Re: [whatwg/streams] Support transferable streams (postMessage) (#1053)

@domenic commented on this pull request.



> +
+ <p class="note">As we are already in an errored state when this abstract operation is performed, we
+ cannot handle further errors, so we just discard them.</p>
+
+</div>
+
+<div algorithm>
+ <dfn abstract-op lt="SetUpCrossRealmTransformReadable">SetUpCrossRealmTransformReadable(|stream|,
+ |port|)</dfn> performs the following steps:
+
+ 1. Perform ! [$InitializeReadableStream$](|stream|).
+ 1. Let |controller| be a [=new=] {{ReadableStreamDefaultController}}.
+ 1. Let |backpressurePromise| be [=a new promise=].
+ 1. Add a handler for |port|'s {{MessagePort/message}} event with the following steps:
+  1. Let |data| be the data of the message.
+  1. If ! [$Type$](|data|) is not Object, return.

I'd suggest an assert then. You could add a general note saying something about how assertions (either "assert" or !) could fail in memory-corruption scenarios (including security exploits), although that kind of holds for all asserts in the spec, so maybe it's not necessary.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/streams/pull/1053#discussion_r452548002