Test262 Support for V8

Google wanted to make sure the official test suite for the JavaScript language was up-to-date with the latest standard version, which was set to be published in a few months. Although the language was approaching finalization, it was still undergoing revision with only partial implementation. Extending coverage for a moving target would involve careful planning, thorough specification review, engagement with specification authors, collaboration with language implementors, extensive documentation, and (of course) a whole lot of test writing.

We collaborated with the Google Chrome V8 JavaScript engine team to assess the existing level of coverage, prioritize features, migrate test from the internal V8 test suite, extend the official test harness, restructure test organization, and (of course) write a whole lot of new tests providing a comprehensive coverage for the ES2015 and ES2016 versions of the standard. We continue to work on ES2017 and even ES2018+ features as part of our ongoing work with the V8 team.