| // for-of works on strings and String objects. |
| |
| load(libdir + "string.js"); |
| |
| function test(s, expectedCodePoints) { |
| var copy = ''; |
| var codepoints = 0; |
| var singleHighSurrogate = false; |
| for (var v of s) { |
| assertEq(typeof v, 'string'); |
| assertEq(v.length, isSurrogatePair(v) ? 2 : 1); |
| assertEq(false, singleHighSurrogate && isLowSurrogate(v)); |
| copy += v; |
| codepoints += 1; |
| singleHighSurrogate = !isSurrogatePair(v) && isHighSurrogate(v); |
| } |
| assertEq(copy, String(s)); |
| assertEq(codepoints, expectedCodePoints); |
| } |
| |
| test('', 0); |
| test('abc', 3); |
| test('a \0 \ufffe \ufeff', 7); |
| |
| // Non-BMP characters are generally passed to JS in UTF-16, as surrogate pairs. |
| // ES6 requires that such pairs be treated as a single code point in for-of. |
| test('\ud808\udf45', 1); |
| |
| // Also test invalid surrogate pairs: |
| // (1) High surrogate not followed by low surrogate |
| test('\ud808', 1); |
| test('\ud808\u0000', 2); |
| // (2) Low surrogate not preceded by high surrogate |
| test('\udf45', 1); |
| test('\u0000\udf45', 2); |
| // (3) Low surrogate followed by high surrogate |
| test('\udf45\ud808', 2); |
| |
| test(new String(''), 0); |
| test(new String('abc'), 3); |
| test(new String('a \0 \ufffe \ufeff'), 7); |
| test(new String('\ud808\udf45'), 1); |
| test(new String('\ud808'), 1); |
| test(new String('\ud808\u0000'), 2); |
| test(new String('\udf45'), 1); |
| test(new String('\u0000\udf45'), 2); |
| test(new String('\udf45\ud808'), 2); |