revert to old writeFast for ci

src/js/internal/fs/streams.ts

@@ -634,23 +634,60 @@ function underscoreWriteFast(this: FSStream, data: any, encoding: any, cb: any)
 const writablePrototypeWrite = Writable.prototype.write;
 const kWriteMonkeyPatchDefense = Symbol("!");
 function writeFast(this: FSStream, data: any, encoding: any, cb: any) {
-  if (this[kWriteMonkeyPatchDefense]) return writablePrototypeWrite.$call(this, data, encoding, cb);
-
-  if (typeof encoding === "function") {
+  if (encoding != null && typeof encoding === "function") {
     cb = encoding;
-    encoding = undefined;
+    encoding = null;
   }
-  if (typeof cb !== "function") {
-    cb = streamNoop;
+  let fileSink = this[kWriteStreamFastPath];
+  if (!fileSink) {
+    this.write = Writable.prototype.write;
+    return this.write(data, encoding, cb);
+  } else if (fileSink === true) {
+    if (
+      this.open !== streamNoop ||
+      fs.open !== open ||
+      fs.write !== write ||
+      fs.fsync !== fsync ||
+      fs.close !== close
+    ) {
+      this[kWriteStreamFastPath] = undefined;
+      this.write = Writable.prototype.write;
+      return this.write(data, encoding, cb);
+    }
+    fileSink = this[kWriteStreamFastPath] = Bun.file(this.path).writer();
   }
-  const result: any = this._write(data, encoding, cb);
-  if (this.write === writeFast) {
-    this.write = writablePrototypeWrite;
-  } else {
-    // test-console-group.js
-    this[kWriteMonkeyPatchDefense] = true;
+  try {
+    $assert(fs.write === write, "this patching case not handled, and likely does not matter");
+    const maybePromise = fileSink.write(data);
+    if (
+      $isPromise(maybePromise) &&
+      ($getPromiseInternalField(maybePromise, $promiseFieldFlags) & $promiseStateMask) === $promiseStatePending
+    ) {
+      const prevRefCount = this[kIsPerformingIO];
+      this[kIsPerformingIO] = (prevRefCount === true ? 0 : prevRefCount || 0) + 1;
+      if (typeof cb === "function")
+        maybePromise.then(() => {
+          cb(null);
+          if (
+            (this[kIsPerformingIO] -= 1) === 0 &&
+            ((this[kWriteFastSimpleBuffering] = false), this[kWriteStreamFastPathClosed])
+          ) {
+            this.emit(kIoDone, null);
+          }
+        }, cb);
+      return false;
+    } else {
+      if (typeof cb === "function") process.nextTick(cb, null);
+    }
+    return true;
+  } catch (e) {
+    if (typeof cb === "function") process.nextTick(cb, e);
+    else
+      process.nextTick(() => {
+        this.emit("error", e);
+      });
+    return false;
   }
-  return result;
 }
 
 writeStreamPrototype._writev = function (data, cb) {

test/regression/issue/16702/16702.test.ts

@@ -0,0 +1,33 @@
+import { bunExe } from "harness";
+
+test("order", async () => {
+  const res = Bun.spawnSync({
+    cmd: [bunExe(), import.meta.dir + "/order-fixture.js"],
+    stdio: ["pipe", "pipe", "pipe"],
+  });
+  expect({
+    stdout: res.stdout.toString(),
+    stderr: res.stderr.toString(),
+    exitCode: res.exitCode,
+  }).toEqual({
+    stdout: "l1\nl2\nl3\n",
+    stderr: "",
+    exitCode: 0,
+  });
+});
+
+test("exit", async () => {
+  const res = Bun.spawnSync({
+    cmd: [bunExe(), import.meta.dir + "/exit-fixture.js"],
+    stdio: ["pipe", "pipe", "pipe"],
+  });
+  expect({
+    stdout: res.stdout.toString(),
+    stderr: res.stderr.toString(),
+    exitCode: res.exitCode,
+  }).toEqual({
+    stdout: "l1\nl2\n",
+    stderr: "",
+    exitCode: 0,
+  });
+});

test/regression/issue/16702/exit-fixture.js

@@ -0,0 +1,29 @@
+process.stdout.write("l1\n");
+process.stdout.write("l2\n");
+process.exit(0);
+
+// <l1>
+// old_1
+// old_5
+// old_6
+// old_15
+// old_16
+// old_17
+//   l1
+// old_18
+// old_29
+// old_30
+// old_31
+// </l1><l2>
+// old_1
+// old_5
+// old_6
+// old_15
+// old_16
+// old_17
+//   l2
+// old_18
+// old_29
+// old_30
+// old_31
+// </l2>

test/regression/issue/16702/order-fixture.js

@@ -0,0 +1,3 @@
+process.stdout.write("l1\n");
+process.stdout.write("l2\n");
+console.log("l3");