If #195 is merged, the existing API will completely change and that will need a v3.0.0 release. We could use this release to add other (maybe) breaking changes.

I think of the following breaking changes:

• remove the defensive copy in JSZip#filter. Users already have access to zip.files, a defensive copy is pointless here.
• remove the deprecated API (see Deprecate internal functions exposed in the public API #123)
• add base64 support in async()
• change the createFolders default value from false to true. People are used to file managers creating folders, the false value is (only ?) needed when we don't generate a regular zip file (xlsx file for example)
• restrict content using JSZip.root in JSZip.generate (see JSZip.generate doesn't restrict content using JSZip.root #203)
• remove JSZip.compressions, it now requires internal objects to work
• make the type option in generateAsync() mandatory

Other non-breaking changes that could be nice to have:

• a JSZip#forEach method
• Blob input support (the user won't need anymore a FileReader)
• Promise input support

Do you have other ideas ? remarks ?