@shurcooL I just got caught out using vfsgendev and I wonder whether you can help advise how best to fix this.

I forgot that post #787 a go generate is required after any changes to github.com/gopherjs/gopherjs/js. Indeed the CI build didn't give me any clues either; my test just failed for an innocuous reason.

After running go generate github.com/gopherjs/gopherjs/... I got a load of modification time changes in the two fs_vfsdata.go files in addition to the expected content change in js/js.go. Am I right in thinking this is because the modification times are taken from the files on disk?

What would seem ideal here would be that we run go generate github.com/gopherjs/gopherjs/... as one of the first steps in CI so that the subsequent diff -u <(echo -n) <(git status --porcelain) can help us catch when we've forgotten to regenerate anything. We are already running a generate step for the prelude for this exact reason.

But I think this requires some changes in vfsgendev or at least the way we are using it in GopherJS. The following repro is another way of demonstrating the issue:

cd `mktemp -d`
export GOPATH=$PWD
go get github.com/shurcooL/vfsgen/cmd/vfsgendev
go get github.com/gopherjs/gopherjs
cd src/github.com/gopherjs/gopherjs/
npm install
go generate ./...
git status --porcelain

gives the output:

 M compiler/gopherjspkg/fs_vfsdata.go
 M compiler/natives/fs_vfsdata.go

What do you think is the best way forward here?

Thanks