buffer: optimize hex_decode

PR-URL: https://github.com/nodejs/node/pull/7602
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 43 insertions, 0 deletions

diff --git a/test/parallel/test-buffer-badhex.js b/test/parallel/test-buffer-badhex.js
new file mode 100644
index 0000000000..3611ba3a09
--- /dev/null
+++ b/test/parallel/test-buffer-badhex.js
@@ -0,0 +1,43 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+const Buffer = require('buffer').Buffer;
+
+// Test hex strings and bad hex strings
+{
+  const buf1 = Buffer.alloc(4);
+  assert.strictEqual(buf1.length, 4);
+  assert.deepStrictEqual(buf1, new Buffer([0, 0, 0, 0]));
+  assert.strictEqual(buf1.write('abcdxx', 0, 'hex'), 2);
+  assert.deepStrictEqual(buf1, new Buffer([0xab, 0xcd, 0x00, 0x00]));
+  assert.strictEqual(buf1.toString('hex'), 'abcd0000');
+  assert.strictEqual(buf1.write('abcdef01', 0, 'hex'), 4);
+  assert.deepStrictEqual(buf1, new Buffer([0xab, 0xcd, 0xef, 0x01]));
+  assert.strictEqual(buf1.toString('hex'), 'abcdef01');
+
+  const buf2 = Buffer.from(buf1.toString('hex'), 'hex');
+  assert.strictEqual(buf1.toString('hex'), buf2.toString('hex'));
+
+  const buf3 = Buffer.alloc(5);
+  assert.strictEqual(buf3.write('abcdxx', 1, 'hex'), 2);
+  assert.strictEqual(buf3.toString('hex'), '00abcd0000');
+
+  const buf4 = Buffer.alloc(4);
+  assert.deepStrictEqual(buf4, new Buffer([0, 0, 0, 0]));
+  assert.strictEqual(buf4.write('xxabcd', 0, 'hex'), 0);
+  assert.deepStrictEqual(buf4, new Buffer([0, 0, 0, 0]));
+  assert.strictEqual(buf4.write('xxab', 1, 'hex'), 0);
+  assert.deepStrictEqual(buf4, new Buffer([0, 0, 0, 0]));
+  assert.strictEqual(buf4.write('cdxxab', 0, 'hex'), 1);
+  assert.deepStrictEqual(buf4, new Buffer([0xcd, 0, 0, 0]));
+
+  const buf5 = Buffer.alloc(256);
+  for (let i = 0; i < 256; i++)
+    buf5[i] = i;
+
+  const hex = buf5.toString('hex');
+  assert.deepStrictEqual(Buffer.from(hex, 'hex'), buf5);
+
+  const badHex = hex.slice(0, 256) + 'xx' + hex.slice(256, 510);
+  assert.deepStrictEqual(Buffer.from(badHex, 'hex'), buf5.slice(0, 128));
+}