core-api: add routes and externalRoutes to plugin interface

Co-authored-by: blam <ben@blam.sh>

packages/core-api/src/app/App.tsx

@@ -59,7 +59,7 @@ import { ApiResolver, ApiFactoryRegistry } from '../apis/system';
 type FullAppOptions = {
   apis: Iterable<AnyApiFactory>;
   icons: SystemIcons;
-  plugins: BackstagePlugin[];
+  plugins: BackstagePlugin<any, any>[];
   components: AppComponents;
   themes: AppTheme[];
   configLoader?: AppConfigLoader;
@@ -107,7 +107,7 @@ export class PrivateAppImpl implements BackstageApp {
 
   private readonly apis: Iterable<AnyApiFactory>;
   private readonly icons: SystemIcons;
-  private readonly plugins: BackstagePlugin[];
+  private readonly plugins: BackstagePlugin<any, any>[];
   private readonly components: AppComponents;
   private readonly themes: AppTheme[];
   private readonly configLoader?: AppConfigLoader;
@@ -125,7 +125,7 @@ export class PrivateAppImpl implements BackstageApp {
     this.defaultApis = options.defaultApis;
   }
 
-  getPlugins(): BackstagePlugin[] {
+  getPlugins(): BackstagePlugin<any, any>[] {
     return this.plugins;
   }
 

packages/core-api/src/app/types.ts

@@ -93,7 +93,7 @@ export type AppOptions = {
   /**
    * A list of all plugins to include in the app.
    */
-  plugins?: BackstagePlugin[];
+  plugins?: BackstagePlugin<any, any>[];
 
   /**
    * Supply components to the app to override the default ones.
@@ -140,7 +140,7 @@ export type BackstageApp = {
   /**
    * Returns all plugins registered for the app.
    */
-  getPlugins(): BackstagePlugin[];
+  getPlugins(): BackstagePlugin<any, any>[];
 
   /**
    * Get a common icon for this app.

packages/core-api/src/extensions/extensions.tsx

@@ -54,7 +54,7 @@ export function createReactExtension<Props extends {}>(options: {
 }): Extension<NamedExoticComponent<Props>> {
   const { component: Component, data = {} } = options;
   return {
-    expose(plugin: BackstagePlugin): NamedExoticComponent<Props> {
+    expose(plugin: BackstagePlugin<any, any>): NamedExoticComponent<Props> {
       const Result = (props: Props) => <Component {...props} />;
 
       attachComponentData(Result, 'core.plugin', plugin);

packages/core-api/src/plugin/Plugin.tsx

@@ -19,13 +19,18 @@ import {
   PluginOutput,
   BackstagePlugin,
   Extension,
+  AnyRoutes,
+  AnyExternalRoutes,
 } from './types';
 import { AnyApiFactory } from '../apis';
 
-export class PluginImpl implements BackstagePlugin {
+export class PluginImpl<
+  Routes extends AnyRoutes,
+  ExternalRoutes extends AnyExternalRoutes
+> implements BackstagePlugin<Routes, ExternalRoutes> {
   private storedOutput?: PluginOutput[];
 
-  constructor(private readonly config: PluginConfig) {}
+  constructor(private readonly config: PluginConfig<Routes, ExternalRoutes>) {}
 
   getId(): string {
     return this.config.id;
@@ -35,6 +40,14 @@ export class PluginImpl implements BackstagePlugin {
     return this.config.apis ?? [];
   }
 
+  get routes(): Routes {
+    return this.config.routes ?? ({} as Routes);
+  }
+
+  get externalRoutes(): ExternalRoutes {
+    return this.config.externalRoutes ?? ({} as ExternalRoutes);
+  }
+
   output(): PluginOutput[] {
     if (this.storedOutput) {
       return this.storedOutput;
@@ -79,6 +92,11 @@ export class PluginImpl implements BackstagePlugin {
   }
 }
 
-export function createPlugin(config: PluginConfig): BackstagePlugin {
+export function createPlugin<
+  Routes extends AnyRoutes,
+  ExternalRoutes extends AnyExternalRoutes
+>(
+  config: PluginConfig<Routes, ExternalRoutes>,
+): BackstagePlugin<Routes, ExternalRoutes> {
   return new PluginImpl(config);
 }

packages/core-api/src/plugin/collectors.ts

@@ -34,9 +34,12 @@ import { getComponentData } from '../extensions';
 import { createCollector } from '../extensions/traversal';
 
 export const pluginCollector = createCollector(
-  () => new Set<BackstagePlugin>(),
+  () => new Set<BackstagePlugin<any, any>>(),
   (acc, node) => {
-    const plugin = getComponentData<BackstagePlugin>(node, 'core.plugin');
+    const plugin = getComponentData<BackstagePlugin<any, any>>(
+      node,
+      'core.plugin',
+    );
     if (plugin) {
       acc.add(plugin);
     }

packages/core-api/src/plugin/types.ts

@@ -17,6 +17,7 @@
 import { ComponentType } from 'react';
 import { RouteRef } from '../routing';
 import { AnyApiFactory } from '../apis/system';
+import { ExternalRouteRef } from '../routing/RouteRef';
 
 export type RouteOptions = {
   // Whether the route path must match exactly, defaults to true.
@@ -67,20 +68,34 @@ export type PluginOutput =
   | FeatureFlagOutput;
 
 export type Extension<T> = {
-  expose(plugin: BackstagePlugin): T;
+  expose(plugin: BackstagePlugin<any, any>): T;
 };
 
-export type BackstagePlugin = {
+export type AnyRoutes = { [name: string]: RouteRef<any> };
+
+export type AnyExternalRoutes = { [name: string]: ExternalRouteRef };
+
+export type BackstagePlugin<
+  Routes extends AnyRoutes,
+  ExternalRoutes extends AnyExternalRoutes
+> = {
   getId(): string;
   output(): PluginOutput[];
   getApis(): Iterable<AnyApiFactory>;
   provide<T>(extension: Extension<T>): T;
+  routes: Routes;
+  externalRoutes: ExternalRoutes;
 };
 
-export type PluginConfig = {
+export type PluginConfig<
+  Routes extends AnyRoutes,
+  ExternalRoutes extends AnyExternalRoutes
+> = {
   id: string;
   apis?: Iterable<AnyApiFactory>;
   register?(hooks: PluginHooks): void;
+  routes?: Routes;
+  externalRoutes?: ExternalRoutes;
 };
 
 export type PluginHooks = {