server: add additional API v2 options to endpoints

* improve type definitions for v2 method
The method has to be lowercase because it is used as an index to get
the respective method of the router.

Co-authored-by: Johann150 <johann.galle@protonmail.com>

packages/backend/src/server/api/endpoints.ts

@@ -702,6 +702,24 @@ export interface IEndpointMeta {
 	 * 正常応答をキャッシュ (Cache-Control: public) する秒数
 	 */
 	readonly cacheSec?: number;
+
+	/**
+	 * API v2 options
+	 */
+	readonly v2?: {
+
+		/**
+		 * HTTP verb this endpoint supports
+		 */
+		readonly method: 'get' | 'put' | 'post' | 'patch' | 'delete';
+
+		/**
+		 * Path alias for v2 endpoint
+		 * 
+		 * @example (v0) /api/notes/create -> /api/v2/notes
+		 */
+		readonly alias?: string;
+	};
 }
 
 export interface IEndpoint {

packages/backend/src/server/api/index.ts

@@ -91,6 +91,11 @@ for (const endpoint of endpoints) {
 		} else {
 			router.get(`/${endpoint.name}`, async ctx => { ctx.status = 405; });
 		}
+
+		if (endpoint.meta.v2) {
+			const path = endpoint.meta.v2.alias ?? endpoint.name.replace(/-/g, '_');
+			router[endpoint.meta.v2.method](`/v2/${path}`, handler.bind(null, endpoint));
+		}
 	}
 }