feat(ext/node): buffer.transcode() (#25972)

Closes https://github.com/denoland/deno/issues/25911

3 files changed, 98 insertions, 1 deletions

diff --git a/tests/node_compat/config.jsonc b/tests/node_compat/config.jsonc
index 2f94fa2f2..bc9bf476b 100644
--- a/tests/node_compat/config.jsonc
+++ b/tests/node_compat/config.jsonc
@@ -406,6 +406,7 @@
       "test-http-outgoing-settimeout.js",
       "test-http-url.parse-https.request.js",
       "test-http-url.parse-only-support-http-https-protocol.js",
+      "test-icu-transcode.js",
       "test-net-access-byteswritten.js",
       "test-net-better-error-messages-listen-path.js",
       "test-net-better-error-messages-path.js",
diff --git a/tests/node_compat/runner/TODO.md b/tests/node_compat/runner/TODO.md
index 24e827182..99258f5a5 100644
--- a/tests/node_compat/runner/TODO.md
+++ b/tests/node_compat/runner/TODO.md
@@ -1632,7 +1632,6 @@ NOTE: This file should not be manually edited. Please edit `tests/node_compat/co
 - [parallel/test-icu-minimum-version.js](https://github.com/nodejs/node/tree/v18.12.1/test/parallel/test-icu-minimum-version.js)
 - [parallel/test-icu-punycode.js](https://github.com/nodejs/node/tree/v18.12.1/test/parallel/test-icu-punycode.js)
 - [parallel/test-icu-stringwidth.js](https://github.com/nodejs/node/tree/v18.12.1/test/parallel/test-icu-stringwidth.js)
-- [parallel/test-icu-transcode.js](https://github.com/nodejs/node/tree/v18.12.1/test/parallel/test-icu-transcode.js)
 - [parallel/test-inspect-address-in-use.js](https://github.com/nodejs/node/tree/v18.12.1/test/parallel/test-inspect-address-in-use.js)
 - [parallel/test-inspect-async-hook-setup-at-inspect.js](https://github.com/nodejs/node/tree/v18.12.1/test/parallel/test-inspect-async-hook-setup-at-inspect.js)
 - [parallel/test-inspect-publish-uid.js](https://github.com/nodejs/node/tree/v18.12.1/test/parallel/test-inspect-publish-uid.js)
diff --git a/tests/node_compat/test/parallel/test-icu-transcode.js b/tests/node_compat/test/parallel/test-icu-transcode.js
new file mode 100644
index 000000000..1f5aeb535
--- /dev/null
+++ b/tests/node_compat/test/parallel/test-icu-transcode.js
@@ -0,0 +1,97 @@
+// deno-fmt-ignore-file
+// deno-lint-ignore-file
+
+// Copyright Joyent and Node contributors. All rights reserved. MIT license.
+// Taken from Node 18.12.1
+// This file is automatically generated by `tests/node_compat/runner/setup.ts`. Do not modify this file manually.
+
+'use strict';
+
+const common = require('../common');
+
+if (!common.hasIntl)
+  common.skip('missing Intl');
+
+const buffer = require('buffer');
+const assert = require('assert');
+const orig = Buffer.from('těst ☕', 'utf8');
+
+// Test Transcoding
+const tests = {
+  'latin1': [0x74, 0x3f, 0x73, 0x74, 0x20, 0x3f],
+  'ascii': [0x74, 0x3f, 0x73, 0x74, 0x20, 0x3f],
+  'ucs2': [0x74, 0x00, 0x1b, 0x01, 0x73,
+           0x00, 0x74, 0x00, 0x20, 0x00,
+           0x15, 0x26]
+};
+
+for (const test in tests) {
+  const dest = buffer.transcode(orig, 'utf8', test);
+  assert.strictEqual(dest.length, tests[test].length, `utf8->${test} length`);
+  for (let n = 0; n < tests[test].length; n++)
+    assert.strictEqual(dest[n], tests[test][n], `utf8->${test} char ${n}`);
+}
+
+{
+  const dest = buffer.transcode(Buffer.from(tests.ucs2), 'ucs2', 'utf8');
+  assert.strictEqual(dest.toString(), orig.toString());
+}
+
+{
+  const utf8 = Buffer.from('€'.repeat(4000), 'utf8');
+  const ucs2 = Buffer.from('€'.repeat(4000), 'ucs2');
+  const utf8_to_ucs2 = buffer.transcode(utf8, 'utf8', 'ucs2');
+  const ucs2_to_utf8 = buffer.transcode(ucs2, 'ucs2', 'utf8');
+  assert.deepStrictEqual(utf8, ucs2_to_utf8);
+  assert.deepStrictEqual(ucs2, utf8_to_ucs2);
+  assert.strictEqual(ucs2_to_utf8.toString('utf8'),
+                     utf8_to_ucs2.toString('ucs2'));
+}
+
+assert.throws(
+  () => buffer.transcode(null, 'utf8', 'ascii'),
+  {
+    name: 'TypeError',
+    code: 'ERR_INVALID_ARG_TYPE',
+    message: 'The "source" argument must be an instance of Buffer ' +
+             'or Uint8Array. Received null'
+  }
+);
+
+assert.throws(
+  () => buffer.transcode(Buffer.from('a'), 'b', 'utf8'),
+  /^Error: Unable to transcode Buffer \[U_ILLEGAL_ARGUMENT_ERROR\]/
+);
+
+assert.throws(
+  () => buffer.transcode(Buffer.from('a'), 'uf8', 'b'),
+  /^Error: Unable to transcode Buffer \[U_ILLEGAL_ARGUMENT_ERROR\]$/
+);
+
+assert.deepStrictEqual(
+  buffer.transcode(Buffer.from('hi', 'ascii'), 'ascii', 'utf16le'),
+  Buffer.from('hi', 'utf16le'));
+assert.deepStrictEqual(
+  buffer.transcode(Buffer.from('hi', 'latin1'), 'latin1', 'utf16le'),
+  Buffer.from('hi', 'utf16le'));
+assert.deepStrictEqual(
+  buffer.transcode(Buffer.from('hä', 'latin1'), 'latin1', 'utf16le'),
+  Buffer.from('hä', 'utf16le'));
+
+// Test that Uint8Array arguments are okay.
+{
+  const uint8array = new Uint8Array([...Buffer.from('hä', 'latin1')]);
+  assert.deepStrictEqual(
+    buffer.transcode(uint8array, 'latin1', 'utf16le'),
+    Buffer.from('hä', 'utf16le'));
+}
+
+{
+  const dest = buffer.transcode(new Uint8Array(), 'utf8', 'latin1');
+  assert.strictEqual(dest.length, 0);
+}
+
+// Test that it doesn't crash
+{
+  buffer.transcode(new buffer.SlowBuffer(1), 'utf16le', 'ucs2');
+}