refactor(launcher): share Bun binary validation

Author: luvs01

bin/ocx.mjs

@@ -10,10 +10,11 @@
  */
 import { spawn, spawnSync } from "node:child_process";
 import { createRequire } from "node:module";
-import { existsSync, readFileSync, readdirSync, statSync } from "node:fs";
+import { existsSync, readFileSync, readdirSync } from "node:fs";
 import { homedir } from "node:os";
 import { dirname, join, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
+import { isRealBunBinary } from "../src/lib/bun-binary-validator.mjs";
 import { npmInvocation } from "../src/update/npm-invocation.mjs";
 import { handoffWindowsTrayForUpdate, planWindowsTrayUpdate } from "../src/update/tray-update-plan.mjs";
 
@@ -287,23 +288,8 @@ function bunBinDir() {
   return dirname(require.resolve("bun/package.json"));
 }
 
-// The `bun` package ships a tiny ASCII placeholder at bin/bun.exe until its
-// postinstall downloads the real ~60MB binary. --ignore-scripts / pnpm leave
-// the ~450-byte stub in place, which is NOT executable (ENOEXEC). A size gate
-// cleanly distinguishes the stub from a real binary on every platform. Keep
-// this Node-safe copy aligned with src/lib/bun-runtime.ts: the launcher cannot
-// import Bun-native TypeScript until after it has resolved a Bun executable.
-const REAL_BUN_MIN_BYTES = 1_000_000;
 const BUN_OVERRIDE_ENV = "OPENCODEX_BUN_PATH";
 
-function isRealBunBinary(path) {
-  try {
-    return existsSync(path) && statSync(path).size >= REAL_BUN_MIN_BYTES;
-  } catch {
-    return false;
-  }
-}
-
 function findBunBinary(bunDir) {
   // The npm `bun` package ships the binary as bin/bun.exe on every platform;
   // probe bin/bun too for forward compatibility.

src/lib/bun-binary-validator.d.mts

@@ -0,0 +1,3 @@
+export declare const REAL_BUN_MIN_BYTES: number;
+
+export declare function isRealBunBinary(path: string): boolean;

src/lib/bun-binary-validator.mjs

@@ -0,0 +1,18 @@
+import { existsSync, statSync } from "node:fs";
+
+// The `bun` package leaves a tiny ASCII placeholder at bin/bun.exe until its
+// postinstall downloads the real ~60MB binary. Keep the threshold and the
+// false-on-filesystem-error contract shared by the Node launcher and Bun code.
+export const REAL_BUN_MIN_BYTES = 1_000_000;
+
+/**
+ * @param {string} path
+ * @returns {boolean}
+ */
+export function isRealBunBinary(path) {
+  try {
+    return existsSync(path) && statSync(path).size >= REAL_BUN_MIN_BYTES;
+  } catch {
+    return false;
+  }
+}

src/lib/bun-runtime.ts

@@ -11,15 +11,13 @@
  * back to `process.execPath` (which is itself Bun when run via `bun src/cli/index.ts`).
  */
 import { createRequire } from "node:module";
-import { existsSync, statSync } from "node:fs";
 import { dirname, join } from "node:path";
+import { isRealBunBinary } from "./bun-binary-validator.mjs";
+
+export { isRealBunBinary };
 
 const require = createRequire(import.meta.url);
 
-// The `bun` package leaves a tiny ASCII placeholder at bin/bun.exe until its
-// postinstall downloads the real ~60MB binary; reject the stub by size so we
-// never bake a non-executable path into durable artifacts.
-const REAL_BUN_MIN_BYTES = 1_000_000;
 const BUN_OVERRIDE_ENV = "OPENCODEX_BUN_PATH";
 
 export type DurableBunRuntime = {
@@ -28,19 +26,6 @@ export type DurableBunRuntime = {
   overrideEnv: typeof BUN_OVERRIDE_ENV;
 };
 
-/**
- * True only for a real, downloaded Bun binary — not the ~450-byte ASCII
- * placeholder stub left by `--ignore-scripts` / pnpm. A size gate cleanly
- * separates the two on every platform (real binary is tens of MB).
- */
-export function isRealBunBinary(path: string): boolean {
-  try {
-    return existsSync(path) && statSync(path).size >= REAL_BUN_MIN_BYTES;
-  } catch {
-    return false;
-  }
-}
-
 /**
  * Absolute path to the bundled Bun binary, or null if the `bun` dependency is
  * not installed/resolvable (or only the un-downloaded placeholder is present).

tests/ocx-launcher-runtime.test.ts

@@ -177,9 +177,6 @@ function removeTree(path: string): void {
 
 async function effectiveRuntime(override: string): Promise<string> {
   const root = mkdtempSync(join(tmpdir(), "ocx-launcher-runtime-"));
-  const opencodexHome = join(root, "opencodex");
-  const codexHome = join(root, "codex");
-  const grokHome = join(root, "grok");
   let port: number | null = null;
   let launcher: ChildProcess | null = null;
   let launcherPid: number | null = null;
@@ -189,22 +186,11 @@ async function effectiveRuntime(override: string): Promise<string> {
   let hasPrimaryError = false;
   let primaryError: unknown;
   try {
-    mkdirSync(opencodexHome, { recursive: true });
-    mkdirSync(codexHome, { recursive: true });
-    mkdirSync(grokHome, { recursive: true });
     port = await freePort();
     launcher = spawn("node", [BIN_OCX, "start", "--port", String(port)], {
       stdio: "ignore",
       windowsHide: true,
-      env: {
-        ...process.env,
-        HOME: root,
-        USERPROFILE: root,
-        OPENCODEX_HOME: opencodexHome,
-        CODEX_HOME: codexHome,
-        GROK_HOME: grokHome,
-        OPENCODEX_BUN_PATH: override,
-      },
+      env: isolatedLauncherEnv(root, override),
     });
     if (!launcher.pid) throw new Error("Node launcher has no process id");
     launcherPid = launcher.pid;

tests/ocx-launcher-source.test.ts

@@ -7,6 +7,11 @@ import { join } from "node:path";
  * cannot be imported by tests. Guard its Windows-critical invariants at the source level.
  */
 const source = readFileSync(join(import.meta.dir, "..", "bin", "ocx.mjs"), "utf8");
+const runtimeSource = readFileSync(join(import.meta.dir, "..", "src", "lib", "bun-runtime.ts"), "utf8");
+const validatorSource = readFileSync(
+  join(import.meta.dir, "..", "src", "lib", "bun-binary-validator.mjs"),
+  "utf8",
+);
 
 describe("ocx.mjs npm launcher (source invariants)", () => {
   test("Windows npm spawns use the trusted absolute invocation without shell lookup", () => {
@@ -51,14 +56,16 @@ describe("ocx.mjs npm launcher (source invariants)", () => {
   });
 
   test("invalid Bun overrides warn safely and fall back without throwing", () => {
-    expect(source).toContain("function isRealBunBinary(path) {");
-    expect(source).toMatch(/function isRealBunBinary\(path\) \{[\s\S]*?try \{[\s\S]*?statSync\(path\)[\s\S]*?catch \{[\s\S]*?return false;/);
+    expect(source).toContain('import { isRealBunBinary } from "../src/lib/bun-binary-validator.mjs";');
     expect(source).toContain("is missing, unreadable, or not a complete Bun binary; falling back to the bundled runtime.");
     expect(source).not.toContain('${override} is missing, unreadable');
   });
 
-  test("documents why the Node launcher keeps a synchronized validator copy", () => {
-    expect(source).toContain("this Node-safe copy aligned with src/lib/bun-runtime.ts");
-    expect(source).toContain("cannot\n// import Bun-native TypeScript until after it has resolved a Bun executable");
+  test("shares the Node-safe Bun binary validator across both runtime paths", () => {
+    expect(source).toContain('import { isRealBunBinary } from "../src/lib/bun-binary-validator.mjs";');
+    expect(runtimeSource).toContain('import { isRealBunBinary } from "./bun-binary-validator.mjs";');
+    expect(runtimeSource).toContain("export { isRealBunBinary };");
+    expect(validatorSource).toContain("export const REAL_BUN_MIN_BYTES = 1_000_000;");
+    expect(validatorSource).toMatch(/export function isRealBunBinary\(path\) \{[\s\S]*?try \{[\s\S]*?statSync\(path\)[\s\S]*?catch \{[\s\S]*?return false;/);
   });
 });