[Go SDK] fileio.MatchAll() cannot match all files on GCS

[firehg]

The GCS filesystem's List() method in go/pkg/beam/io/filesystem/gcs/gcs.go uses filepath.Match(object, obj.Name) to filter listed objects. Since filepath.Match treats * as matching non-separator characters only (and / is the separator on Unix), patterns like gs://bucket/* and gs://bucket/** fail to match any GCS object whose name contains / — which is the vast majority of real-world GCS objects.
The Java and Python SDKs handle this correctly: Java's GcsUtil supports ** for recursive matching, and Python's fnmatch doesn't treat / as special.

Reproduction: fileio.MatchFiles(scope, "gs://my-bucket/*") returns only objects with no / in their name. Objects like dir/subdir/file.txt are silently excluded. Same for "gs://my-bucket/**"

Suggested fix: Replace filepath.Match with a matcher that doesn't treat / as a separator for cloud storage schemes, or add ** support similar to the Java SDK.

[hilaryRope]

Happy to pick this up, unless someone else has already "claimed it". I am a new contributor, so would like to help. Thanks

[hilaryRope]

.take-issue