Handling byte-order marks as specified in Ecmascript-262 and in compliance wi...

test/mjsunit/bom.js

+// Copyright 2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// According to section 7.1 of EcmaScript-262 format control characters
+// should be removed before parsing. We're following the discussion at
+// https://bugs.webkit.org/show_bug.cgi?id=4931 in only removing the BOM.
+// See also https://bugzilla.mozilla.org/show_bug.cgi?id=274152.
+
+// Ignores BOM (and only BOM) in string literals.
+var format_controls =
+  eval('"\uFEFF\u200F\u200E\u00AD\u2062\u200D\u200C\u200B"');
+assertEquals('\u200F\u200E\u00AD\u2062\u200D\u200C\u200B', 
+             format_controls);
+
+// Ignores BOM in identifiers.
+eval('var x\uFEFFy = 7');
+assertEquals(7, xy);
+
+// Doesn't ignore non-BOM format control characters.
+assertThrows('var y\u200Fx = 7');
+assertThrows('var y\u200Ex = 7');
+assertThrows('var y\u20ADx = 7');
+assertThrows('var y\u2062x = 7');
+assertThrows('var y\u200Dx = 7');
+assertThrows('var y\u200Cx = 7');
+assertThrows('var y\u200Bx = 7');