doc: add readable and writable property to Readable and Writable

[dexterleng]

Issue #21431

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[dexterleng]

ping @jasnell

[Trott]

@nodejs/streams @nodejs/documentation This could use some reviews.

[mcollina]

The default value is slightly different, and the meaning as well. writable is true when it's safe to call write(), and readable is true when it's safe to call read().

The problem is that some of the core and ecosystem streams sets readable or writable to false to take into account a delayed open scenario.

[dexterleng]

The default value is slightly different, and the meaning as well.

@mcollina Could you elaborate? In the constructor of Readable and Writable the properties are both true.

[mcollina]

Check out https://github.com/nodejs/node/blob/master/lib/_stream_duplex.js#L55-L66.

[mcollina]

LGTM

[Trott]

Lite CI: https://ci.nodejs.org/job/node-test-pull-request-lite-pipeline/1669/

[Trott]

Landed in 16a2b5c.

Thanks for the contribution! 🎉

[MylesBorins]

FWIW this landed with REPLACEME tags and subsequently got updated with an 11.x number for when it landed... which is innacurate