Global Error Handling in JavaScript

1// Method 1: Window error handler
2window.addEventListener('error', function(event) {
3    console.error('Global error:', event.message);
4    console.error('File:', event.filename);
5    console.error('Line:', event.lineno);
6    console.error('Column:', event.colno);
7    console.error('Error:', event.error);
8    
9    // Send to error tracking service
10    // logErrorToService(event);
11    
12    // Prevent default browser error handling
13    // return true;
14});
15
16// Method 2: Unhandled promise rejection
17window.addEventListener('unhandledrejection', function(event) {
18    console.error('Unhandled promise rejection:', event.reason);
19    event.preventDefault(); // Prevent default handling
20});
21
22// Method 3: Node.js error handling
23if (typeof process !== 'undefined') {
24    process.on('uncaughtException', (error) => {
25        console.error('Uncaught exception:', error);
26        // Graceful shutdown
27        process.exit(1);
28    });
29    
30    process.on('unhandledRejection', (reason, promise) => {
31        console.error('Unhandled rejection:', reason);
32    });
33}
34
35// Method 4: Error boundary (React-like)
36class ErrorBoundary {
37    constructor() {
38        this.errors = [];
39    }
40    
41    catchError(error, errorInfo) {
42        this.errors.push({ error, errorInfo, timestamp: Date.now() });
43        console.error('Error caught:', error, errorInfo);
44    }
45    
46    getErrors() {
47        return this.errors;
48    }
49}
50
51const errorBoundary = new ErrorBoundary();
52
53// Method 5: Error logging service
54class ErrorLogger {
55    constructor() {
56        this.errors = [];
57    }
58    
59    log(error, context = {}) {
60        const errorEntry = {
61            message: error.message,
62            stack: error.stack,
63            context: context,
64            timestamp: new Date().toISOString(),
65            userAgent: navigator.userAgent,
66            url: window.location.href
67        };
68        
69        this.errors.push(errorEntry);
70        // Send to server
71        this.sendToServer(errorEntry);
72    }
73    
74    sendToServer(errorEntry) {
75        // fetch('/api/errors', { method: 'POST', body: JSON.stringify(errorEntry) });
76        console.log('Error logged:', errorEntry);
77    }
78}
79
80const errorLogger = new ErrorLogger();
81
82// Method 6: Error reporting
83function reportError(error, context) {
84    errorLogger.log(error, context);
85}
86
87// Wrap functions with error reporting
88function withErrorReporting(fn) {
89    return function(...args) {
90        try {
91            return fn.apply(this, args);
92        } catch (error) {
93            reportError(error, { function: fn.name, args });
94            throw error;
95        }
96    };
97}