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.
In Date.parse() and new Date(), representations of the year 0 as -000000
must not be accepted. In the case of Date.parse(), they should yield NaN,
and in the case of new Date(), they should yield an invalid Date object,
whose valueOf() is NaN.
Prior to this commit, the descriptors of the constructor properties of
the global object were verified inconsistently, many independent
assertions occured in the same file, and that file test was poorly
located.
Restructure the relevant tests to improve coverage, follow convention,
and promote discoverability.
The values defined by the referenced files are not used by these tests.
This makes their inclusion superfluous, which needlessly increases the
time to execute the tests and may confuse some readers.
Peter Hoddie
Kevin Gibbons
Philip Chimento
Andreas Woess
rwaldron
Alexey Shvayka
Ross Kirsling
Leo Balter
Mike Pennisi
Richard Gibson
Andrew Paprocki
André Bargull
Viktor
Sue Lockwood
Daniel Ehrenberg
Daniel Ehrenberg