readline: handle wide characters properly

Handle wide characters (such as あ, 谢, 고) as two column wide to make
cursor move properly.

Closes #555.
Closes #4994.

1 files changed, 19 insertions, 0 deletions

diff --git a/test/simple/test-readline-interface.js b/test/simple/test-readline-interface.js
index fc20d1d212..d0bc494c23 100644
--- a/test/simple/test-readline-interface.js
+++ b/test/simple/test-readline-interface.js
@@ -173,6 +173,25 @@ FakeInput.prototype.end = function() {};
   assert.equal(callCount, 1);
   rli.close();
 
+  // wide characters should be treated as two columns.
+  assert.equal(readline.isFullWidthCodePoint('a'.charCodeAt(0)), false);
+  assert.equal(readline.isFullWidthCodePoint('あ'.charCodeAt(0)), true);
+  assert.equal(readline.isFullWidthCodePoint('谢'.charCodeAt(0)), true);
+  assert.equal(readline.isFullWidthCodePoint('고'.charCodeAt(0)), true);
+  assert.equal(readline.isFullWidthCodePoint(0x1f251), true); // surrogate
+  assert.equal(readline.codePointAt('ABC', 0), 0x41);
+  assert.equal(readline.codePointAt('あいう', 1), 0x3044);
+  assert.equal(readline.codePointAt('\ud800\udc00', 0),  // surrogate
+      0x10000);
+  assert.equal(readline.codePointAt('\ud800\udc00A', 2), // surrogate
+      0x41);
+  assert.equal(readline.getStringWidth('abcde'), 5);
+  assert.equal(readline.getStringWidth('古池や'), 6);
+  assert.equal(readline.getStringWidth('ノード.js'), 9);
+  assert.equal(readline.getStringWidth('你好'), 4);
+  assert.equal(readline.getStringWidth('안녕하세요'), 10);
+  assert.equal(readline.getStringWidth('A\ud83c\ude00BC'), 5); // surrogate
+
   assert.deepEqual(fi.listeners('end'), []);
   assert.deepEqual(fi.listeners(terminal ? 'keypress' : 'data'), []);
 });