improve error handling in background jobs #3

api/src/errors/background-error.ts

@@ -0,0 +1,49 @@
+// Error classes for background jobs
+
+// Class for custom background errors
+export class BackgroundJobError extends Error{
+    cause?: unknown;
+
+    constructor(message: string, cause?: unknown){
+        super(message);
+        this.name = this.constructor.name;
+        this.cause = cause;
+    }
+}
+
+// Errors based on class BackgroundJobError
+export class BackgroundDatabaseError extends BackgroundJobError{
+    constructor(cause?: unknown){
+        super('Database request failed.', cause);
+    }
+}
+
+export class BackgroundFetchError extends BackgroundJobError{
+    constructor(cause?: unknown){
+        super('Fetching data failed', cause);
+    }
+}
+
+export class AttractionImportError extends BackgroundJobError{
+    constructor(cause?: unknown){
+        super('Failed to import attractions into database.', cause);
+    }
+}
+
+export class ThemeparkUpdateError extends BackgroundJobError{
+    constructor(cause?: unknown){
+        super('Failed to update themepark data.', cause);
+    }
+}
+
+export class KVParseError extends BackgroundJobError{
+    constructor(key: string, cause?: unknown){
+        super(`Failed to parse JSON from KV, affected key: ${key}`, cause);
+    }
+}
+
+export class SendNotificationError extends BackgroundJobError{
+    constructor(cause?: unknown){
+        super('Failed to send notification.', cause);
+    }
+}

api/src/jobs/send-notifications.ts

@@ -3,6 +3,7 @@ import { getDbEnv } from '../db/client'
 import { subscribedThemeparks, attractionSubscriptions } from "../db/schema";
 import { SubscribedThemeparks } from "../types/subscribed-themeparks";
 import { AttractionSubscription } from "../types/attraction-subscriptions";
+import { KVParseError, SendNotificationError } from "../errors/background-error";
 import httpRequest from "../lib/http-request";
 import fetchAttractions from "../lib/fetch-attractions";
 
@@ -11,6 +12,7 @@ import fetchAttractions from "../lib/fetch-attractions";
  * waittime in cache & send notification about changes in waittime.
  * @param env Connection to Cloudflare
  */
+// TODO: split into batches by cron, when more than 10 parks have to be fetched -> like update-attraction-list.ts
 export default async function updateWaittimes(env: Env): Promise<void>{
     const db = getDbEnv(env);
     const subscribedParks = await db.select().from(subscribedThemeparks);
@@ -54,7 +56,7 @@ async function getJsonFromKV<T>(env: Env, key: string, defaultValue: T): Promise
         return JSON.parse(cache) as T;
     }
     catch(e){
-        throw new Error(`Failed to parse JSON from KV, affected key: ${key}, error: ${e}`);
+        throw new KVParseError(key, e);
     }
 }
 
@@ -131,7 +133,7 @@ async function sendNotification(webhookUrl: string, message: string, type: strin
         });
     }
     catch(e){
-        throw new Error(`Failed to send notification: ${e}`);
+        throw new SendNotificationError(e);
     }
 }
 

api/src/jobs/update-attraction-list.ts

@@ -3,6 +3,7 @@ import { attraction, themepark } from '../db/schema'
 import { inArray } from 'drizzle-orm'
 import { Attraction } from '../types/attraction'
 import { ThemeparkSelect } from '../types/themepark'
+import { AttractionImportError, BackgroundDatabaseError } from '../errors/background-error'
 import asyncBatchJob from '../lib/async-batch-job'
 import fetchAttractions from '../lib/fetch-attractions'
 
@@ -24,7 +25,7 @@ async function getThemeparks(env: Env): Promise<ThemeparkAPI[]>{
         return themeparks;
     }
     catch(e){
-        throw new Error(`Failed to get themeparks from database: ${e}`);
+        throw new BackgroundDatabaseError(e);
     }
 }
 
@@ -50,7 +51,7 @@ async function getAttractionsByParks(env: Env, parks: ThemeparkAPI[]): Promise<A
         return attractions;
     }
     catch(e){
-        throw new Error(`Failed to get attractions from database: ${e}`);
+        throw new BackgroundDatabaseError(e);
     }
 }
 
@@ -86,7 +87,7 @@ async function importAttractionsByParks(env: Env, parks: ThemeparkAPI[]): Promis
         }
     }
     catch(e){
-        throw new Error(`Failed to import attractions into database: ${e}`);
+        throw new AttractionImportError(e);
     }
 }
 
@@ -99,7 +100,6 @@ async function importAttractionsByParks(env: Env, parks: ThemeparkAPI[]): Promis
  * @param cron The cron statement specified to run the background jobs; used for batch size calculation
  */
 export async function batchAttractionImport(env: Env, timestamp: number, cron: string): Promise<void>{
-    try{
     const themeparks = await getThemeparks(env); // all themeparks
     const executionHour = new Date(timestamp).getUTCHours(); // current hour, in which job is executed
     const executionTimes = getExecutionCountFromCron(cron, 1); // how often the job is executed
@@ -117,10 +117,6 @@ export async function batchAttractionImport(env: Env, timestamp: number, cron: s
     // import attractions from current time batch
     await importAttractionsByParks(env, batch);
 }
-    catch(e){
-        throw new Error(`Failed to split attraction import by time: ${e}`);
-    }
-}
 
 /**
  * Calculates how often cron job gets executed

api/src/jobs/update-themepark-data.ts

@@ -1,6 +1,7 @@
 import { getDbEnv } from '../db/client'
 import { themepark } from '../db/schema'
 import { countryCodesDE } from '../lib/countries'
+import { BackgroundFetchError, ThemeparkUpdateError } from '../errors/background-error'
 import httpRequest from '../lib/http-request'
 import asyncBatchJob from '../lib/async-batch-job'
 
@@ -30,7 +31,7 @@ async function fetchThemeparks(
         return result;
     }
     catch(e){
-        throw new Error(`Fetching themeparks failed: ${e}`);
+        throw new BackgroundFetchError(e);
     }
 }
 
@@ -67,6 +68,6 @@ export async function updateThemeparkData(env: Env): Promise<void>{
         }
     }
     catch(e){
-        console.error(`Failed to update themepark data: ${e}`);
+        throw new ThemeparkUpdateError(e);
     }
 }

api/src/lib/user-auth.ts

@@ -4,7 +4,7 @@ import { UserSelect } from "../types/user";
 import { user } from "../db/schema";
 import { like } from "drizzle-orm";
 import { DrizzleD1Database } from "drizzle-orm/d1";
-import { MissingMailError, UserInactiveError, DatabaseError } from "../types/error";
+import { MissingMailError, UserInactiveError, DatabaseError } from "../errors/http-error";
 
 /**
  * Returns the details of a user from the given context

api/src/routes/attraction.ts

@@ -2,7 +2,7 @@ import { Hono, Context } from 'hono'
 import { getDbContext } from '../db/client'
 import { attractionNotification, notificationMethod } from '../db/schema'
 import { and, eq } from 'drizzle-orm'
-import { DatabaseError, InvalidParameter, MissingParameter } from '../types/error'
+import { DatabaseError, InvalidParameter, MissingParameter } from '../errors/http-error'
 import { getUser } from '../lib/user-auth'
 import { Message } from '../types/response'
 import { NotificationMethodSelect } from '../types/notification-method'

api/src/routes/themepark.ts

@@ -3,7 +3,7 @@ import { getDbContext } from '../db/client'
 import { themepark, attraction } from '../db/schema'
 import { responseCache } from '../lib/cache'
 import { eq } from 'drizzle-orm'
-import { DatabaseError } from '../types/error'
+import { DatabaseError } from '../errors/http-error'
 
 const app = new Hono()