[DOC/BUG?] More concrete example of listing files in tar archive

[cherviakovtaskworld]

What / Why

I write nodejs scripts, one creates tar.gz archive, another one extracts it
Tooke me a while to get list of files from tar, I just want to await and get list

Example

I end up with following code, which looks weird but seems works
And I reading docs attentievly but couldn't get this way, until I see into code of node-tar

const listArchiveFiles = (archiveFileName) => {
  return new Promise((resolve, reject) => {
    let fileNames = []
    try {
      await tar.t({
        file: path.join(basePath, archiveFileName),
        cwd: basePath,
        onentry: (entry) => {
          // also for some reason typescript saying entry.path is a number, not a string
          fileNames.push(path.basename(entry.header.path))
        }
        resolve(fileNames)
      })
    }  catch (error) {
      reject(error)
    }
  })
}

Also, docs saying tar.t return event emitter, which is not true, either promise version or callback one returns undefined, callback provides only error argument. onentry triggered on files read, but according to docs there no end event, so there no way of knowing wether files still read or already finished. If I add sizes of each entry sum is less than whole archive size, of course.Initially I was hoping that there way to make tar.x to output list of files from the archive, but it is not working that way.

So I would like to ask to update docs with this example, update on what returned from tar.t and fix typescript.

[isaacs]

It returns a stream if you don't provide a file option, since it has to give you something to pipe into. In that case, yes, it does return an event emitter (technically, a stream).

We don't maintain the typescript definitions, and this library is not written in TypeScript, so you'll have to take that up with wherever those are coming from. Sounds like they're inaccurate. The entry.path has never been a number.

There is a bug in your code sample. You have resolve() in the options object, it should be one line lower.

const listArchiveFiles = (archiveFileName) => {
  return new Promise((resolve, reject) => {
    let fileNames = []
    try {
      await tar.t({
        file: path.join(basePath, archiveFileName),
        cwd: basePath,
        onentry: (entry) => {
          // also for some reason typescript saying entry.path is a number, not a string
          fileNames.push(path.basename(entry.header.path))
        }
        // you have it here--> resolve(fileNames)
      })
      resolve(fileNames) // <-- it should be here
    }  catch (error) {
      reject(error)
    }
  })
}

Here's a more simplified approach:

const listArchiveFiles = async (archiveFileName) => {
  const filenames = []
  await tar.t({
    file: path.join(basePath, archiveFileName),
    onentry: entry => fileNames.push(path.basename(entry.header.path)),
  })
  return filenames
}