@js-temporal/temporal-test262-runner

Lightweight runner for ECMAScript Temporal's Test262 tests

This package provides a fast way for polyfills of ECMAScript Temporal to run Temporal's 6,300+ Test262 tests. Test262 (https://github.com/tc39/test262) is the official conformance test suite for ECMAScript, and this package quickly runs a subset of those tests that are specific to Temporal. All Temporal polyfills should pass Test262.

This runner is much faster than test262-harness (the default Test262 harness) because:

• It runs only 6,300+ Temporal-specific tests, instead of the full suite.
• It pre-parses the Temporal polyfill into a vm.Script, instead of reading and parsing the whole file once for each test like the prelude option of test262-harness does. This causes tests to run at least 10x faster.

A typical run of all 6300+ Temporal tests will finish in less than 30 seconds.

For code coverage, set the environment variable NODE_V8_COVERAGE to the path (relative to the working directory) where coverage metrics should be output. These can be processed with the c8 tool. NOTE: as of Node 18.7 there is a memory leak that makes it impossible to run the entire suite with NODE_V8_COVERAGE, so for code coverage tests you should run it in chunks.

Example Usage

import runTest262 from 'temporal-test262-runner';

const result = runTest262({
  test262Dir: 'test262',
  polyfillCodeFile: 'dist/script.js',
  expectedFailureFiles: ['test/expected-failures.txt'],
  testGlobs: process.argv.slice(2)
});

// if result is `true`, all tests succeeded
process.exit(result ? 0 : 1);

Options

• polyfillCodeFile: string - Filename of the Temporal polyfill. Must be a single ECMAScript file that contains the Temporal object injected into the global namespace, as well as Temporal-related changes polyfilled into Intl and Date built-in objects.
• test262Dir: string - Root directory of the test262 submodule repo.
• testGlobs?: string[] - If omitted, all Temporal tests will be run. This option provides glob patterns that specify a subset of tests to be run. Globs are resolved relative to test/**/Temporal/ subdirectories of test262Dir. If a pattern doesn't match any files relative to test/**/Temporal/, it will also try to match relative to the current working directory, so that tab completion works. Example: [ 'PlainDateTime/**', 'prototype/with/*.js' ]
• expectedFailureFiles?: string[] Optional array of text filenames that each contain a list of test files (relative to the test subdirectory of test262Dir) that are expected to fail. Lines starting with # and blank lines are ignored. Lines from multiple files will be concatenated and de-duped. Example:

  # https://github.com/tc39/test262/pull/3548
  built-ins/Temporal/Duration/compare/argument-string-negative-fractional-units.js
  built-ins/Temporal/Duration/from/argument-string-negative-fractional-units.js
  

Changelog

0.8.0

• Make npm test fail when tests pass unexpectedly (#6)