Revert "readline: allow tabs in input"

This reverts commit 4b3d493c4b.

PR-URL: https://github.com/nodejs/io.js/pull/1961
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yosuke Furukawa <yosuke.furukawa@gmail.com>

lib/readline.js

@@ -48,7 +48,9 @@ function Interface(input, output, completer, terminal) {
   }
   historySize = historySize || kHistorySize;
 
-  if (completer && typeof completer !== 'function') {
+  completer = completer || function() { return []; };
+
+  if (typeof completer !== 'function') {
     throw new TypeError('Argument \'completer\' must be a function');
   }
 
@@ -71,11 +73,9 @@ function Interface(input, output, completer, terminal) {
   this.historySize = historySize;
 
   // Check arity, 2 - for async, 1 for sync
-  if (typeof completer === 'function') {
-    this.completer = completer.length === 2 ? completer : function(v, cb) {
-      cb(null, completer(v));
-    };
-  }
+  this.completer = completer.length === 2 ? completer : function(v, callback) {
+    callback(null, completer(v));
+  };
 
   this.setPrompt('> ');
 
@@ -345,6 +345,9 @@ Interface.prototype._normalWrite = function(b) {
 };
 
 Interface.prototype._insertString = function(c) {
+  //BUG: Problem when adding tabs with following content.
+  //     Perhaps the bug is in _refreshLine(). Not sure.
+  //     A hack would be to insert spaces instead of literal '\t'.
   if (this.cursor < this.line.length) {
     var beg = this.line.slice(0, this.cursor);
     var end = this.line.slice(this.cursor, this.line.length);
@@ -837,6 +840,10 @@ Interface.prototype._ttyWrite = function(s, key) {
         this._deleteRight();
         break;
 
+      case 'tab': // tab completion
+        this._tabComplete();
+        break;
+
       case 'left':
         this._moveCursor(-1);
         break;
@@ -861,14 +868,6 @@ Interface.prototype._ttyWrite = function(s, key) {
         this._historyNext();
         break;
 
-      case 'tab':
-        // If tab completion enabled, do that...
-        if (typeof this.completer === 'function') {
-          this._tabComplete();
-          break;
-        }
-        // falls through
-
       default:
         if (s instanceof Buffer)
           s = s.toString('utf-8');

test/parallel/test-readline-interface.js

@@ -175,59 +175,6 @@ function isWarned(emitter) {
   assert.equal(callCount, expectedLines.length);
   rli.close();
 
-  // \t when there is no completer function should behave like an ordinary
-  //   character
-  fi = new FakeInput();
-  rli = new readline.Interface({ input: fi, output: fi, terminal: true });
-  called = false;
-  rli.on('line', function(line) {
-    assert.equal(line, '\t');
-    assert.strictEqual(called, false);
-    called = true;
-  });
-  fi.emit('data', '\t');
-  fi.emit('data', '\n');
-  assert.ok(called);
-  rli.close();
-
-  // \t does not become part of the input when there is a completer function
-  fi = new FakeInput();
-  var completer = function(line) {
-    return [[], line];
-  };
-  rli = new readline.Interface({
-    input: fi,
-    output: fi,
-    terminal: true,
-    completer: completer
-  });
-  called = false;
-  rli.on('line', function(line) {
-    assert.equal(line, 'foo');
-    assert.strictEqual(called, false);
-    called = true;
-  });
-  fi.emit('data', '\tfo\to\t');
-  fi.emit('data', '\n');
-  assert.ok(called);
-  rli.close();
-
-  // constructor throws if completer is not a function or undefined
-  fi = new FakeInput();
-  assert.throws(function() {
-    readline.createInterface({
-      input: fi,
-      completer: 'string is not valid'
-    });
-  }, function(err) {
-    if (err instanceof TypeError) {
-      if (/Argument \'completer\' must be a function/.test(err)) {
-        return true;
-      }
-    }
-    return false;
-  });
-
   // sending a multi-byte utf8 char over multiple writes
   var buf = Buffer('☮', 'utf8');
   fi = new FakeInput();