Asset uploadIfChanged only runs for files not for directories

[brad-jones]

When using new AssetCode('/some/path'), a zip file is created using prepareZipAsset and then uploaded using prepareFileAsset which executes uploadIfChanged.

The problem is that the zip file obviously has some timestamp data (or similar) in it that changes the hash of the file. So on every single deployment, regardless of if the asset has actually changed or not, a new asset is uploaded.

prepareZipAsset should either produce a idempot zip file or it should run a similar zipIfChanged function.

Anyway my workaround for now has been to use https://github.com/aws/aws-lambda-go/blob/master/cmd/build-lambda-zip/main.go to generate the zip of my lambdas and then get CDK to just upload the zip.

FYI: build-lambda-zip does produce an idempot zip file.

[spg]

It seems like it's linked to the order of the files in the zip file (not the timestamps of the files themselves) #2759