test: add comprehensive Buffer.byteLength() tests

Previously, there were very few direct tests for Buffer.byteLength(). I
realized I had introduced some breaking changes in nodejs#1713 that the tests
didn't catch, so I've pretty much added almost every possible corner of
the code here.

It also takes any other byteLength tests from test-buffer and moves
them.

test/parallel/test-buffer-bytelength.js

@@ -0,0 +1,45 @@
+var common = require('../common');
+var assert = require('assert');
+var Buffer = require('buffer').Buffer;
+
+// coerce values to string
+assert.equal(Buffer.byteLength(32, 'raw'), 2);
+assert.equal(Buffer.byteLength(NaN, 'utf8'), 3);
+assert.equal(Buffer.byteLength({}, 'raws'), 15);
+assert.equal(Buffer.byteLength(), 9);
+
+// special case: zero length string
+assert.equal(Buffer.byteLength('', 'ascii'), 0);
+assert.equal(Buffer.byteLength('', 'HeX'), 0);
+
+// utf8
+assert.equal(Buffer.byteLength('∑éllö wørl∂!', 'utf-8'), 19);
+assert.equal(Buffer.byteLength('κλμνξο', 'utf8'), 12);
+assert.equal(Buffer.byteLength('挵挶挷挸挹', 'utf-8'), 15);
+assert.equal(Buffer.byteLength('𠝹𠱓𠱸', 'UTF8'), 12);
+// without an encoding, utf8 should be assumed
+assert.equal(Buffer.byteLength('hey there'), 9);
+assert.equal(Buffer.byteLength('𠱸挶νξ#xx :)'), 17);
+assert.equal(Buffer.byteLength('hello world', ''), 11);
+// it should also be assumed with unrecognized encoding
+assert.equal(Buffer.byteLength('hello world', 'abc'), 11);
+assert.equal(Buffer.byteLength('ßœ∑≈', 'unkn0wn enc0ding'), 10);
+
+// base64
+assert.equal(Buffer.byteLength('aGVsbG8gd29ybGQ=', 'base64'), 11);
+assert.equal(Buffer.byteLength('bm9kZS5qcyByb2NrcyE=', 'base64'), 14);
+assert.equal(Buffer.byteLength('aGkk', 'base64'), 3);
+assert.equal(Buffer.byteLength('bHNrZGZsa3NqZmtsc2xrZmFqc2RsZmtqcw==', 'base64'), 25);
+// special padding
+assert.equal(Buffer.byteLength('aaa=', 'base64'), 2);
+assert.equal(Buffer.byteLength('aaaa==', 'base64'), 3);
+assert.equal(Buffer.byteLength('abcd===', 'base64'), 4);
+assert.equal(Buffer.byteLength('abcd=====', 'base64'), 5);
+
+assert.equal(Buffer.byteLength('Il était tué'), 14);
+assert.equal(Buffer.byteLength('Il était tué', 'utf8'), 14);
+assert.equal(Buffer.byteLength('Il était tué', 'ascii'), 12);
+assert.equal(Buffer.byteLength('Il était tué', 'binary'), 12);
+['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach(function(encoding) {
+  assert.equal(24, Buffer.byteLength('Il était tué', encoding));
+});

test/parallel/test-buffer.js

@@ -560,15 +560,6 @@ assert.equal(sb, s);
 b = new Buffer('abcde');
 assert.equal('bcde', b.slice(1).toString());
 
-// byte length
-assert.equal(14, Buffer.byteLength('Il était tué'));
-assert.equal(14, Buffer.byteLength('Il était tué', 'utf8'));
-['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach(function(encoding) {
-  assert.equal(24, Buffer.byteLength('Il était tué', encoding));
-});
-assert.equal(12, Buffer.byteLength('Il était tué', 'ascii'));
-assert.equal(12, Buffer.byteLength('Il était tué', 'binary'));
-
 // slice(0,0).length === 0
 assert.equal(0, Buffer('hello').slice(0, 0).length);
 
@@ -1073,10 +1064,6 @@ assert.equal(buf.readInt8(0), -1);
   assert.ok(typeof Buffer(5).slice(0, 5).parent === 'object');
 })();
 
-// Make sure byteLength properly checks for base64 padding
-assert.equal(Buffer.byteLength('aaa=', 'base64'), 2);
-assert.equal(Buffer.byteLength('aaaa==', 'base64'), 3);
-
 // Regression test for #5482: should throw but not assert in C++ land.
 assert.throws(function() {
   Buffer('', 'buffer');