readline: use a "string_decoder" to parse "keypress" events

While updating the readline test cases to test both "terimal: false" and
"terminal: true" mode, it turned out that the test case testing utf8 chars
being sent over multiple write() calls was failing. The solution is to use
a string_decoder instance when parsing the "keypress" events.

lib/readline.js

@@ -801,12 +801,14 @@ exports.Interface = Interface;
  */
 
 function emitKeypressEvents(stream) {
-  if (stream._emitKeypress) return;
-  stream._emitKeypress = true;
+  if (stream._keypressDecoder) return;
+  var StringDecoder = require('string_decoder').StringDecoder; // lazy load
+  stream._keypressDecoder = new StringDecoder('utf8');
 
   function onData(b) {
     if (stream.listeners('keypress').length > 0) {
-      emitKey(stream, b);
+      var r = stream._keypressDecoder.write(b);
+      if (r) emitKey(stream, r);
     } else {
       // Nobody's watching anyway
       stream.removeListener('data', onData);

test/simple/test-readline-interface.js

@@ -32,14 +32,17 @@ function FakeInput() {
 inherits(FakeInput, EventEmitter);
 FakeInput.prototype.resume = function() {};
 FakeInput.prototype.pause = function() {};
+FakeInput.prototype.write = function() {};
+FakeInput.prototype.end = function() {};
 
+[ true, false ].forEach(function(terminal) {
   var fi;
   var rli;
   var called;
 
   // sending a full line
   fi = new FakeInput();
-rli = new readline.Interface(fi, {});
+  rli = new readline.Interface({ input: fi, output: fi, terminal: terminal });
   called = false;
   rli.on('line', function(line) {
     called = true;
@@ -50,7 +53,7 @@ assert.ok(called);
 
   // sending a blank line
   fi = new FakeInput();
-rli = new readline.Interface(fi, {});
+  rli = new readline.Interface({ input: fi, output: fi, terminal: terminal });
   called = false;
   rli.on('line', function(line) {
     called = true;
@@ -72,7 +75,7 @@ rli.close();
 
   // sending a single character with no newline and then a newline
   fi = new FakeInput();
-rli = new readline.Interface(fi, {});
+  rli = new readline.Interface({ input: fi, output: fi, terminal: terminal });
   called = false;
   rli.on('line', function(line) {
     called = true;
@@ -86,8 +89,8 @@ rli.close();
 
   // sending multiple newlines at once
   fi = new FakeInput();
-rli = new readline.Interface(fi, {});
-var expectedLines = ['foo\n', 'bar\n', 'baz\n'];
+  rli = new readline.Interface({ input: fi, output: fi, terminal: terminal });
+  var expectedLines = ['foo', 'bar', 'baz'];
   var callCount = 0;
   rli.on('line', function(line) {
     assert.equal(line, expectedLines[callCount]);
@@ -99,9 +102,9 @@ rli.close();
 
   // sending multiple newlines at once that does not end with a new line
   fi = new FakeInput();
-rli = new readline.Interface(fi, {});
-var expectedLines = ['foo\n', 'bar\n', 'baz\n', 'bat'];
-var callCount = 0;
+  rli = new readline.Interface({ input: fi, output: fi, terminal: terminal });
+  expectedLines = ['foo', 'bar', 'baz', 'bat'];
+  callCount = 0;
   rli.on('line', function(line) {
     assert.equal(line, expectedLines[callCount]);
     callCount++;
@@ -113,7 +116,7 @@ rli.close();
   // sending a multi-byte utf8 char over multiple writes
   var buf = Buffer('☮', 'utf8');
   fi = new FakeInput();
-rli = new readline.Interface(fi, {});
+  rli = new readline.Interface({ input: fi, output: fi, terminal: terminal });
   callCount = 0;
   rli.on('line', function(line) {
     callCount++;
@@ -128,4 +131,5 @@ assert.equal(callCount, 1);
   rli.close();
 
   assert.deepEqual(fi.listeners('end'), []);
-assert.deepEqual(fi.listeners('data'), []);
+  assert.deepEqual(fi.listeners(terminal ? 'keypress' : 'data'), []);
+});