engine262 VS test262

engine262

Indeed. ECMA-262 has been implemented using JavaScript https://github.com/engine262/engine262.

Node.js is not the only JavaScript runtime. JavaScript runtimes have been written using JavaScript alone, see engine262. There is also Deno, QuickJS, txiki.js, Bun, none of which use COmmonJS by default, SpiderMonkey, et al.

for an interpreted language like JS, this project is really nice https://github.com/engine262/engine262. More or less 2 parts: parser and evaluator

That is a bit complex, so here's a list of JS engines: if you pick one written *in* JS, that would probably be most useful -- engine262 for example

then you might be impressed by https://github.com/engine262/engine262 as well

Engine 262

It's outside of what you asked for, but here's a JavaScript engine in JavaScript. Might make for some interesting bedtime reading!

Interesting to see a JS implementation written in JS:

https://github.com/engine262/engine262/

(The readme explains what the point of it is.)

Indeed. These may be even more important...

https://github.com/tc39/test262

I successfully executed the assert-true.js and assert-false.js tests in the harness folder of the test262 repo. (This folder is full of tests which test the test harness itself.)

I have used a few js engines in the past (nashorn, rhino, otto) and all had problems with missing edge cases in the APIs or really weird quirks in the interop with the host environment.

https://github.com/tc39/test262 is the ecma test suite.

rhino for example has extensive gaps: