fs.promises API is working but why

[fxdave]

• Version: v10.15.0
• Platform: Linux dbiro 4.20.0-arch1-1-ARCH deps: update openssl to 1.0.1j #1 SMP PREEMPT Mon Dec 24 03:00:40 UTC 2018 x86_64 GNU/Linux
• Subsystem: filesystem

Details:

electron-userland/electron-webpack#255

In short:

Here it is the implementation of getOptions:

function getOptions(options, defaultOptions) {
  if (options === null || options === undefined ||
      typeof options === 'function') {
    return defaultOptions;
  }

  if (typeof options === 'string') {
    defaultOptions = util._extend({}, defaultOptions);
    defaultOptions.encoding = options;
    options = defaultOptions;
  } else if (typeof options !== 'object') {
    throw new ERR_INVALID_ARG_TYPE('options', ['string', 'Object'], options);
  }

  if (options.encoding !== 'buffer')
    assertEncoding(options.encoding);
  return options;
}

But this code is working:

const fsp = require('fs')
fsp.readFile(SOME_VALID_URL, { encoding: 'utf8' })

[cjihrig]

Are you asking why that code works as expected in Node, but not in electron-webpack? If so, you'd have to take that up with the electron-webpack team.

[fxdave]

@cjihrig This code shouldn't work based on the "getOptions" function.

The expected behavior is to throw :

TypeError [ERR_INVALID_OPT_VALUE]: The value "undefined" is invalid for option "flags"
      at stringToFlags (internal/fs/utils.js:253:9)
      at open (internal/fs/promises.js:198:34)
      at Object.readFile (internal/fs/promises.js:466:20)
      ...

Because the object { encoding: 'utf8' } is not containing the flag attribute.
I think it is the getOptions' job, to put the non-optional 'flag' to the given object.

I got the code from the v10.15.0-proposal branch.
But if it is not a node issue, I close it.

[richardlau]

@cjihrig This code shouldn't work based on the "getOptions" function.

The expected behavior is to throw :

TypeError [ERR_INVALID_OPT_VALUE]: The value "undefined" is invalid for option "flags"
      at stringToFlags (internal/fs/utils.js:253:9)
      at open (internal/fs/promises.js:198:34)
      at Object.readFile (internal/fs/promises.js:466:20)
      ...

Because the object { encoding: 'utf8' } is not containing the flag attribute.
I think it is the getOptions' job, to put the non-optional 'flag' to the given object.

I got the code from the v10.15.0-proposal branch.
But if it is not a node issue, I close it.

Wasn't this fixed by #20268?

[fxdave]

@richardlau You are right, then I got wrong source from debugger. Closing it.