frontend-plugin-api: refactor to use opaque type for route refs

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/frontend-internal/src/index.ts

@@ -14,4 +14,5 @@
  * limitations under the License.
  */
 
+export * from './routing';
 export * from './wiring';

packages/frontend-internal/src/routing/OpaqueExternalRouteRef.ts

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2025 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { ExternalRouteRef } from '@backstage/frontend-plugin-api';
+import { OpaqueType } from '@internal/opaque';
+
+export const OpaqueExternalRouteRef = OpaqueType.create<{
+  public: ExternalRouteRef;
+  versions: {
+    readonly version: 'v1';
+
+    getParams(): string[];
+    getDescription(): string;
+    getDefaultTarget(): string | undefined;
+
+    setId(id: string): void;
+  };
+}>({
+  type: '@backstage/ExternalRouteRef',
+  versions: ['v1'],
+});

packages/frontend-internal/src/routing/OpaqueRouteRef.ts

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2025 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { RouteRef } from '@backstage/frontend-plugin-api';
+import { OpaqueType } from '@internal/opaque';
+
+export const OpaqueRouteRef = OpaqueType.create<{
+  public: RouteRef;
+  versions: {
+    readonly version: 'v1';
+
+    getParams(): string[];
+    getDescription(): string;
+
+    alias: string | undefined;
+
+    setId(id: string): void;
+  };
+}>({
+  type: '@backstage/RouteRef',
+  versions: ['v1'],
+});

packages/frontend-internal/src/routing/OpaqueSubRouteRef.ts

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2025 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { RouteRef, SubRouteRef } from '@backstage/frontend-plugin-api';
+import { OpaqueType } from '@internal/opaque';
+
+export const OpaqueSubRouteRef = OpaqueType.create<{
+  public: SubRouteRef;
+  versions: {
+    readonly version: 'v1';
+
+    getParams(): string[];
+    getParent(): RouteRef;
+    getDescription(): string;
+  };
+}>({
+  type: '@backstage/SubRouteRef',
+  versions: ['v1'],
+});

packages/frontend-internal/src/routing/index.ts

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2025 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export { OpaqueRouteRef } from './OpaqueRouteRef';
+export { OpaqueSubRouteRef } from './OpaqueSubRouteRef';
+export { OpaqueExternalRouteRef } from './OpaqueExternalRouteRef';