Documentation should mention `encoding` instead of `defaultEncoding` as options property for `fs.createWriteStream`

[azasypkin]

• Version: 6.11.1
• Platform: Linux 4.12.3-1-ARCH
• Subsystem: fs

Documentation says that defaultEncoding is the right options property for fs.createWriteStream. But if we look into source code [1] options are directly passed to WriteStream that expects options.encoding [2]. At the same time options are passed to Writable->WritableState [3] that expects options.defaultEncoding instead [4].

For example this inconsistency reveals when you pass "wrong" encoding. Both following examples throw TypeError: Unknown encoding: unknown:

fs.createWriteStream('....', 'unknown');

and

fs.createWriteStream('....', { encoding: 'unknown' });

But the following example doesn't throw anything:

fs.createWriteStream('....', { defaultEncoding: 'unknown' });

I see there was a similar issue a while ago: nodejs/node-v0.x-archive#7710. So at least it's confusing.

[1] https://github.com/nodejs/node/blob/v6.x/lib/fs.js#L2059
[2] https://github.com/nodejs/node/blob/v6.x/lib/fs.js#L2100
[3] https://github.com/nodejs/node/blob/v6.x/lib/fs.js#L2077
[4] https://github.com/nodejs/node/blob/v6.x/lib/_stream_writable.js#L64

[MylesBorins]

/cc @nodejs/streams @mcollina

[mcollina]

I would say we should update the docs to use 'encoding' instead. @azasypkin would you like to send a PR?

[azasypkin]

@azasypkin would you like to send a PR?

Sure, but will go through CONTRIBUTING.md first. Should the fix go to master only or PRs for 6/7/8 will be needed too?

And I'm going to update TS type definitions too (I see it has been noticed already DefinitelyTyped/DefinitelyTyped#14981).

[mcollina]

the fix will go to master, and then we will backport to 8 and 6.