import { Query } from '@cucumber/gherkin-utils'
import * as messages from '@cucumber/messages'
import { Transform, TransformCallback } from 'stream'

export default class GherkinQueryStream extends Transform {
  constructor(private readonly gherkinQuery: Query) {
    super({ readableObjectMode: true, writableObjectMode: true })
  }

  _transform(
    envelope: messages.Envelope,
    encoding: string,
    callback: TransformCallback
  ): void {
    this.gherkinQuery.update(envelope)
    callback(null, envelope)
  }
}