test/mjsunit/harmony/block-let-declaration.js

// Copyright 2011 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.

// Flags: --harmony-block-scoping

// Test let declarations in various settings.

// Global
let x;
let y = 2;

// Block local
{
  let y;
  let x = 3;
}

assertEquals(undefined, x);
assertEquals(2,y);

if (true) {
  let y;
  assertEquals(undefined, y);
}

function TestLocalThrows(str, expect) {
  assertThrows("(function(){" + str + "})()", expect);
}

function TestLocalDoesNotThrow(str) {
  assertDoesNotThrow("(function(){" + str + "})()");
}

// Unprotected statement
TestLocalThrows("if (true) let x;", SyntaxError);
TestLocalThrows("with ({}) let x;", SyntaxError);
TestLocalThrows("do let x; while (false)", SyntaxError);
TestLocalThrows("while (false) let x;", SyntaxError);

TestLocalDoesNotThrow("if (true) var x;");
TestLocalDoesNotThrow("with ({}) var x;");
TestLocalDoesNotThrow("do var x; while (false)");
TestLocalDoesNotThrow("while (false) var x;");