frontend-plugin-api: add description and ID for ExternalRouteRef

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

packages/frontend-plugin-api/src/routing/ExternalRouteRef.test.ts

@@ -27,7 +27,12 @@ describe('ExternalRouteRef', () => {
     const internal = toInternalExternalRouteRef(routeRef);
     expect(internal.getParams()).toEqual([]);
     expect(internal.optional).toBe(false);
-    expect(String(internal)).toBe('routeRef{type=external,id=my-route-ref}');
+
+    expect(String(internal)).toMatch(
+      /^ExternalRouteRef\{created at '.*ExternalRouteRef\.test\.ts.*'\}$/,
+    );
+    internal.setId('some-id');
+    expect(String(internal)).toBe('ExternalRouteRef{some-id}');
   });
 
   it('should be created as optional', () => {

packages/frontend-plugin-api/src/routing/ExternalRouteRef.ts

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import { RouteRefImpl } from './RouteRef';
+import { describeParentCallSite } from './describeParentCallSite';
 import { AnyRouteParams } from './types';
 
 /**
@@ -41,6 +43,9 @@ export interface InternalExternalRouteRef<
 > extends ExternalRouteRef<TParams, TOptional> {
   readonly version: 'v1';
   getParams(): string[];
+  getDescription(): string;
+
+  setId(id: string): void;
 }
 
 /** @internal */
@@ -66,26 +71,18 @@ export function isExternalRouteRef(opaque: {
 }
 
 /** @internal */
-export class ExternalRouteRefImpl implements InternalExternalRouteRef {
-  readonly $$type = '@backstage/ExternalRouteRef';
-  readonly version = 'v1';
+class ExternalRouteRefImpl
+  extends RouteRefImpl
+  implements InternalExternalRouteRef
+{
+  readonly $$type = '@backstage/ExternalRouteRef' as any;
 
-  #params: string[];
-
-  constructor(readonly optional: boolean, readonly params: string[] = []) {
-    this.#params = params;
-  }
-
-  get T(): never {
-    throw new Error(`tried to read ExternalRouteRef.T of ${this}`);
-  }
-
-  getParams(): string[] {
-    return this.#params;
-  }
-
-  toString(): string {
-    return `ExternalRouteRef{}`;
+  constructor(
+    readonly optional: boolean,
+    readonly params: string[] = [],
+    creationSite: string,
+  ) {
+    super(params, creationSite);
   }
 }
 
@@ -129,5 +126,6 @@ export function createExternalRouteRef<
   return new ExternalRouteRefImpl(
     Boolean(options?.optional),
     options?.params as string[] | undefined,
+    describeParentCallSite(),
   ) as ExternalRouteRef<any, any>;
 }

packages/frontend-plugin-api/src/routing/RouteRef.ts

@@ -88,20 +88,24 @@ export class RouteRefImpl implements InternalRouteRef {
     return `created at '${this.#creationSite}'`;
   }
 
+  get #name() {
+    return this.$$type.slice('@backstage/'.length);
+  }
+
   setId(id: string): void {
     if (!id) {
-      throw new Error('RouteRef id must be a non-empty string');
+      throw new Error(`${this.#name} id must be a non-empty string`);
     }
     if (this.#id) {
       throw new Error(
-        `RouteRef was referenced twice as both '${this.#id}' and '${id}'`,
+        `${this.#name} was referenced twice as both '${this.#id}' and '${id}'`,
       );
     }
     this.#id = id;
   }
 
   toString(): string {
-    return `RouteRef{${this.getDescription()}}`;
+    return `${this.#name}{${this.getDescription()}}`;
   }
 }
 
@@ -126,9 +130,8 @@ export function createRouteRef<
     ? TParams
     : { [param in TParamKeys]: string }
 > {
-  const creationSite = describeParentCallSite();
   return new RouteRefImpl(
     config?.params as string[] | undefined,
-    creationSite,
+    describeParentCallSite(),
   ) as RouteRef<any>;
 }