fix: resolve CI test failures and improve Bun runtime reliability

- Fix FileWatcher initialization failure when inotify-tools are missing in CI
- Add proper error handling for Bun runtime startup failures
- Implement port retry logic for Bun integration tests to avoid EADDRINUSE conflicts
- Rename server.js.eex to server_bun.eex for better clarity
- Add BUN_PORT environment variable support to Bun server template
- Improve error handling in Bun runtime handle_continue callback

Fixes all CI test failures and ensures reliable runtime startup in various environments.

Author: GSMLG-BOT

lib/phoenix/mix/build/bun.ex

@@ -43,7 +43,7 @@ defmodule Mix.Tasks.Phx.React.Bun.Bundle do
         {basename, abs_path}
       end)
 
-    quoted = EEx.compile_file("#{__DIR__}/server.js.eex")
+    quoted = EEx.compile_file("#{__DIR__}/server_bun.eex")
     {result, _bindings} = Code.eval_quoted(quoted, files: files, base_dir: base_dir)
     tmp_file = "#{cd}/server.js"
     File.write!(tmp_file, result)

lib/phoenix/mix/build/server.js.eex lib/phoenix/mix/build/server_bun.eexlib/phoenix/mix/build/server.js.eex renamed to lib/phoenix/mix/build/server_bun.eex

@@ -8,11 +8,12 @@ import { Component as __component_<%= idx %> } from "<%= file %>";
 __comMap["<%= name %>"] = __component_<%= idx %>;
 <% end %>
 
-const { COMPONENT_BASE, BUN_ENV } = process.env;
+const { COMPONENT_BASE, BUN_ENV, BUN_PORT } = process.env;
 
 const isDev = BUN_ENV === 'development';
 
 const server = serve({
+  port: parseInt(BUN_PORT || "5225"),
   development: isDev,
   async fetch(req) {
     try {

lib/phoenix/react/runtime/bun.ex

@@ -40,21 +40,27 @@ defmodule Phoenix.React.Runtime.Bun do
   @impl true
   @spec handle_continue(:start_port, Phoenix.React.Runtime.t()) ::
           {:noreply, Phoenix.React.Runtime.t()}
+          | {:stop, reason :: term, Phoenix.React.Runtime.t()}
   def handle_continue(:start_port, %Runtime{component_base: component_base} = state) do
     if config()[:env] == :dev do
       start_file_watcher(component_base)
       Phoenix.React.Runtime.FileWatcher.set_ref(self())
     end
 
-    port = start(component_base: component_base)
+    case start(component_base: component_base) do
+      port when is_port(port) ->
+        Logger.debug(
+          "Bun.Server started on port: #{inspect(port)} and OS pid: #{get_port_os_pid(port)}"
+        )
 
-    Logger.debug(
-      "Bun.Server started on port: #{inspect(port)} and OS pid: #{get_port_os_pid(port)}"
-    )
+        Phoenix.React.Server.set_runtime_process(self())
 
-    Phoenix.React.Server.set_runtime_process(self())
+        {:noreply, %Runtime{state | runtime_port: port}}
 
-    {:noreply, %Runtime{state | runtime_port: port}}
+      {:error, reason} ->
+        Logger.error("Failed to start Bun server: #{inspect(reason)}")
+        {:stop, reason, state}
+    end
   end
 
   @impl true

test/phoenix/react/runtime_integration_test.exs

@@ -51,22 +51,41 @@ defmodule Phoenix.React.RuntimeIntegrationTest do
         flunk("Bun not available for integration testing")
       end
 
-      # Configure test environment with unique port
-      test_port = 15225 + :rand.uniform(1000)
-
-      Application.put_env(:phoenix_react_server, Bun,
-        cmd: System.find_executable("bun"),
-        port: test_port,
-        env: :dev,
-        cd: File.cwd!()
-      )
-
-      # Start the runtime without name registration
-      {:ok, pid} =
-        GenServer.start_link(Bun, component_base: "test/fixtures", render_timeout: 5000)
+      # Try multiple times to find an available port
+      {_test_port, pid} =
+        Enum.reduce_while(1..5, nil, fn _attempt, _acc ->
+          test_port = 15225 + :rand.uniform(1000)
+
+          Application.put_env(:phoenix_react_server, Bun,
+            cmd: System.find_executable("bun"),
+            port: test_port,
+            env: :dev,
+            cd: File.cwd!()
+          )
+
+          # Start the runtime without name registration
+          case GenServer.start_link(Bun, component_base: "test/fixtures", render_timeout: 5000) do
+            {:ok, pid} ->
+              # Give it time to start
+              Process.sleep(2000)
+
+              if Process.alive?(pid) do
+                {:halt, {test_port, pid}}
+              else
+                # Process died, try another port
+                {:cont, nil}
+              end
+
+            {:error, _reason} ->
+              # Failed to start, try another port
+              {:cont, nil}
+          end
+        end)
 
-      # Give it time to start
-      Process.sleep(2000)
+      # If we couldn't find a working port, fail the test
+      if pid == nil do
+        flunk("Could not start Bun runtime after 5 attempts")
+      end
 
       # Verify it's running
       assert Process.alive?(pid)