Initial commit: Angular frontend and Expressjs backend

worklenz-backend/src/decorators/handle-exceptions.ts

@@ -0,0 +1,83 @@
+import WorklenzControllerBase from "../controllers/worklenz-controller-base";
+import {ServerResponse} from "../models/server-response";
+import {DEFAULT_ERROR_MESSAGE} from "../shared/constants";
+import {DB_CONSTRAINS} from "../shared/constraints";
+import {log_error} from "../shared/utils";
+import {Response} from "express";
+
+interface IExceptionHandlerConfig {
+  message?: string;
+  /** e.g. req.user? "user", req.body? "body" */
+  logWithError?: string;
+  /** Throws from postgres functions */
+  raisedExceptions?: { [x: string]: string };
+}
+
+const defaults: IExceptionHandlerConfig = {
+  message: DEFAULT_ERROR_MESSAGE,
+  raisedExceptions: {},
+  logWithError: "user"
+};
+
+const isValid = (options: any, key: string) => Object.keys(options[key] || {}).length > 0;
+const mergeWithDefaults = (options: any) => ({...defaults, ...(options || {})});
+
+function getConstraint(error: any) {
+  return DB_CONSTRAINS[error?.constraint] ?? null;
+}
+
+function getConstraintResponse(constraint: string) {
+  if (constraint === "[IGNORE]")
+    return new ServerResponse(true, null);
+  return new ServerResponse(false, null, constraint || DEFAULT_ERROR_MESSAGE);
+}
+
+function hasRaisedException(opt: any, keys: any[]): boolean {
+  return opt.raisedExceptions?.[keys[0]];
+}
+
+function getExceptionMessage(opt: any, keys: any[]) {
+  return (opt.raisedExceptions[keys[0]] || DEFAULT_ERROR_MESSAGE).replace(/(\{0\})/g, (keys[1] || ""));
+}
+
+function getKeys(error: any) {
+  return ((error?.message) || "").split(":");
+}
+
+function handleError(error: any, res: Response, opt: any, req: any) {
+  const constraint = getConstraint(error);
+  if (typeof constraint === "string") {
+    const response = getConstraintResponse(constraint);
+    return res.status(200).send(response);
+  }
+
+  if (isValid(opt, "raisedExceptions")) {
+    const keys = getKeys(error);
+    if (hasRaisedException(opt, keys)) {
+      const msg = getExceptionMessage(opt, keys);
+      return res.status(200).send(new ServerResponse(false, null, msg));
+    }
+  }
+
+  log_error(error, (opt.logWithError && req[opt.logWithError]) || null);
+  return res.status(200).send(new ServerResponse(false, null, opt.message));
+}
+
+/** HandleExceptions can only be used with an instance of WorklenzControllerBase. */
+export default function HandleExceptions(options?: IExceptionHandlerConfig) {
+  const opt = mergeWithDefaults(options);
+  return (target: any, key: string, descriptor: PropertyDescriptor) => {
+    if (!(target.prototype instanceof WorklenzControllerBase))
+      throw new Error("@HandleExceptions can only be used with an instance of WorklenzControllerBase.");
+
+    const originalMethod = descriptor.value;
+    descriptor.value = async (...args: any[]) => {
+      try {
+        return await originalMethod.apply(target, args);
+      } catch (error: any) {
+        const [req, res] = args;
+        return handleError(error, res, opt, req);
+      }
+    };
+  };
+}