Initial resolveDir is invalid when using Yarn Berry, paths in metafile.json are invalid too

[remorses]

When using yarn berry the initial resolveDir passed to plugins is invalid, for example /usr/morse/github/github becomes /usr/morse/github/github

The paths in metafile.json are invalid too, they have one more ../ than necessary, for example what should be ./index.ts becomes ../index.ts, this is probably because esbuild thinks cwd is /usr/morse/github/github instead of /usr/morse/github

This does not happen when using yarn 1, only with yarn berry

Reproduction:
https://github.com/remorses/esbuild-reproduction-wrong-resolveDir-in-yarn-berry

[remorses]

The problem is in the realpath function, it repeats the basename

esbuild/internal/fs/fs.go

Line 298 in c1d9d1a

func realpath(path string) string {

[evanw]

I did some investigation. This appears to be because in this specific case the path ends with /. When that happens filepath.Dir(path) ends with filepath.Base(path) instead of excluding it. I was unfortunately unable to construct an automated test of this scenario.