+  @spec clear_cache(node()) :: :ok
   def clear_cache(node) do
     IdentifierMatcher.clear_all_loaded(node)
   end

lib/livebook/runtime/erl_dist/node_manager.ex

@@ -146,6 +146,10 @@ defmodule Livebook.Runtime.ErlDist.NodeManager do
       Code.prepend_path(ebin_path)
     end
 
+    Livebook.Intellisense.load()
+
+    :net_kernel.monitor_nodes(true, node_type: :all)
+
     {:ok,
      %{
        unload_modules_on_termination: unload_modules_on_termination,
@@ -163,6 +167,8 @@ defmodule Livebook.Runtime.ErlDist.NodeManager do
 
   @impl true
   def terminate(_reason, state) do
+    Livebook.Intellisense.clear_cache()
+
     Code.compiler_options(ignore_module_conflict: state.initial_ignore_module_conflict)
 
     if ansi_syntax_colors = state.initial_ansi_syntax_colors do
@@ -238,6 +244,11 @@ defmodule Livebook.Runtime.ErlDist.NodeManager do
     {:noreply, state}
   end
 
+  def handle_info({:nodedown, node, _metadata}, state) do
+    Livebook.Intellisense.clear_cache(node)
+    {:noreply, state}
+  end
+
   def handle_info(_message, state), do: {:noreply, state}
 
   defp make_tmp_dir() do

lib/livebook/runtime/erl_dist/runtime_server.ex

@@ -335,7 +335,7 @@ defmodule Livebook.Runtime.ErlDist.RuntimeServer do
   @impl true
   def init(opts) do
     Process.send_after(self(), :check_owner, @await_owner_timeout)
-    :net_kernel.monitor_nodes(true, node_type: :all)
+
     schedule_memory_usage_report()
 
     {:ok, evaluator_supervisor} = ErlDist.EvaluatorSupervisor.start_link()
@@ -383,11 +383,6 @@ defmodule Livebook.Runtime.ErlDist.RuntimeServer do
     end
   end
 
-  def handle_info({:nodedown, node, _metadata}, state) do
-    Livebook.Intellisense.clear_cache(node)
-    {:noreply, state}
-  end
-
   def handle_info({:DOWN, _, :process, owner, _}, %{owner: owner} = state) do
     {:stop, :shutdown, state}
   end

test/test_helper.exs

@@ -6,9 +6,6 @@ Livebook.Runtime.ErlDist.NodeManager.start(
   unload_modules_on_termination: false
 )
 
-# We load erts so we can access its modules for completion.
-Application.load(:erts)
-
 # Use the embedded runtime in tests by default, so they are cheaper
 # to run. Other runtimes can be tested by setting them explicitly
 Application.put_env(:livebook, :default_runtime, Livebook.Runtime.Embedded.new())