feat(FN-5611): strip react devtools from bun compile builds

Complete the standalone build pipeline fix by setting `DEV=false` during bun compile to eliminate React DevTools from production executables, with hardened regression tests and documentation.

Fusion-Task-Id: FN-5611

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>
Fusion-Task-Id: FN-5611

.changeset/fn-5611-bun-compile-react-devtools.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix the Bun-compiled `fn` executable so `--help` no longer crashes with a missing `react-devtools-core` module. The build now defines `process.env.DEV` as `false` during compile, allowing Ink's DEV-only devtools import path to be removed from the bundled binary.

packages/cli/STANDALONE.md

@@ -160,6 +160,8 @@ Prebuilt standalone binaries are available that require no Node.js runtime. You
 bun run build.ts
 ```
 
+The standalone build defines `process.env.DEV` as `false` at compile time so Ink's DEV-only React devtools import path is removed from the binary (preventing runtime `react-devtools-core` resolution failures).
+
 ### Runtime Assets
 
 When using standalone binaries, the dashboard's integrated terminal requires native platform assets that must be co-located with the binary:

packages/cli/build.ts

@@ -16,6 +16,9 @@
  * Notes:
  *   - If dashboard client assets are missing, this script generates a
  *     minimal dist/client/index.html stub so clean-checkout tests can run.
+ *   - Ink's DEV-only react-devtools import is eliminated at compile time via
+ *     --define "process.env.DEV='false'" to keep the standalone binary
+ *     self-contained without node_modules.
  */
 
 import { join, dirname } from "node:path";
@@ -339,10 +342,11 @@ function compileBinary(outFile: string, target: string, isCrossCompile: boolean)
       target,
       "--minify",
       "--conditions=source",
-      // ink imports react-devtools-core dynamically only when DEV=true; mark
-      // external so Bun's static bundler doesn't try to resolve it at compile.
-      "--external",
-      "react-devtools-core",
+      // Ink conditionally loads devtools when process.env.DEV === "true".
+      // Force DEV to false at compile-time so Bun/minify can eliminate that branch
+      // and avoid shipping runtime references to react-devtools-core.
+      "--define",
+      "process.env.DEV='false'",
       // cpu-features: native .node binding from ssh2 (transitive via dockerode); ssh2 falls back to pure JS when unavailable
       "--external",
       "cpu-features",

packages/cli/src/__tests__/build-exe-cross.test.ts

@@ -90,7 +90,14 @@ describe.skipIf(!SHOULD_RUN_BUILD_EXE)("build-exe-cross: --all builds all platfo
     const allBuilt = SUPPORTED_TARGETS.every((target) =>
       existsSync(join(distDir, expectedBinaryName(target))),
     );
-    if (allBuilt) return;
+    const platform = process.platform === "darwin" ? "darwin" :
+      process.platform === "linux" ? "linux" :
+      process.platform === "win32" ? "win32" : "unknown";
+    const arch = process.arch === "arm64" ? "arm64" :
+      process.arch === "x64" ? "x64" : "unknown";
+    const hostRuntimeDir = join(distDir, "runtime", `${platform}-${arch}`);
+    const hostRuntimeReady = existsSync(join(hostRuntimeDir, "pty.node"));
+    if (allBuilt && hostRuntimeReady) return;
     execSync("bun run build.ts --all", {
       cwd: cliRoot,
       stdio: "pipe",
@@ -121,6 +128,16 @@ describe.skipIf(!SHOULD_RUN_BUILD_EXE)("build-exe-cross: --all builds all platfo
     const prebuildName = `${platform}-${arch}`;
     const runtimeDir = join(distDir, "runtime", prebuildName);
     
+    if (!existsSync(join(runtimeDir, "pty.node"))) {
+      // Ensure host-native runtime assets exist even if a previous --all build
+      // ended on a non-host target.
+      execSync("bun run build.ts", {
+        cwd: cliRoot,
+        stdio: "pipe",
+        timeout: 120_000,
+      });
+    }
+
     // pty.node is required for all platforms
     expect(existsSync(join(runtimeDir, "pty.node"))).toBe(true);
     // spawn-helper is only for Unix platforms

packages/cli/src/__tests__/build-exe.test.ts

@@ -10,6 +10,7 @@ const outBinary = join(cliRoot, "dist", process.platform === "win32" ? "fn.exe"
 const binaryName = process.platform === "win32" ? "fn.exe" : "fn";
 const clientDir = join(cliRoot, "dist", "client");
 const runtimeDir = join(cliRoot, "dist", "runtime");
+const childEnv = { ...process.env, VITEST: "false" };
 
 /**
  * Create an isolated temp directory containing the binary, client/,
@@ -72,6 +73,7 @@ type AsyncSpawnResult = {
 async function runCommandWithTimeout(binary: string, args: string[], timeoutMs: number): Promise<AsyncSpawnResult> {
   const child = spawn(binary, args, {
     stdio: ["ignore", "pipe", "pipe"],
+    env: childEnv,
   });
 
   let stdout = "";
@@ -179,6 +181,7 @@ describe("build-exe", () => {
         expect(result.stdout).toContain("dashboard");
         expect(result.stdout).toContain("task create");
         expect(result.stdout).toContain("task list");
+        expect(result.stderr).not.toContain("react-devtools-core");
       } finally {
         cleanup();
       }
@@ -192,12 +195,14 @@ describe("build-exe", () => {
       const result = spawnSync(binary, ["task", "list"], {
         encoding: "utf-8",
         timeout: 30_000,
+        env: childEnv,
       });
       if (hasKnownBunSqliteLimitation(result)) {
         return;
       }
       expect(result.status).toBe(0);
       expect(result.stdout).toContain("No tasks yet");
+      expect(result.stderr ?? "").not.toContain("react-devtools-core");
     } finally {
       cleanup();
     }
@@ -212,9 +217,10 @@ describe("build-exe", () => {
     try {
       // Ask the OS for an ephemeral port so this smoke test never collides
       // with a developer's running dashboard or dev server.
-      child = spawn(binary, ["dashboard", "-p", "0"], {
+      child = spawn(binary, ["dashboard", "-p", "0", "--no-auth"], {
         cwd: dir,
         stdio: ["ignore", "pipe", "pipe"],
+        env: childEnv,
       });
 
       if (!child.stdout || !child.stderr) {