About This Project

Test262 Report is a tool for people who write JavaScript programs for web browsers and node.js to learn about implementation interoperability. This report is backed by comprehensive specification-conformance tests. This data-driven approach to interoperability reporting sets Test262 Report apart from traditional compatibility tables.

We developed Test262 Report at Bocoup to report on our work testing web platform features. We are run JavaScript conformance tests against five major JavaScript implementations: ChakraCore, JavaScriptCore, Moddable XS, SpiderMonkey and V8.

Source and documentation

The official JavaScript specification, ECMA-262 is a standard produced by Technical Committee #39 (TC39) at the Ecma International standards group. The official conformance test suite is called Test262, defined in ECMA TR/104. Test262 contains the material we use to generate the JavaScript Engine results, and is available at https://github.com/tc39/test262.

Test262 Report checks for changes to Test262 and each engine every day. If Test262 changes, all engines are rerun through the new version of Test262. If one engine changes, only that engine is run through test262. If no engines change and Test262 does not change, no new runs are made.

We run Test262 test material via Test262-harness, which itself uses eshost to normalize host runtime environment disparities. We use esvu to install the latest engine binaries.

We collect these results using a set of routines that we developed at Bocoup. If you'd like to report a bug or request a feature, please use our issue tracker.

Licensing and Contact

The source code for the tools used to run Test262 test material across multiple engines is publicly available, free to use, and maintained by the Bocoup team. The systems for orchestrating these tools in CI for daily runs, the data produced by this system, and the Test262 Report website are internal to Bocoup. If you would like to incorporate the conformance data that we collect, or use these systems in some other way, please email reports@bocoup.com.