Async custom processors

[johnnyreilly]

Hello!

I've been reading about custom processors:

Using custom processors

For advanced usage where complex processing is needed it's possible to use a callback that will receive content as an argument and should return it processed.

const results = await replaceInFile({
  files: 'path/to/files/*.html',
  processor: (input) => input.replace(/foo/g, 'bar'),
})

The custom processor will receive the path of the file being processed as a second parameter:

const results = await replaceInFile({
  files: 'path/to/files/*.html',
  processor: (input, file) => input.replace(/foo/g, file),
})

Custom processors are great, and very powerful!

However, imagine the scenario where you want to drive the output of a processor from an asynchronous API, based upon the contents of the text file. At present, you can't use custom processors for that scenario as they are synchronous.

What do you think about having an asynchronous custom processors API as well? Something like this say:

const results = await replaceInFile({
  files: 'path/to/files/*.html',
  processorAsync: async (input, file) => { 
    const asyncResult = await doAsyncOperation(input, file);
    return input.replace(/foo/g, asyncResult) 
  },
})

[adamreisnz]

Sure, that seems sensible. It would require some changes in the architecture of how processors are currently handled, but not impossible.