Only the first vfile is processed

[remcohaszing]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)

Affected packages and versions

unified-engine@9.0.4

Link to runnable example

No response

Steps to reproduce

Run the following script:

#!/usr/bin/env node
import {unified} from 'unified'
import {engine} from 'unified-engine'
import {VFile} from 'vfile'

function plugin() {
  this.Parser = () => ({type: 'root'})
  this.Compiler = () => ''

  return (ast, file) => {
    file.message('Oh noez!')
  }
}

const files = [
  new VFile({path: new URL('file:///a.txt'), value: 'a'}),
  new VFile({path: new URL('file:///b.txt'), value: 'b'})
]

engine(
  {
    files,
    processor: unified().use(plugin)
  },
  (error, code, context) => {
    console.dir(context.files, {depth: 3})
  }
)

Expected behavior

For all given files the unified plugins are ran.

Actual behavior

Unified plugins are only run for the first vfile given.

If file paths are given as strings instead of vfiles, all given paths are processed.

If a combination of vfiles and string paths is given, all string paths are processed up to the first vfile.

Runtime

Node v16

Package manager

npm v6

OS

Linux

Build and bundle tools

Other (please specify in steps to reproduce)

[wooorm]

Running with debugging on probably provides more insight.
My hunch would be somewhere here: https://github.com/unifiedjs/unified-engine/blob/main/lib/file-pipeline/queue.js.

[wooorm]

released!