v8/test/mjsunit/global-const-var-conflicts.js
verwaest@chromium.org aa7198dfdd This CL simplifies var / const by ensuring the behavior is consistent in itself, and with regular JS semantics; between regular var/const and eval-ed var/const.
Legacy const is changed so that a declaration declares a configurable, but non-writable, slot, and the initializer reconfigures it (when possible) to non-configurable non-writable. This avoids the need for "the hole" as marker value in JSContextExtensionObjects and GlobalObjects. Undefined is used instead.

BUG=
R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/379893002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22379 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-07-14 14:01:04 +00:00

61 lines
2.8 KiB
JavaScript

// 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.
// Check that dynamically introducing conflicting consts/vars
// is silently ignored (and does not lead to exceptions).
var caught = 0;
eval("const a");
try { eval("var a"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertTrue(typeof a == 'undefined');
try { eval("var a = 1"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertTrue(typeof a == 'undefined');
eval("const b = 0");
try { eval("var b"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertEquals(0, b);
try { eval("var b = 1"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertEquals(0, b);
assertEquals(0, caught);
eval("var c");
try { eval("const c"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertTrue(typeof c == 'undefined');
assertEquals(1, caught);
try { eval("const c = 1"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertEquals(undefined, c);
assertEquals(2, caught);
eval("var d = 0");
try { eval("const d"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertEquals(0, d);
assertEquals(3, caught);
try { eval("const d = 1"); } catch (e) { caught++; assertTrue(e instanceof TypeError); }
assertEquals(0, d);
assertEquals(4, caught);