fs: make params in writing methods optional

This change allows passing objects as "named parameters":
- `fs.write(fd, buffer[, options], callback)`
- `fs.writeSync(fd, buffer[, options])`
- `filehandle.write(buffer[, options])`

Fixes: https://github.com/nodejs/node/issues/41666

PR-URL: https://github.com/nodejs/node/pull/42601
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

3 files changed, 286 insertions, 0 deletions

diff --git a/test/parallel/test-fs-promises-write-optional-params.js b/test/parallel/test-fs-promises-write-optional-params.js
new file mode 100644
index 00000000000..b130c491541
--- /dev/null
+++ b/test/parallel/test-fs-promises-write-optional-params.js
@@ -0,0 +1,95 @@
+'use strict';
+
+const common = require('../common');
+
+// This test ensures that filehandle.write accepts "named parameters" object
+// and doesn't interpret objects as strings
+
+const assert = require('assert');
+const fsPromises = require('fs').promises;
+const path = require('path');
+const tmpdir = require('../common/tmpdir');
+
+tmpdir.refresh();
+
+const dest = path.resolve(tmpdir.path, 'tmp.txt');
+const buffer = Buffer.from('zyx');
+
+async function testInvalid(dest, expectedCode, ...params) {
+  let fh;
+  try {
+    fh = await fsPromises.open(dest, 'w+');
+    await assert.rejects(
+      fh.write(...params),
+      { code: expectedCode });
+  } finally {
+    await fh?.close();
+  }
+}
+
+async function testValid(dest, buffer, options) {
+  let fh;
+  try {
+    fh = await fsPromises.open(dest, 'w+');
+    const writeResult = await fh.write(buffer, options);
+    const writeBufCopy = Uint8Array.prototype.slice.call(writeResult.buffer);
+
+    const readResult = await fh.read(buffer, options);
+    const readBufCopy = Uint8Array.prototype.slice.call(readResult.buffer);
+
+    assert.ok(writeResult.bytesWritten >= readResult.bytesRead);
+    if (options.length !== undefined && options.length !== null) {
+      assert.strictEqual(writeResult.bytesWritten, options.length);
+    }
+    if (options.offset === undefined || options.offset === 0) {
+      assert.deepStrictEqual(writeBufCopy, readBufCopy);
+    }
+    assert.deepStrictEqual(writeResult.buffer, readResult.buffer);
+  } finally {
+    await fh?.close();
+  }
+}
+
+(async () => {
+  // Test if first argument is not wrongly interpreted as ArrayBufferView|string
+  for (const badBuffer of [
+    undefined, null, true, 42, 42n, Symbol('42'), NaN, [], () => {},
+    Promise.resolve(new Uint8Array(1)),
+    {},
+    { buffer: 'amNotParam' },
+    { string: 'amNotParam' },
+    { buffer: new Uint8Array(1).buffer },
+    new Date(),
+    new String('notPrimitive'),
+    { toString() { return 'amObject'; } },
+    { [Symbol.toPrimitive]: (hint) => 'amObject' },
+  ]) {
+    await testInvalid(dest, 'ERR_INVALID_ARG_TYPE', badBuffer, {});
+  }
+
+  // First argument (buffer or string) is mandatory
+  await testInvalid(dest, 'ERR_INVALID_ARG_TYPE');
+
+  // Various invalid options
+  await testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { length: 5 });
+  await testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { offset: 5 });
+  await testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { length: 1, offset: 3 });
+  await testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { length: -1 });
+  await testInvalid(dest, 'ERR_OUT_OF_RANGE', buffer, { offset: -1 });
+  await testInvalid(dest, 'ERR_INVALID_ARG_TYPE', buffer, { offset: false });
+  await testInvalid(dest, 'ERR_INVALID_ARG_TYPE', buffer, { offset: true });
+
+  // Test compatibility with filehandle.read counterpart
+  for (const options of [
+    {},
+    { length: 1 },
+    { position: 5 },
+    { length: 1, position: 5 },
+    { length: 1, position: -1, offset: 2 },
+    { length: null },
+    { position: null },
+    { offset: 1 },
+  ]) {
+    await testValid(dest, buffer, options);
+  }
+})().then(common.mustCall());
diff --git a/test/parallel/test-fs-write-optional-params.js b/test/parallel/test-fs-write-optional-params.js
new file mode 100644
index 00000000000..21732114153
--- /dev/null
+++ b/test/parallel/test-fs-write-optional-params.js
@@ -0,0 +1,102 @@
+'use strict';
+
+const common = require('../common');
+
+// This test ensures that fs.write accepts "named parameters" object
+// and doesn't interpret objects as strings
+
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+const tmpdir = require('../common/tmpdir');
+const util = require('util');
+
+tmpdir.refresh();
+
+const destInvalid = path.resolve(tmpdir.path, 'rwopt_invalid');
+const buffer = Buffer.from('zyx');
+
+function testInvalidCb(fd, expectedCode, buffer, options, callback) {
+  assert.throws(
+    () => fs.write(fd, buffer, options, common.mustNotCall()),
+    { code: expectedCode }
+  );
+  callback(0);
+}
+
+function testValidCb(buffer, options, index, callback) {
+  const dest = path.resolve(tmpdir.path, `rwopt_valid_${index}`);
+  fs.open(dest, 'w+', common.mustSucceed((fd) => {
+    fs.write(fd, buffer, options, common.mustSucceed((bytesWritten, bufferWritten) => {
+      const writeBufCopy = Uint8Array.prototype.slice.call(bufferWritten);
+
+      fs.read(fd, buffer, options, common.mustSucceed((bytesRead, bufferRead) => {
+        const readBufCopy = Uint8Array.prototype.slice.call(bufferRead);
+
+        assert.ok(bytesWritten >= bytesRead);
+        if (options.length !== undefined && options.length !== null) {
+          assert.strictEqual(bytesWritten, options.length);
+        }
+        if (options.offset === undefined || options.offset === 0) {
+          assert.deepStrictEqual(writeBufCopy, readBufCopy);
+        }
+        assert.deepStrictEqual(bufferWritten, bufferRead);
+        fs.close(fd, common.mustSucceed(callback));
+      }));
+    }));
+  }));
+}
+
+// Promisify to reduce flakiness
+const testInvalid = util.promisify(testInvalidCb);
+const testValid = util.promisify(testValidCb);
+
+async function runTests(fd) {
+  // Test if first argument is not wrongly interpreted as ArrayBufferView|string
+  for (const badBuffer of [
+    undefined, null, true, 42, 42n, Symbol('42'), NaN, [], () => {},
+    Promise.resolve(new Uint8Array(1)),
+    {},
+    { buffer: 'amNotParam' },
+    { string: 'amNotParam' },
+    { buffer: new Uint8Array(1).buffer },
+    new Date(),
+    new String('notPrimitive'),
+    { [Symbol.toPrimitive]: (hint) => 'amObject' },
+
+    // TODO(LiviaMedeiros): add the following after DEP0162 EOL
+    // { toString() { return 'amObject'; } },
+  ]) {
+    await testInvalid(fd, 'ERR_INVALID_ARG_TYPE', badBuffer, {});
+  }
+
+  // First argument (buffer or string) is mandatory
+  await testInvalid(fd, 'ERR_INVALID_ARG_TYPE', undefined, undefined);
+
+  // Various invalid options
+  await testInvalid(fd, 'ERR_OUT_OF_RANGE', buffer, { length: 5 });
+  await testInvalid(fd, 'ERR_OUT_OF_RANGE', buffer, { offset: 5 });
+  await testInvalid(fd, 'ERR_OUT_OF_RANGE', buffer, { length: 1, offset: 3 });
+  await testInvalid(fd, 'ERR_OUT_OF_RANGE', buffer, { length: -1 });
+  await testInvalid(fd, 'ERR_OUT_OF_RANGE', buffer, { offset: -1 });
+  await testInvalid(fd, 'ERR_INVALID_ARG_TYPE', buffer, { offset: false });
+  await testInvalid(fd, 'ERR_INVALID_ARG_TYPE', buffer, { offset: true });
+
+  // Test compatibility with fs.read counterpart
+  for (const [ index, options ] of [
+    {},
+    { length: 1 },
+    { position: 5 },
+    { length: 1, position: 5 },
+    { length: 1, position: -1, offset: 2 },
+    { length: null },
+    { position: null },
+    { offset: 1 },
+  ].entries()) {
+    await testValid(buffer, options, index);
+  }
+}
+
+fs.open(destInvalid, 'w+', common.mustSucceed(async (fd) => {
+  runTests(fd).then(common.mustCall(() => fs.close(fd, common.mustSucceed())));
+}));
diff --git a/test/parallel/test-fs-write-sync-optional-params.js b/test/parallel/test-fs-write-sync-optional-params.js
new file mode 100644
index 00000000000..80dfa51e0ba
--- /dev/null
+++ b/test/parallel/test-fs-write-sync-optional-params.js
@@ -0,0 +1,89 @@
+'use strict';
+
+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 path = require('path');
+const tmpdir = require('../common/tmpdir');
+
+tmpdir.refresh();
+
+const dest = path.resolve(tmpdir.path, 'tmp.txt');
+const buffer = Buffer.from('zyx');
+
+function testInvalid(dest, expectedCode, ...bufferAndOptions) {
+  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) {
+  let fd;
+  try {
+    fd = fs.openSync(dest, 'w+');
+    const bytesWritten = fs.writeSync(fd, buffer, options);
+    const bytesRead = fs.readSync(fd, buffer, options);
+
+    assert.ok(bytesWritten >= bytesRead);
+    if (options.length !== undefined && options.length !== null) {
+      assert.strictEqual(bytesWritten, options.length);
+    }
+  } finally {
+    if (fd != null) fs.closeSync(fd);
+  }
+}
+
+{
+  // Test if second argument is not wrongly interpreted as string or options
+  for (const badBuffer of [
+    undefined, null, true, 42, 42n, Symbol('42'), NaN, [], () => {},
+    {},
+    { 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', 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 [
+    {},
+    { length: 1 },
+    { position: 5 },
+    { length: 1, position: 5 },
+    { length: 1, position: -1, offset: 2 },
+    { length: null },
+    { position: null },
+    { offset: 1 },
+  ]) {
+    testValid(dest, buffer, options);
+  }
+}