fix: nested `zipDirectory` filename causes zipping corrupted zip

[alestiago]

Description

When using zipDirectory and specifying the filename as a path within the directory, the resulting zipped file will have a corrupted zip inside.

Minimal reproductive sample code

Repository with sample code

import 'dart:io';
import 'package:archive/archive_io.dart';
import 'package:path/path.dart' as path;

void main() {
  final inputDirectory = Directory(
    path.join(Directory.current.path, 'input_zip'),
  )..createSync(recursive: true);
  final outputDirectory = Directory(
    path.join(Directory.current.path, 'output_zip'),
  )..createSync(recursive: true);

  File(path.join(inputDirectory.path, 'file1.txt')).writeAsStringSync('file1');

  const zipFileName = 'output1.zip';
  final zipFilePath = path.join(inputDirectory.path, zipFileName);
  ZipFileEncoder().zipDirectory(inputDirectory, filename: zipFilePath);

  final zipBytes = File(
    zipFilePath,
  ).readAsBytesSync();

  File(
    path.join(outputDirectory.path, 'output2.zip'),
  )
    ..createSync(recursive: true)
    ..writeAsBytesSync(zipBytes);
}

Run the above snippet of code locally and unzip the output's directory zip file. It will have the text file and a corrupted zip.

Proposals

• Show warning when filename's path is nested within directory.path
• Avoiding filename being a path and only extract the filename from the filename path
• Gracefully detect and resolve this scenarios

Additional context

• I'm willing to work on a solution if we agree this is an issue and settle on how this should be resolved.

[brendan-duncan]

I'm trying to figure out what you're doing here, but yes there does seem to be a problem. You're zipping a directory, and the path of the zip file being created is inside the directory you're zipping.

My thought is it should throw an exception in this case.

[alestiago]

My thought is it should throw an exception in this case.

I'm happy with this approach! Would you like me to contribute or do you prefer taking care of this?

[brendan-duncan]

I'd be glad if you could take care of it, thanks!

[alestiago]

Fantastic! Feel free to assign this to me, I will look into making a Pull Request between this week and next week.