How to create ZIP files including the trailing descriptor signatures

[simonbuchan]

As described in APPNOTE.TXT:

4.3.9.3 Although not originally assigned a signature, the value
0x08074b50 has commonly been adopted as a signature value
for the data descriptor record. Implementers SHOULD be
aware that ZIP files MAY be encountered with or without this
signature marking data descriptors and SHOULD account for
either case when reading ZIP files to ensure compatibility.

In other words, the local entry for such files looks like:

[header...] [data...] "PK\7\8" crc32  compressed_size uncompressed_size

The AWS CloudFormation resource schema is (currently?) an example of such a file: https://schema.cloudformation.us-east-1.amazonaws.com/CloudformationSchema.zip

[gildas-lormeau]

You have to set the option dataDescriptorSignature to true, see https://gildas-lormeau.github.io/zip.js/api/interfaces/ZipWriterConstructorOptions.html#dataDescriptorSignature.

[simonbuchan]

Gah. This totally does work, sorry for the confusion - I somehow managed to get an error earlier, but I can't figure out what I was doing wrong now.

[gildas-lormeau]

No problem, it was actually set to true by default in the past but macOS did not support it.

[simonbuchan]

(to be clear, I was meaning to read such files, but this is handy anyway!)