v8/test/mjsunit/es6/block-eval-var-over-let.js
jwolfe d8147eb98c Reland: change most cases of variable redeclaration from TypeError to SyntaxError.
Reland of https://codereview.chromium.org/2048703002/

Code like `let a; eval("var a;");` should throw a SyntaxError, not a TypeError
(this caused a test262 failure.). However, the code `eval("function NaN() {}");`
should actually throw a TypeError. This patch changes most cases of
redeclaration errors from TypeError to SyntaxError. See the test
mjsunit/regress/redeclaration-error-types for a thorough analysis with spec
references.

The relevant sections of the spec are ES#sec-globaldeclarationinstantiation and
ES#sec-evaldeclarationinstantiation

BUG=v8:4955
LOG=y
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
R=adamk

Review-Url: https://codereview.chromium.org/2086063002
Cr-Commit-Position: refs/heads/master@{#37156}
2016-06-21 20:19:59 +00:00

142 lines
2.5 KiB
JavaScript

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Var-let conflict in a function throws, even if the var is in an eval
// Throws at the top level of a function
assertThrows(function() {
let x = 1;
eval('var x');
}, SyntaxError);
// If the eval is in its own block scope, throws
assertThrows(function() {
let y = 1;
{ eval('var y'); }
}, SyntaxError);
// If the let is in its own block scope, with the eval, throws
assertThrows(function() {
{
let x = 1;
eval('var x');
}
}, SyntaxError);
// Legal if the let is no longer visible
assertDoesNotThrow(function() {
{
let x = 1;
}
eval('var x');
});
// All the same works for const:
// Throws at the top level of a function
assertThrows(function() {
const x = 1;
eval('var x');
}, SyntaxError);
// If the eval is in its own block scope, throws
assertThrows(function() {
const y = 1;
{ eval('var y'); }
}, SyntaxError);
// If the const is in its own block scope, with the eval, throws
assertThrows(function() {
{
const x = 1;
eval('var x');
}
}, SyntaxError);
// Legal if the const is no longer visible
assertDoesNotThrow(function() {
{
const x = 1;
}
eval('var x');
});
// In global scope
let caught = false;
try {
let z = 1;
eval('var z');
} catch (e) {
caught = true;
}
assertTrue(caught);
// Let declarations beyond a function boundary don't conflict
caught = false;
try {
let a = 1;
(function() {
eval('var a');
})();
} catch (e) {
caught = true;
}
assertFalse(caught);
// var across with doesn't conflict
caught = false;
try {
(function() {
with ({x: 1}) {
eval("var x");
}
})();
} catch (e) {
caught = true;
}
assertFalse(caught);
// var can still conflict with let across a with
caught = false;
try {
(function() {
let x;
with ({x: 1}) {
eval("var x");
}
})();
} catch (e) {
caught = true;
}
assertTrue(caught);
// Functions declared in eval also conflict
caught = false
try {
(function() {
{
let x = 1;
eval('function x() {}');
}
})();
} catch (e) {
caught = true;
}
assertTrue(caught);
// TODO(littledan): Hoisting x out of the block should be
// prevented in this case BUG(v8:4479)
caught = false
try {
(function() {
{
let x = 1;
eval('{ function x() {} }');
}
})();
} catch (e) {
caught = true;
}
// TODO(littledan): switch to assertTrue when bug is fixed
assertTrue(caught);