Assert that ImportDeclaration and ExportDeclaration match only the
ModuleItem symbol.
According to the definition of HostResolveImportedModule, it is
acceptable for an implementation to throw a SyntaxError in the event
that a requested module can neither be found nor created:
> If a Module Record corresponding to the pair referencingModule,
> specifier does not exist or cannot be created, an exception must be
> thrown.
In order to reliably detect a SyntaxError in response to the correct
interpretation of the grammar (and not a SyntaxError from an *incorrect*
interpretation of the grammar followed by a failure to resolve the
requested module), the ModuleSpecifier of ExportDeclarations should
describe a valid resource.
- Prefix file names to explicitly describe the "head" position
- Remove statement name suffix as this information is reflected by each
file's location within the file hierarchy
The harness file `Test262Error.js` has not contained executable code since it
was introduced in this project [1]. The definition of the `Test262Error`
function has consistently been located in the `sta.js` harness file which test
runners are expected to inject into the test environment.
Remove the file and all references to it.
[1] See commit c33bf0e043
For asynchronous tests, the contract between test file and test runner
is implicit: runners are expected to inspect the source code for
references to a global `$DONE` identifier.
Promote a more explicit contract between test file and test runner by
introducing a new frontmatter "tag", `async`. This brings asynchronous
test configuration in-line with other configuration mechanisms and also
provides a more natural means of test filtering.
The modifications to test files was made programatically using the
`grep` and `sed` utilities:
$ grep "\$DONE" test/ -r --files-with-match --null | \
xargs -0 sed -i 's/^\(flags:\s*\)\[/\1[async, /g'
$ grep "\$DONE" test/ -rl --null | \
xargs -0 grep -E '^flags:' --files-without-match --null | \
xargs -0 sed -i 's/^---\*\//flags: [async]\n---*\//'
When executing multiple tests in parallel, each "child" thread would
write to the process's standard output buffer immediately upon test
completion. Because thread execution order and instruction interleaving
is non-deterministic, this made it possible for characters to be emitted
out-of-order.
When extended to support multiple concurrent threads, the runner was
outfitted with a "log lock" dedicated to sharing access to the output
file (when applicable). Re-use this lock when writing to standard out,
ensuring proper ordering of test result messages.
A recent extension to the test runner introduced support for running
tests in parallel using multi-threading. Following this, the runner
would incorrectly emit the "final report" before all individual test
results.
In order to emit the "final report" at the end of the output stream, the
parent thread would initialize all children and wait for availability of
a "log lock" shared by all children.
According to the documentation on the "threading" module's Lock object
[1]:
> When more than one thread is blocked in acquire() waiting for the state
> to turn to unlocked, only one thread proceeds when a release() call
> resets the state to unlocked; which one of the waiting threads proceeds
> is not defined, and may vary across implementations.
This means the primitive cannot be used by the parent thread to reliably
detect completion of all child threads.
Update the parent to maintain a reference for each child thread, and to
explicitly wait for every child thread to complete before emitting the
final result.
[1] https://docs.python.org/2/library/threading.html#lock-objects
Assert that the `constructor` property of the "this" value of
`Promise.prototype.then` is accessed exactly once. This guards against
implementations where repeated access is used instead of reference
passing (possibly motivated by convenience).
Repeated access of this kind was demonstrated by V8's implementation of
the specification:
https://bugs.chromium.org/p/v8/issues/detail?id=4539
Add tests that assert behavior when a Promise is resolved with another
Promise whose `then` method has been overridden. Because all objects
with a `then` method are treated equivalently, the presence of a
[[PromiseState]] internal slot should have no effect on program
behavior.
These tests guard against a faulty optimization originally implemented
in V8:
https://bugs.chromium.org/p/v8/issues/detail?id=3641
The "mainline" tests in Test262 are converging on a more formal
structure. Files are organized as tests for either either "language"
(e.g. syntax-driven) or "built-in" (e.g. API-driven). "Language" test
locations are themselves structured according to whether the syntactic
form under test is an Expression or a Statement.
To limit ambiguity when locating/adding tests, re-organize the tests for
Annex B extensions to match this structure.
Rick Waldron
Leonardo Balter
Gorkem Yakin
Mike Pennisi
Jordan Harband
André Bargull