core-api: add unused optional bindRoutes method to AppOptions

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

@@ -16,7 +16,8 @@
 
 import { ComponentType } from 'react';
 import { IconComponent, SystemIconKey, SystemIcons } from '../icons';
-import { BackstagePlugin } from '../plugin';
+import { BackstagePlugin, AnyExternalRoutes } from '../plugin';
+import { RouteRef } from '../routing';
 import { AnyApiFactory } from '../apis';
 import { AppTheme, ProfileInfo } from '../apis/definitions';
 import { AppConfig } from '@backstage/config';
@@ -78,6 +79,11 @@ export type AppComponents = {
  */
 export type AppConfigLoader = () => Promise<AppConfig[]>;
 
+type BindRouteFunc = <T extends AnyExternalRoutes>(
+  externalRoutes: T,
+  targetRoutes: { [key in keyof T]: RouteRef<any> },
+) => void;
+
 export type AppOptions = {
   /**
    * A collection of ApiFactories to register in the application to either
@@ -134,6 +140,26 @@ export type AppOptions = {
    *  that was packaged by the backstage-cli and default docker container boot script.
    */
   configLoader?: AppConfigLoader;
+
+  /**
+   * A function that is used to register associations between cross-plugin route
+   * references, enabling plugins to navigate between each other.
+   *
+   * The `bind` function that is passed in should be used to bind all external
+   * routes of all used plugins.
+   *
+   * ```ts
+   * bindRoutes({ bind }) {
+   *   bind(docsPlugin.externalRoutes, {
+   *     homePage: managePlugin.routes.managePage,
+   *   })
+   *   bind(homePagePlugin.externalRoutes, {
+   *     settingsPage: settingsPlugin.routes.settingsPage,
+   *   })
+   * }
+   * ```
+   */
+  bindRoutes?(context: { bind: BindRouteFunc }): void;
 };
 
 export type BackstageApp = {