fix(internal/librarian/nodejs): stop renaming snippet metadata files (#4840)

The copySamplesFromStaging function was renaming snippet metadata files
from the generator's underscore pattern (snippet_metadata_<api>.json) to
a dot pattern (snippet_metadata.<api>.json). This caused repos to end up
with both naming variants, since the old dot-pattern files were never
cleaned up.

Use the generator's underscore pattern as the canonical name.

Author: julieqiu

internal/librarian/nodejs/generate.go

@@ -450,13 +450,6 @@ func copySamplesFromStaging(stagingDir, outDir string) error {
 			if err != nil {
 				return err
 			}
-			// The generator produces snippet_metadata_<api>.json but the
-			// existing convention uses snippet_metadata.<api>.json.
-			base := filepath.Base(rel)
-			if strings.HasPrefix(base, "snippet_metadata_") {
-				renamed := "snippet_metadata." + strings.TrimPrefix(base, "snippet_metadata_")
-				rel = filepath.Join(filepath.Dir(rel), renamed)
-			}
 			dst := filepath.Join(outDir, "samples", rel)
 			if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
 				return err

internal/librarian/nodejs/generate_test.go

@@ -824,13 +824,13 @@ func TestCopySamplesFromStaging(t *testing.T) {
 			want: "console.log('v1');",
 		},
 		{
-			name: "v1 renamed metadata",
-			path: filepath.Join(outDir, "samples", "generated", "v1", "snippet_metadata.google.cloud.test.v1.json"),
+			name: "v1 metadata",
+			path: filepath.Join(outDir, "samples", "generated", "v1", "snippet_metadata_google.cloud.test.v1.json"),
 			want: `{"snippets":[]}`,
 		},
 		{
-			name: "v1beta1 renamed metadata",
-			path: filepath.Join(outDir, "samples", "generated", "v1beta1", "snippet_metadata.google.cloud.test.v1beta1.json"),
+			name: "v1beta1 metadata",
+			path: filepath.Join(outDir, "samples", "generated", "v1beta1", "snippet_metadata_google.cloud.test.v1beta1.json"),
 			want: `{"snippets":["beta"]}`,
 		},
 	} {
@@ -844,12 +844,6 @@ func TestCopySamplesFromStaging(t *testing.T) {
 			}
 		})
 	}
-
-	// Verify the old underscore-prefixed names do not exist.
-	oldV1 := filepath.Join(outDir, "samples", "generated", "v1", "snippet_metadata_google.cloud.test.v1.json")
-	if _, err := os.Stat(oldV1); !errors.Is(err, os.ErrNotExist) {
-		t.Error("expected snippet_metadata_ file to be renamed, but old name still exists")
-	}
 }
 
 func TestCopySamplesFromStaging_NonExistentDir(t *testing.T) {