pipeThrough() not working in Safari

[kleinph]

When using the CompressionStreams polyfill with Safari like this:

file.stream().pipeThrough(new CompressionStream('gzip'));

the invocation of pipeThrough() fails with readable should be ReadableStream.

The error is thrown after isReadableStream check failed [1]. After debugging I'm sure, that it is failing, because the symbol readableStreamController_ is not defined in the tested value [2].

Note that Safari is also polyfilling the basic streams implemenation, bacause there is no support for BYOB/bytsoures.
Not using the polyfill and instead directly importing CompressionStream from the lib works.

This issue occurs at least on Safari 16.3 and 15.5 and TP.

I made a minimal reproducer in StackBlitz (check console output): https://stackblitz.com/edit/js-gaksqm

1:

sd-streams/packages/streams/src/readable-stream.ts

Line 110 in 009c982

throw new TypeError("readable must be a ReadableStream");

2:

sd-streams/packages/streams/src/readable-internals.ts

Line 201 in c9db3d0

return readableStreamController_ in value;