buffer: add Buffer.fromHex() and Buffer.fromBase64()

lib/buffer.js

@@ -336,6 +336,34 @@
   );
 };
 
+/**
+ * Same as Uint8Array.fromHex(hexstring), but returns instance of Buffer.
+ * Not same as Buffer.from(hexstring), as it performs different validations.
+ * @param {string} str
+ * @returns {Buffer}
+ */
+Buffer.fromHex = function fromHex(str) {
+  const buf = Uint8Array.fromHex(str);
+  return fromArrayBuffer(
+    TypedArrayPrototypeGetBuffer(buf),
+    TypedArrayPrototypeGetByteOffset(buf),
+    TypedArrayPrototypeGetByteLength(buf));
+};
+
+/**
+ * Same as Uint8Array.fromBase64(base64string, options), but returns instance of Buffer.
+ * @param {string} str
+ * @param {object} [options]
+ * @returns {Buffer}
+ */
+Buffer.fromBase64 = function fromBase64(str, options) {
+  const buf = Uint8Array.fromBase64(str, options);
+  return fromArrayBuffer(
+    TypedArrayPrototypeGetBuffer(buf),
+    TypedArrayPrototypeGetByteOffset(buf),
+    TypedArrayPrototypeGetByteLength(buf));
+};
+
 /**
  * Creates the Buffer as a copy of the underlying ArrayBuffer of the view
  * rather than the contents of the view.

test/parallel/test-buffer-fromhex-frombase64.js

@@ -0,0 +1,34 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+const { Buffer } = require('buffer');
+
+assert.deepStrictEqual(Buffer.fromHex('f00dcafe'), Buffer.from('f00dcafe', 'hex'));
+assert.deepStrictEqual(Buffer.fromHex('F00DCAFE'), Buffer.from('f00dcafe', 'hex'));
+assert.deepStrictEqual(Buffer.fromHex(''), Buffer.from('', 'hex'));
+
+assert.throws(() => Buffer.fromHex('0x'), { name: 'SyntaxError' });
+assert.throws(() => Buffer.fromHex('a'), { name: 'SyntaxError' });
+assert.throws(() => Buffer.fromHex(123), { name: 'TypeError' });
+assert.throws(() => Buffer.fromHex('abggcd00'), { name: 'SyntaxError' });
+
+assert.deepStrictEqual(Buffer.fromBase64('SGVsbG8='), Buffer.from('SGVsbG8=', 'base64'));
+assert.deepStrictEqual(Buffer.fromBase64('SGV sbG8='), Buffer.from('SGVsbG8=', 'base64'));
+
+assert.deepStrictEqual(
+  Buffer.fromBase64('PGJsZXA-PC9ibGVwPg', { alphabet: 'base64url' }),
+  Buffer.from('PGJsZXA+PC9ibGVwPg==', 'base64'),
+);
+
+assert.deepStrictEqual(Buffer.fromBase64('SGVsbG8=', { lastChunkHandling: 'strict' }), Buffer.from('Hello'));
+assert.throws(() => Buffer.fromBase64('SGVsbG8', { lastChunkHandling: 'strict' }), { name: 'SyntaxError' });
+
+assert.deepStrictEqual(
+  Buffer.fromBase64('SGVsbG8', { lastChunkHandling: 'stop-before-partial' }),
+  Buffer.from('SGVs', 'base64'),
+);
+
+assert.throws(() => Buffer.fromBase64('SGV$sbG8=', {}), { name: 'SyntaxError' });
+assert.throws(() => Buffer.fromBase64('S', {}), { name: 'SyntaxError' });
+assert.throws(() => Buffer.fromBase64(123), { name: 'TypeError' });
+assert.throws(() => Buffer.fromBase64('SGVsbG8=', { alphabet: 'unknown' }), { name: 'TypeError' });