Handle Node.js Debug Messages and Improve Port Termination

CHANGELOG.md

@@ -5,6 +5,21 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [3.1.3]
+
+### Added
+- Added `debug_mode` configuration option to handle Node.js stdout/stderr messages
+- Implemented proper `handle_info/2` callback to handle messages from Node.js processes
+- Added safeguards to reset_terminal to prevent errors during termination with invalid ports
+
+### Fixed
+- Fixed "unexpected message in handle_info/2" errors when Node.js emits debug messages
+- Fixed potential crashes during termination when a port becomes invalid
+
+### Contributors
+- @francois-codes for the initial implementation
+- Revelry team for refinements
+
 ## [3.1.2]
 
 ### Changed

README.md

@@ -36,6 +36,22 @@ directory containing your JavaScript modules.
 supervisor(NodeJS, [[path: "/node_app_root", pool_size: 4]])
 ```
 
+### Debug Mode
+
+When working with Node.js applications, you may encounter debug messages or warnings from the Node.js runtime, especially when using inspector or debugging tools. To properly handle these messages:
+
+```elixir
+# In your config/dev.exs or other appropriate config file
+config :nodejs, debug_mode: true
+```
+
+When `debug_mode` is enabled:
+- Node.js stdout/stderr messages will be logged at the info level
+- Messages like "Debugger listening on..." will not cause errors
+- All Node.js processes will log their output through Elixir's Logger
+
+This is particularly useful during development or when debugging Node.js integration issues.
+
 ### Calling JavaScript module functions with `NodeJS.call(module, args \\ [])`.
 
 If the module exports a function directly, like this:
@@ -111,4 +127,4 @@ module.exports = async function echo(x, delay = 1000) {
 }
 ```
 
-https://github.com/revelrylabs/elixir-nodejs/blob/master/test/js/slow-async-echo.js
+https://github.com/revelrylabs/elixir-nodejs/blob/master/test/js/slow-async-echo.js

lib/nodejs/worker.ex

@@ -124,21 +124,28 @@ defmodule NodeJS.Worker do
     end
   end
 
-  defp env do
-    Mix.env()
-  rescue
-    _ -> :release
+  # Determines if debug mode is enabled via application configuration
+  defp debug_mode? do
+    Application.get_env(:nodejs, :debug_mode, false)
   end
 
-  def handle_info({_pid, data}, state) do
-    with :dev <- env(),
-         {_, {:eol, msg}} <- data do
+  # Handles any messages from the Node.js process
+  # When debug_mode is enabled, these messages (like Node.js debug info)
+  # will be logged at info level
+  @doc false
+  def handle_info({_pid, {:data, {_flag, msg}}}, state) do
+    if debug_mode?() do
       Logger.info("NodeJS: #{msg}")
     end
 
     {:noreply, state}
   end
 
+  # Catch-all handler for other messages
+  def handle_info(_message, state) do
+    {:noreply, state}
+  end
+
   defp decode(data) do
     data
     |> to_string()
@@ -149,9 +156,16 @@ defmodule NodeJS.Worker do
     end
   end
 
+  # Safely resets the terminal, handling potential errors if
+  # the port is already closed or invalid
   defp reset_terminal(port) do
-    Port.command(port, "\x1b[0m\x1b[?7h\x1b[?25h\x1b[H\x1b[2J")
-    Port.command(port, "\x1b[!p\x1b[?47l")
+    try do
+      Port.command(port, "\x1b[0m\x1b[?7h\x1b[?25h\x1b[H\x1b[2J")
+      Port.command(port, "\x1b[!p\x1b[?47l")
+    rescue
+      _ ->
+        Logger.debug("NodeJS: Could not reset terminal - port may be closed")
+    end
   end
 
   @doc false

mix.exs

@@ -4,7 +4,7 @@ defmodule NodeJS.MixProject do
   def project do
     [
       app: :nodejs,
-      version: "3.1.2",
+      version: "3.1.3",
       elixir: "~> 1.12",
       start_permanent: Mix.env() == :prod,
       deps: deps(),

test/nodejs_test.exs

@@ -277,4 +277,45 @@ defmodule NodeJS.Test do
       assert Enum.all?(results, &match?({:ok, "clean output"}, &1))
     end
   end
+
+  describe "debug mode" do
+    test "handles debug messages without crashing" do
+      File.mkdir_p!("test/js/debug_test")
+
+      File.write!("test/js/debug_test/debug_logger.js", """
+      // This file outputs debugging information to stdout
+      console.log("Debug message: Module loading");
+      console.debug("Debug message: Initializing module");
+
+      module.exports = function testFunction(input) {
+        console.log(`Debug message: Function called with input: ${input}`);
+        console.debug("Debug message: Processing input");
+
+        return `Processed: ${input}`;
+      };
+      """)
+
+      # With debug_mode disabled, function still works despite debug output
+      result = NodeJS.call("debug_test/debug_logger", ["test input"])
+      assert {:ok, "Processed: test input"} = result
+
+      # Enable debug_mode to verify it works in that mode too
+      original_setting = Application.get_env(:nodejs, :debug_mode)
+      Application.put_env(:nodejs, :debug_mode, true)
+
+      # Function still works with debug_mode enabled
+      result = NodeJS.call("debug_test/debug_logger", ["test input"])
+      assert {:ok, "Processed: test input"} = result
+
+      # Restore original setting
+      if is_nil(original_setting) do
+        Application.delete_env(:nodejs, :debug_mode)
+      else
+        Application.put_env(:nodejs, :debug_mode, original_setting)
+      end
+
+      # Clean up
+      File.rm!("test/js/debug_test/debug_logger.js")
+    end
+  end
 end