This PR proposes changes to existing test262 tests to allow them to pass under Hardened JavaScript (see Secure ECMAScript proposal and Hardened JavaScript). Moddable uses Hardened JavaScript for JavaScript runtimes on resource constrained embedded devices, including those targeted by ECMA-419.
The changes fall into four groups:
1. Replace use of new Date() with new Date(1970). Scripts running inside a Compartment cannot retrieve the current time, so new Date() throws but new Date(1970) succeeds. Very few tests need the current time, but instead simply need a Date instance.
2. Use Object.defineProperty instead of setting existing built-in properties directly, such as toString and toValue. In Hardened JavaScript, prototypes of built-in objects are frozen. Consequently, setting properties of an instance that exist on the prototype throw (Hardened JavaScript is always in strict mode).
3. Eliminate use of Math.random(). Scripts running inside a Compartment cannot generate random numbers. One test identified so far uses Math.random() in a way that can easily be replaced with a counter.
4. Narrow the scope of exception tests. Consider the following
assert.throws(TypeError, () => {
var s1 = new Date();
s1.toString = Boolean.prototype.toString;
s1.toString();
});
This test passes, but only because new Date() fails by throwing a TypeError. If the invocation of the Date constructor is resolved by (1) above, then the assignment to toString fails as per (2) above. The script should be modified as below to ensure that assert.throws only tests the intended statement, s1.toString(). The modified script tests the intended functionality and passes under Hardened JavaScript
var s1 = new Date(1970);
Object.defineProperty(s1, "toString", {
value: Boolean.prototype.toString
});
assert.throws(TypeError, () => {
s1.toString();
});
This is an initial PR to begin the process of adapting test262 for use with Hardened JavaScript. Further changes are expected, with the vast majority likely to fall into the four groups described above.
Thank you to gibson042, kriskowal, and erights for their advice on this work.
* Reject exceptional input to `isConstructor`
Prior to this commit, the `isConstructor` harness function would return
`false` when invoked with a value that lacked a [[Call]] internal
method. While it's true that such values are not constructors, there are
no tests which benefit from using `isConstructor` to make such an
assertion.
Extend `isConstructor` to throw an error when invoked with a
non-function object. Update a test which was misleadingly invoking the
function with the value `undefined`.
* fixup! Reject exceptional input to `isConstructor`
Includes key should use flow notation to be able parsed easier
as suggested in https://github.com/tc39/test262/issues/1997
Added this check to the linting script and updated tests accordingly.
The `compareArray` utility function returns a boolean value describing
whether or not the input arrays are equivalent--it does not throw an
exception when invoked with non-equivalent arrays. Prior to this commit,
however, two tests invoked `compareArray` without inspecting its return
value, so it had no impact on the result of the test.
Update the tests to fail when the "expected" and "actual" arrays are not
equivalent.
This reverts commit b690cb67be, reversing
changes made to 50dd431dff. This is
necessary because the reverted changeset reduced coverage by an unknown
extent.
These tests were designed to test the built-in "Promise.race Resolve
Element function," but ECMA262 does not describe such a function.
Contrary to the test's description, the function under test is created
by the InstantiateArrowFunctionExpression abstract operation. The
following tests verify most of the details directly (only the function
object's extensibility was not already tested by the existing tests):
- test/language/expressions/arrow-function/name.js
- test/language/expressions/arrow-function/throw-new.js
- test/language/expressions/arrow-function/prototype-rules.js
The definition of the built-in resolving functions is closely related,
but Test262 already includes tests for the corresponding concerns:
- test/built-ins/Promise/resolve-function-extensible.js
- test/built-ins/Promise/resolve-function-name.js
- test/built-ins/Promise/resolve-function-nonconstructor.js
- test/built-ins/Promise/resolve-function-prototype.js
Remove the tests and introduce one additional test to preserve coverage
while improving discoverability.
Meghan Denny
Peter Hoddie
Timothy Flynn
Jordan Harband
Sosuke Suzuki
Kevin Gibbons
Peter Klecha
Peter Klecha
jugglinmike
Csaba Osztrogonác
rwaldron
ExE Boss
Alexey Shvayka
Gus Caplan
André Bargull