feat: parse non-standard metadata filenames

tile-generator creates metadata filenames that are not "metadata/metadata.yml"
with this change you can parse those tiles with the tile.ReadMetadata* functions

fixes: #403

pkg/tile/metadata.go

@@ -30,7 +30,15 @@ func ReadMetadataFromZip(ra io.ReaderAt, zipFileSize int64) ([]byte, error) {
 }
 
 func ReadMetadataFromFS(dir fs.FS) ([]byte, error) {
- metadataFile, err := dir.Open("metadata/metadata.yml")
+ const pattern = "metadata/*.yml"
+ matches, err := fs.Glob(dir, pattern)
+ if err != nil {
+ return nil, err
+ }
+ if len(matches) == 0 {
+ return nil, fmt.Errorf("metadata file not found in the tile: expected a file matching glob %q", pattern)
+ }
+ metadataFile, err := dir.Open(matches[0])
  if err != nil {
  return nil, fmt.Errorf("failed to do open metadata zip file: %w", err)
  }

pkg/tile/metadata_test.go

@@ -2,6 +2,7 @@ package tile_test
 
 import (
  "testing"
+ "testing/fstest"
 
  . "github.com/onsi/gomega"
  "gopkg.in/yaml.v2"
@@ -23,3 +24,13 @@ func TestReadMetadataFromFile(t *testing.T) {
 
  please.Expect(metadata.Name).To(Equal("hello"), string(metadataBytes))
 }
+
+func TestNonStandardMetadataFilename(t *testing.T) {
+ fileFS := fstest.MapFS{
+ "metadata/banana.yml": &fstest.MapFile{Data: []byte(`{name: "banana"}`)},
+ }
+ buf, err := tile.ReadMetadataFromFS(fileFS)
+ please := NewWithT(t)
+ please.Expect(err).NotTo(HaveOccurred())
+ please.Expect(string(buf)).To(Equal(`{name: "banana"}`))
+}