ShadowRealms WPT Problems

[mgaudet]

Here are some issues I've seen in the ShadowRealms WPT that -might- be implementation specific, but I'd be curious about feedback from other implementations running tests:

• In the WASM tests I am noticing a lot of test failures related to undefined references. For example in the wasm tests, lots of failures of the shape assert_Table is not defined, -- it is as if `// META: script=/wasm/jsapi/table/assertions.js is being ignored, but I can't fathom why.
• The encoding backpressure tests fail, but only in shadow realms?

[caridy]

/cc @rwaldron

[rwaldron]

The failures around undefined references are caused by those external script resources not being loaded into the ShadowRealm created for the test. That's not an "issue" with ShadowRealms or testing of ShadowRealms, it's just a bug in the test harness that needs to be fixed.

[rwaldron]

The reason assert_Memory is undefined is because it needs to be set as globalThis.assert_Memory = ... in wasm/jsapi/memory/assertions.js

[rwaldron]

As for the encoding back pressure issues, I can't say why that doesn't work—it looks like the outcomes are out of order? There's nothing about ShadowRealm itself that would cause that. I wanted to try running that test in either of the other implementations, but couldn't get my local runner to pick up the /encoding/streams/backpressure.any.shadowrealm.html test, even though it is definitely in the manifest 🤷