test: add fs.writeSync optional params test and fix

src/js/node/fs.ts

@@ -562,7 +562,23 @@ var access = function access(path, mode, callback) {
 
     return fs.readSync(fd, buffer, offset, length, position);
   },
-  writeSync = fs.writeSync.bind(fs),
+  writeSync = function writeSync(fd, buffer, offsetOrOptions, length, position) {
+    if ($isTypedArrayView(buffer)) {
+      let offset = offsetOrOptions;
+      if (arguments.length <= 3 || typeof offsetOrOptions === "object") {
+        if (offsetOrOptions !== undefined) {
+          if (typeof offsetOrOptions !== "object" || $isArray(offsetOrOptions)) {
+            throw $ERR_INVALID_ARG_TYPE("options", "object", offsetOrOptions);
+          }
+        }
+        ({ offset = 0, length = buffer.byteLength - offset, position = null } = offsetOrOptions ?? {});
+      }
+
+      return fs.writeSync(fd, buffer, offset, length, position);
+    }
+
+    return fs.writeSync(fd, buffer, offsetOrOptions, length);
+  },
   readdirSync = fs.readdirSync.bind(fs),
   readFileSync = fs.readFileSync.bind(fs),
   fdatasyncSync = fs.fdatasyncSync.bind(fs),

test/js/node/test/parallel/test-fs-write-sync-optional-params.js

@@ -0,0 +1,102 @@
+const common = require('../common');
+
+// This test ensures that fs.writeSync accepts "named parameters" object
+// and doesn't interpret objects as strings
+
+const assert = require('assert');
+const fs = require('fs');
+const tmpdir = require('../common/tmpdir');
+
+tmpdir.refresh();
+
+const dest = tmpdir.resolve('tmp.txt');
+const buffer = Buffer.from('zyx');
+
+function testInvalid(dest, expectedCode, ...bufferAndOptions) {
+  if (bufferAndOptions.length >= 2) {
+    bufferAndOptions[1] = common.mustNotMutateObjectDeep(bufferAndOptions[1]);
+  }
+  let fd;
+  try {
+    fd = fs.openSync(dest, 'w+');
+    assert.throws(
+      () => fs.writeSync(fd, ...bufferAndOptions),
+      { code: expectedCode });
+  } finally {
+    if (fd != null) fs.closeSync(fd);
+  }
+}
+
+function testValid(dest, buffer, options) {
+  const length = options?.length;
+  let fd, bytesWritten, bytesRead;
+
+  try {
+    fd = fs.openSync(dest, 'w');
+    bytesWritten = fs.writeSync(fd, buffer, options);
+  } finally {
+    if (fd != null) fs.closeSync(fd);
+  }
+
+  try {
+    fd = fs.openSync(dest, 'r');
+    bytesRead = fs.readSync(fd, buffer, options);
+  } finally {
+    if (fd != null) fs.closeSync(fd);
+  }
+
+  assert.ok(bytesWritten >= bytesRead);
+  if (length !== undefined && length !== null) {
+    assert.strictEqual(bytesWritten, length);
+    assert.strictEqual(bytesRead, length);
+  }
+}
+
+{
+  // Test if second argument is not wrongly interpreted as string or options
+  for (const badBuffer of [
+    undefined, null, true, 42, 42n, Symbol('42'), NaN, [], () => {},
+    common.mustNotCall(),
+    common.mustNotMutateObjectDeep({}),
+    {},
+    { buffer: 'amNotParam' },
+    { string: 'amNotParam' },
+    { buffer: new Uint8Array(1) },
+    { buffer: new Uint8Array(1).buffer },
+    Promise.resolve(new Uint8Array(1)),
+    new Date(),
+    new String('notPrimitive'),
+    { toString() { return 'amObject'; } },
+    { [Symbol.toPrimitive]: (hint) => 'amObject' },
+  ]) {
+    testInvalid(dest, 'ERR_INVALID_ARG_TYPE', common.mustNotMutateObjectDeep(badBuffer));
+  }
+
+  // First argument (buffer or string) is mandatory
+  testInvalid(dest, 'ERR_INVALID_ARG_TYPE');
+
+  // Various invalid options
+  testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { length: 5 });
+  testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { offset: 5 });
+  testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { length: 1, offset: 3 });
+  testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { length: -1 });
+  testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { offset: -1 });
+  testInvalid(dest, 'ERR_INVALID_ARG_TYPE', buffer, { offset: false });
+  testInvalid(dest, 'ERR_INVALID_ARG_TYPE', buffer, { offset: true });
+
+  // Test compatibility with fs.readSync counterpart with reused options
+  for (const options of [
+    undefined,
+    null,
+    {},
+    { length: 1 },
+    { position: 5 },
+    { length: 1, position: 5 },
+    { length: 1, position: -1, offset: 2 },
+    { length: null },
+    { position: null },
+    { offset: 1 },
+  ]) {
+    testValid(dest, buffer, common.mustNotMutateObjectDeep(options));
+  }
+}