frontend-plugin-api: add OverridableFrontendPlugin type

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

packages/frontend-plugin-api/src/wiring/createFrontendPlugin.ts

@@ -88,8 +88,12 @@ export type FrontendPluginInfoOptions = {
   manifest?: () => Promise<JsonObject>;
 };
 
-/** @public */
-export interface FrontendPlugin<
+/**
+ * A variant of the {@link FrontendPlugin} interface that can also be used to install overrides for the plugin.
+ *
+ * @public
+ */
+export interface OverridableFrontendPlugin<
   TRoutes extends { [name in string]: RouteRef | SubRouteRef } = {
     [name in string]: RouteRef | SubRouteRef;
   },
@@ -99,6 +103,26 @@ export interface FrontendPlugin<
   TExtensionMap extends { [id in string]: ExtensionDefinition } = {
     [id in string]: ExtensionDefinition;
   },
+> extends FrontendPlugin<TRoutes, TExternalRoutes> {
+  getExtension<TId extends keyof TExtensionMap>(id: TId): TExtensionMap[TId];
+  withOverrides(options: {
+    extensions: Array<ExtensionDefinition>;
+
+    /**
+     * Overrides the original info loaders of the plugin one by one.
+     */
+    info?: FrontendPluginInfoOptions;
+  }): OverridableFrontendPlugin<TRoutes, TExternalRoutes, TExtensionMap>;
+}
+
+/** @public */
+export interface FrontendPlugin<
+  TRoutes extends { [name in string]: RouteRef | SubRouteRef } = {
+    [name in string]: RouteRef | SubRouteRef;
+  },
+  TExternalRoutes extends { [name in string]: ExternalRouteRef } = {
+    [name in string]: ExternalRouteRef;
+  },
 > {
   readonly $$type: '@backstage/FrontendPlugin';
   readonly id: string;
@@ -109,15 +133,6 @@ export interface FrontendPlugin<
    * Loads the plugin info.
    */
   info(): Promise<FrontendPluginInfo>;
-  getExtension<TId extends keyof TExtensionMap>(id: TId): TExtensionMap[TId];
-  withOverrides(options: {
-    extensions: Array<ExtensionDefinition>;
-
-    /**
-     * Overrides the original info loaders of the plugin one by one.
-     */
-    info?: FrontendPluginInfoOptions;
-  }): FrontendPlugin<TRoutes, TExternalRoutes, TExtensionMap>;
 }
 
 /** @public */
@@ -172,7 +187,7 @@ export function createFrontendPlugin<
   TExtensions extends readonly ExtensionDefinition[] = [],
 >(
   options: PluginOptions<TId, TRoutes, TExternalRoutes, TExtensions>,
-): FrontendPlugin<
+): OverridableFrontendPlugin<
   TRoutes,
   TExternalRoutes,
   MakeSortedExtensionsMap<TExtensions[number], TId>

packages/frontend-plugin-api/src/wiring/index.ts

@@ -39,6 +39,7 @@ export {
 export {
   createFrontendPlugin,
   type FrontendPlugin,
+  type OverridableFrontendPlugin,
   type PluginOptions,
   type FrontendPluginInfo,
   type FrontendPluginInfoOptions,