error-handler-generator

Name: error-handler-generator
Author: girijashankarj

27stars3forks

How to install error-handler-generator?

girijashankarj/cursor-handbook/error-handler-generator

$npx -y skills add girijashankarj/cursor-handbook --skill error-handler-generator

Installs into the current project.

Summary

Generate typed error classes, error handling middleware, and HTTP error mapping following project conventions. Use when the user asks to set up error handling, create error classes, or implement error middleware.

Files · 1

View on GitHub

SKILL.md

1	# Skill: Error Handler Generator
2
3	Create a comprehensive error handling system with typed error classes, centralized middleware, and consistent API error responses.
4
5	## Trigger
6	When the user asks to create error handling, set up error classes, implement error middleware, or standardize error responses.
7
8	## Prerequisites
9	- [ ] Framework identified (Express, Fastify, Koa, etc.)
10	- [ ] Response envelope format known (`{ error: { code, message }, meta }`)
11	- [ ] Error categories for the domain identified
12
13	## Steps
14
15	### Step 1: Define Error Hierarchy
16
17	```typescript
18	// errors/base.ts
19	export class AppError extends Error {
20	public readonly statusCode: number;
21	public readonly code: string;
22	public readonly isOperational: boolean;
23	public readonly details?: Record<string, unknown>;
24
25	constructor(params: {
26	message: string;
27	statusCode: number;
28	code: string;
29	isOperational?: boolean;
30	details?: Record<string, unknown>;
31	}) {
32	super(params.message);
33	this.name = this.constructor.name;
34	this.statusCode = params.statusCode;
35	this.code = params.code;
36	this.isOperational = params.isOperational ?? true;
37	this.details = params.details;
38	Error.captureStackTrace(this, this.constructor);
39	}
40	}
41	```
42
43	### Step 2: Create Specific Error Classes
44
45	```typescript
46	// errors/index.ts
47	export class ValidationError extends AppError {
48	constructor(message: string, details?: Record<string, unknown>) {
49	super({ message, statusCode: 400, code: 'VALIDATION_ERROR', details });
50	}
51	}
52
53	export class AuthenticationError extends AppError {
54	constructor(message = 'Authentication required') {
55	super({ message, statusCode: 401, code: 'AUTHENTICATION_ERROR' });
56	}
57	}
58
59	export class AuthorizationError extends AppError {
60	constructor(message = 'Insufficient permissions') {
61	super({ message, statusCode: 403, code: 'AUTHORIZATION_ERROR' });
62	}
63	}
64
65	export class NotFoundError extends AppError {
66	constructor(resource: string, id?: string) {
67	const msg = id ? `${resource} with id '${id}' not found` : `${resource} not found`;
68	super({ message: msg, statusCode: 404, code: 'NOT_FOUND' });
69	}
70	}
71
72	export class ConflictError extends AppError {
73	constructor(message: string) {
74	super({ message, statusCode: 409, code: 'CONFLICT' });
75	}
76	}
77
78	export class RateLimitError extends AppError {
79	constructor(retryAfter?: number) {
80	super({
81	message: 'Rate limit exceeded',
82	statusCode: 429,
83	code: 'RATE_LIMIT_EXCEEDED',
84	details: retryAfter ? { retryAfterSeconds: retryAfter } : undefined,
85	});
86	}
87	}
88
89	export class ExternalServiceError extends AppError {
90	constructor(serviceName: string, message?: string) {
91	super({
92	message: message \|\| `External service error: ${serviceName}`,
93	statusCode: 502,
94	code: 'EXTERNAL_SERVICE_ERROR',
95	details: { service: serviceName },
96	});
97	}
98	}
99
100	export class InternalError extends AppError {
101	constructor(message = 'An unexpected error occurred') {
102	super({ message, statusCode: 500, code: 'INTERNAL_ERROR', isOperational: false });
103	}
104	}
105	```
106
107	### Step 3: Create Error Middleware
108
109	```typescript
110	// middleware/error-handler.ts
111	import { Request, Response, NextFunction } from 'express';
112	import { AppError } from '../errors/base';
113	import { logger } from '../utils/logger';
114
115	export function errorHandler(
116	err: Error,
117	req: Request,
118	res: Response,
119	_next: NextFunction
120	): void {
121	const correlationId = req.headers['x-correlation-id'] as string \|\| 'unknown';
122
123	if (err instanceof AppError) {
124	logger.warn({
125	correlationId,
126	error: err.code,
127	message: err.message,
128	statusCode: err.statusCode,
129	path: req.path,
130	method: req.method,
131	});
132
133	res.status(err.statusCode).json({
134	error: {
135	code: err.code,
136	message: err.message,
137	...(err.details && { details: err.details }),
138	},
139	meta: {
140	correlationId,
141	timestamp: new Date().toISOString(),
142	},
143	});
144	return;
145	}
146
147	// Unexpected errors — don't expose details
148	logger.error({
149	correlationId,
150	error: 'INTERNAL_ERROR',
151	message: err.message,
152	stack: err.stack,
153	path: req.path,
154	method: req.method,
155	});
156
157	res.status(500).json({
158	error: {
159	code: 'INTERNAL_ERROR',
160	message: 'An unexpected error occurred',
161	},
162	meta: {
163	correlationId,
164	timestamp: new Date().toISOString(),
165	},
166	});
167	}
168	```
169
170	### Step 4: Create Async Handler Wrapper
171
172	```typescript
173	// middleware/async-handler.ts
174	import { Request, Response, NextFunction, RequestHandler } from 'express';
175
176	export const asyncHandler = (
177	fn: (req: Request, res: Response, next: NextFunction) => Promise<void>
178	): RequestHandler => {
179	return (req, res, next) => {

People who liked this also viewed

6 picks

Type

error-handler-generator

27stars3forks

View on GitHub

How to install error-handler-generator?

girijashankarj/cursor-handbook/error-handler-generator

$npx -y skills add girijashankarj/cursor-handbook --skill error-handler-generator

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# Skill: Error Handler Generator
2
3	Create a comprehensive error handling system with typed error classes, centralized middleware, and consistent API error responses.
4
5	## Trigger
6	When the user asks to create error handling, set up error classes, implement error middleware, or standardize error responses.
7
8	## Prerequisites
9	- [ ] Framework identified (Express, Fastify, Koa, etc.)
10	- [ ] Response envelope format known (`{ error: { code, message }, meta }`)
11	- [ ] Error categories for the domain identified
12
13	## Steps
14
15	### Step 1: Define Error Hierarchy
16
17	```typescript
18	// errors/base.ts
19	export class AppError extends Error {
20	public readonly statusCode: number;
21	public readonly code: string;
22	public readonly isOperational: boolean;
23	public readonly details?: Record<string, unknown>;
24
25	constructor(params: {
26	message: string;
27	statusCode: number;
28	code: string;
29	isOperational?: boolean;
30	details?: Record<string, unknown>;
31	}) {
32	super(params.message);
33	this.name = this.constructor.name;
34	this.statusCode = params.statusCode;
35	this.code = params.code;
36	this.isOperational = params.isOperational ?? true;
37	this.details = params.details;
38	Error.captureStackTrace(this, this.constructor);
39	}
40	}
41	```
42
43	### Step 2: Create Specific Error Classes
44
45	```typescript
46	// errors/index.ts
47	export class ValidationError extends AppError {
48	constructor(message: string, details?: Record<string, unknown>) {
49	super({ message, statusCode: 400, code: 'VALIDATION_ERROR', details });
50	}
51	}
52
53	export class AuthenticationError extends AppError {
54	constructor(message = 'Authentication required') {
55	super({ message, statusCode: 401, code: 'AUTHENTICATION_ERROR' });
56	}
57	}
58
59	export class AuthorizationError extends AppError {
60	constructor(message = 'Insufficient permissions') {
61	super({ message, statusCode: 403, code: 'AUTHORIZATION_ERROR' });
62	}
63	}
64
65	export class NotFoundError extends AppError {
66	constructor(resource: string, id?: string) {
67	const msg = id ? `${resource} with id '${id}' not found` : `${resource} not found`;
68	super({ message: msg, statusCode: 404, code: 'NOT_FOUND' });
69	}
70	}
71
72	export class ConflictError extends AppError {
73	constructor(message: string) {
74	super({ message, statusCode: 409, code: 'CONFLICT' });
75	}
76	}
77
78	export class RateLimitError extends AppError {
79	constructor(retryAfter?: number) {
80	super({
81	message: 'Rate limit exceeded',
82	statusCode: 429,
83	code: 'RATE_LIMIT_EXCEEDED',
84	details: retryAfter ? { retryAfterSeconds: retryAfter } : undefined,
85	});
86	}
87	}
88
89	export class ExternalServiceError extends AppError {
90	constructor(serviceName: string, message?: string) {
91	super({
92	message: message \|\| `External service error: ${serviceName}`,
93	statusCode: 502,
94	code: 'EXTERNAL_SERVICE_ERROR',
95	details: { service: serviceName },
96	});
97	}
98	}
99
100	export class InternalError extends AppError {
101	constructor(message = 'An unexpected error occurred') {
102	super({ message, statusCode: 500, code: 'INTERNAL_ERROR', isOperational: false });
103	}
104	}
105	```
106
107	### Step 3: Create Error Middleware
108
109	```typescript
110	// middleware/error-handler.ts
111	import { Request, Response, NextFunction } from 'express';
112	import { AppError } from '../errors/base';
113	import { logger } from '../utils/logger';
114
115	export function errorHandler(
116	err: Error,
117	req: Request,
118	res: Response,
119	_next: NextFunction
120	): void {
121	const correlationId = req.headers['x-correlation-id'] as string \|\| 'unknown';
122
123	if (err instanceof AppError) {
124	logger.warn({
125	correlationId,
126	error: err.code,
127	message: err.message,
128	statusCode: err.statusCode,
129	path: req.path,
130	method: req.method,
131	});
132
133	res.status(err.statusCode).json({
134	error: {
135	code: err.code,
136	message: err.message,
137	...(err.details && { details: err.details }),
138	},
139	meta: {
140	correlationId,
141	timestamp: new Date().toISOString(),
142	},
143	});
144	return;
145	}
146
147	// Unexpected errors — don't expose details
148	logger.error({
149	correlationId,
150	error: 'INTERNAL_ERROR',
151	message: err.message,
152	stack: err.stack,
153	path: req.path,
154	method: req.method,
155	});
156
157	res.status(500).json({
158	error: {
159	code: 'INTERNAL_ERROR',
160	message: 'An unexpected error occurred',
161	},
162	meta: {
163	correlationId,
164	timestamp: new Date().toISOString(),
165	},
166	});
167	}
168	```
169
170	### Step 4: Create Async Handler Wrapper
171
172	```typescript
173	// middleware/async-handler.ts
174	import { Request, Response, NextFunction, RequestHandler } from 'express';
175
176	export const asyncHandler = (
177	fn: (req: Request, res: Response, next: NextFunction) => Promise<void>
178	): RequestHandler => {
179	return (req, res, next) => {

People who liked this also viewed

6 picks

Type