outputJson does not preserve the object for asynchronous processing

[paragi]

• Operating System: Linux 4.15.0-52 Debian
• Node.js version: 12.2.0
• fs-extra version:8.1.0

When writing object asynchronously with outputJson, the object is not preserved, before the promise is returned.

Example:

const fs = require('fs-extra');

( async () => {
  let i;
  let obj = {}
  let promises = [];

  for( i = 0; i<4; i++ ){
    obj.id = i;
    promises.push( fs.outputJson('./' + i, obj) );
  }

  await Promise.all(promises);

  for( i = 0; i<4; i++ )
    console.log( await fs.readJson('./' + i));

})();

[RyanZim]

Yes, this is normal. If you're mutating an object, behavior will not be predictable.

[paragi]

In most asynchronous use cases i can imagine, you would want to use the stringification, to preserve the object, instead of copying it first (closure), then stringify it and then dumping it.

In my opinion, it seems contra intuitive, and sort of defeats the purpose, of having a function to replace fs.outputFile(fileName, JSON.stringify(object) )

I wish you would reconsider.

[RyanZim]

How does writeJson work here?

[paragi]

writeJson seems to be asynchronous mutation safe