Refactor exception usage

src/function/sync/apply-actions/dispatch-helper/helper.ts

@@ -0,0 +1,54 @@
+/*
+ * server component for the TimeLimit App
+ * Copyright (C) 2019 - 2020 Jonas Lochmann
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, version 3 of the License.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import { ClientPushChangesRequestAction } from '../../../../api/schema'
+import { EventHandler } from '../../../../monitoring/eventhandler'
+import { ApplyActionException } from '../exception/index'
+import { EncodedActionSchemaMismatchException } from '../exception/invalidaction'
+import { parseEncodedAction } from '../parse-encoded-action'
+
+export async function dispatch<T1 extends { type: string }, T2> ({ type, action, validator, parser, applier, eventHandler }: {
+  type: 'app logic' | 'parent' | 'child'
+  action: ClientPushChangesRequestAction
+  validator: (input: any) => input is T1
+  parser: (input: T1) => T2
+  applier: (input: T2) => Promise<void>
+  eventHandler: EventHandler
+}) {
+  const parsedSerializedAction = parseEncodedAction(action)
+
+  if (!validator(parsedSerializedAction)) {
+    throw new EncodedActionSchemaMismatchException({ type, action: parsedSerializedAction })
+  }
+
+  const actionType = parsedSerializedAction.type
+
+  try {
+    const parsedAction = parser(parsedSerializedAction)
+
+    await applier(parsedAction)
+
+    eventHandler.countEvent('dispatched action:' + actionType)
+  } catch (ex) {
+    if (ex instanceof ApplyActionException) {
+      throw new ApplyActionException({
+        staticMessage: 'error during dispatching ' + actionType + ': ' + ex.staticMessage,
+        dynamicMessage: ex.dynamicMessage ? 'error during dispatching ' + actionType + ': ' + ex.dynamicMessage : undefined
+      })
+    } else throw ex
+  }
+}