feat(librarian): allow APIs to have no service config (#1854)

jskeet · web-flow · commit f88a51a7e40d · 2025-08-28T08:45:56.000-04:00
This allows libraries from "just protos" to be represented. Fixes #1712.
diff --git a/internal/librarian/state.go b/internal/librarian/state.go
@@ -146,7 +146,8 @@ func findServiceConfigIn(path string) (string, error) {
 		}
 	}
 
-	return "", errors.New("could not find service config in " + path)
+	// No service config present: assume it's proto-only.
+	return "", nil
 }
 
 func saveLibrarianState(repoDir string, state *config.LibrarianState) error {
diff --git a/internal/librarian/state_test.go b/internal/librarian/state_test.go
@@ -121,22 +121,16 @@ func TestFindServiceConfigIn(t *testing.T) {
 			want: "service_config.yaml",
 		},
 		{
-			name:    "non existed source path",
-			path:    filepath.Join("..", "..", "testdata", "non-existed-path"),
+			name:    "non-existent source path",
+			path:    filepath.Join("..", "..", "testdata", "non-existent-path"),
 			want:    "",
 			wantErr: true,
 		},
 		{
-			name:    "non service config in a source path",
+			name:    "no service config in a source path",
 			path:    filepath.Join("..", "..", "testdata", "no_service_config"),
 			want:    "",
-			wantErr: true,
-		},
-		{
-			name:    "simulated load error",
-			path:    filepath.Join("..", "..", "testdata", "no_service_config"),
-			want:    "",
-			wantErr: true,
+			wantErr: false,
 		},
 		{
 			name:    "invalid yaml",

Original file line number	Diff line number	Diff line change
`@@ -146,7 +146,8 @@ func findServiceConfigIn(path string) (string, error) {`
`146`	`146`	`}`
`147`	`147`	`}`
`148`	`148`
`149`		`- return "", errors.New("could not find service config in " + path)`
	`149`	`+ // No service config present: assume it's proto-only.`
	`150`	`+ return "", nil`
`150`	`151`	`}`
`151`	`152`
`152`	`153`	`func saveLibrarianState(repoDir string, state *config.LibrarianState) error {`