refactor: tidy structure of source files

Fixes #79

src/protocol/errors/plugin-already-registered.ts

@@ -0,0 +1,44 @@
+/*
+ * 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 {CONFLICT} from 'http-status-codes';
+import {SCError} from '../error';
+import {SCPluginMetaData} from '../routes/plugin-register';
+
+/**
+ * An error that is returned when a plugin with the same name is already registered, to prevent two copies of a plugin
+ * running at the same time.
+ * This usually indicates that there is more than one instance a plugin running.
+ */
+export class SCPluginAlreadyRegisteredErrorResponse extends SCError {
+  /**
+   * Meta data of a registered plugin, which is in a conflict with the plugin we want to register.
+   * If the stack is disabled this is not set for security reasons
+   */
+  additionalData?: SCPluginMetaData;
+
+  /**
+   * Create a SCPluginAlreadyRegisteredError
+   *
+   * @param message Provide further information why an already registered plugin matches the one we want to register
+   * @param plugin Provides meta data of a registered plugin, which is in a conflict with the plugin we want to register
+   * @param stack Set to true if a stack trace should be created
+   */
+  constructor(message: string, plugin: SCPluginMetaData, stack = false) {
+    super('SCPluginAlreadyRegisteredError', message, CONFLICT, stack);
+    if (stack) {
+      this.additionalData = plugin;
+    }
+  }
+}