feat: add plugin class

Fixes #12

test/TestPlugin.ts

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2019 StApps
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import * as express from 'express';
+import {Plugin} from '../src/plugin';
+
+/**
+ * A test plugin we use for all the tests
+ *
+ * It can be constructed without any parameter at all, or with all parameters if we want to test it
+ * It also serves as kind of a minimal plugin
+ */
+export class TestPlugin extends Plugin {
+  protected async onRouteInvoke(_req: express.Request, res: express.Response): Promise<void> {
+    res.json({});
+    return undefined;
+  }
+}