From f4685d01266b4afb7f557d9a361fc7770aa22ec6 Mon Sep 17 00:00:00 2001
From: Mitchell Hanberg <mitch@mitchellhanberg.com>
Date: Wed, 15 May 2024 10:06:15 -0400
Subject: [PATCH] fix: ensure some elixir internals are ready (#478)

Frequently we'd see the following error in tests, and some users were
seeing in production:

```
[error] Bad RPC call to node nextls-runtime-1715431446385794000@MacBook
-XXX: {:EXIT, {:badarg, [{:ets, :lookup, [:elixir_config,
:parser_options], [error_info: %{cause: :id, module: :erl_stdlib_errors}]
}, {:elixir_config, :get, 1, [file: ~c"src/elixir_config.erl", line: 21]}
, {:elixir_compiler, :string, 3, [file: ~c"src/elixir_compiler.erl", line
: 7]}, {Module.ParallelChecker, :verify, 1, [file: ~c"lib/module/parallel
_checker.ex", line: 112]}, {Code, :compile_file, 1, []}]}}
```

I believe that this is caused by an internal ETS table not being booted
yet, so we not await on it being present on the project node.

Closes #467
---
 .github/workflows/release.yaml           | 24 +++++-----
 lib/next_ls/runtime.ex                   | 56 +++++++++++++++++-------
 priv/monkey/_next_ls_private_compiler.ex |  8 ++--
 3 files changed, 55 insertions(+), 33 deletions(-)

diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 49102ae6..3aa8f98e 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -9,22 +9,22 @@ permissions:
   pull-requests: write
 
 jobs:
-  commitlint:
-    runs-on: ubuntu-latest
-    name: commitlint
+  # commitlint:
+  #   runs-on: ubuntu-latest
+  #   name: commitlint
 
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - name: Install Deps
-        run: yarn install
-      - name: Lint PR Title
-        run: yarn commitlint --from "${{ github.event.before }}"
+  #   steps:
+  #     - uses: actions/checkout@v4
+  #       with:
+  #         fetch-depth: 0
+  #     - name: Install Deps
+  #       run: yarn install
+  #     - name: Lint PR Title
+  #       run: yarn commitlint --from "${{ github.event.before }}"
 
   release:
     name: release
-    needs: commitlint
+    # needs: commitlint
     runs-on: ubuntu-latest
     outputs:
       release_created: ${{ steps.release.outputs.release_created }}
diff --git a/lib/next_ls/runtime.ex b/lib/next_ls/runtime.ex
index 4ca68420..749122d6 100644
--- a/lib/next_ls/runtime.ex
+++ b/lib/next_ls/runtime.ex
@@ -231,22 +231,32 @@ defmodule NextLS.Runtime do
              true <- connect(node, port, 120) do
           NextLS.Logger.info(logger, "Connected to node #{node}")
 
-          :next_ls
-          |> :code.priv_dir()
-          |> Path.join("monkey/_next_ls_private_compiler.ex")
-          |> then(&:rpc.call(node, Code, :compile_file, [&1]))
-          |> tap(fn
-            {:badrpc, error} ->
-              NextLS.Logger.error(logger, "Bad RPC call to node #{node}: #{inspect(error)}")
-              send(me, {:cancel, error})
-
-            _ ->
-              :ok
-          end)
-
-          {:ok, _} = :rpc.call(node, :_next_ls_private_compiler, :start, [])
-
-          send(me, {:node, node})
+          result =
+            :next_ls
+            |> :code.priv_dir()
+            |> Path.join("monkey/_next_ls_private_compiler.ex")
+            |> then(fn path ->
+              if await_config_table(node, 5) do
+                :rpc.call(node, Code, :compile_file, [path])
+              else
+                {:badrpc, "internal ets table not found"}
+              end
+            end)
+            |> then(fn
+              {:badrpc, error} ->
+                NextLS.Logger.error(logger, "Bad RPC call to node #{node}: #{inspect(error)}")
+                send(me, {:cancel, error})
+                :error
+
+              _ ->
+                :ok
+            end)
+
+          if result == :ok do
+            {:ok, _} = :rpc.call(node, :_next_ls_private_compiler, :start, [])
+
+            send(me, {:node, node})
+          end
         else
           error ->
             send(me, {:cancel, error})
@@ -275,6 +285,20 @@ defmodule NextLS.Runtime do
     end
   end
 
+  defp await_config_table(_node, 0) do
+    false
+  end
+
+  defp await_config_table(node, attempts) do
+    # this is an Elixir implementation detail, handle with care
+    if :undefined == :rpc.call(node, :ets, :whereis, [:elixir_config]) do
+      Process.sleep(100)
+      await_config_table(node, attempts - 1)
+    else
+      true
+    end
+  end
+
   @impl GenServer
   def handle_call(:ready?, _from, state) when is_ready(state) do
     {:reply, true, state}
diff --git a/priv/monkey/_next_ls_private_compiler.ex b/priv/monkey/_next_ls_private_compiler.ex
index 3e34a6b1..d673b3ea 100644
--- a/priv/monkey/_next_ls_private_compiler.ex
+++ b/priv/monkey/_next_ls_private_compiler.ex
@@ -1032,14 +1032,13 @@ defmodule :_next_ls_private_compiler do
   @moduledoc false
 
   def start do
+    Code.put_compiler_option(:parser_options, columns: true, token_metadata: true)
+
     children = [
       :_next_ls_private_compiler_worker
     ]
 
-    # See https://hexdocs.pm/elixir/Supervisor.html
-    # for other strategies and supported options
-    opts = [strategy: :one_for_one, name: :_next_ls_private_application_supervisor]
-    {:ok, pid} = Supervisor.start_link(children, opts)
+    {:ok, pid} = Supervisor.start_link(children, strategy: :one_for_one, name: :_next_ls_private_application_supervisor)
     Process.unlink(pid)
     {:ok, pid}
   end
@@ -1049,7 +1048,6 @@ defmodule :_next_ls_private_compiler do
   def compile do
     # keep stdout on this node
     Process.group_leader(self(), Process.whereis(:user))
-    Code.put_compiler_option(:parser_options, columns: true, token_metadata: true)
 
     Code.put_compiler_option(:tracers, [NextLSPrivate.DepTracer | @tracers])