error-monitor-core

Core module for error monitoring SDK - A powerful, flexible error tracking solution for JavaScript applications.

Features

- 🎯 Error Capture: Automatically capture JavaScript errors, Promise rejections, and custom errors
- 🍞 Breadcrumbs: Track user actions and application events leading up to errors
- 🔌 Plugin System: Extensible architecture with lifecycle hooks
- 📊 Context Management: Rich context information including user data, tags, and custom metadata
- 🎛️ Sampling: Configurable sampling rates for optimal performance
- 🚫 Filtering: Filter out unwanted errors by pattern or URL
- 📦 Zero Dependencies: Lightweight core with minimal footprint

Installation

``bash
npm install error-monitor-core


or

pnpm install error-monitor-core

or

yarn add error-monitor-core
`

Quick Start

`typescript
import { ErrorMonitor } from 'error-monitor-core'

// Initialize the monitor
const monitor = new ErrorMonitor({
appId: 'your-app-id',
dsn: 'https://your-error-server.com/collect',
enabled: true
})

// Start monitoring
monitor.init()

// Capture errors manually
try {
// Your code
} catch (error) {
monitor.captureError(error)
}

// Capture custom messages
monitor.captureMessage('User clicked button', 'info', {
extra: { buttonId: 'submit' }
})

// Add breadcrumbs
monitor.addBreadcrumb({
type: 'navigation',
message: 'User navigated to /dashboard',
data: { from: '/home' }
})

// Set user information
monitor.setUser({
id: 'user-123',
username: 'john_doe',
email: 'john@example.com'
})

// Add tags
monitor.setTags({ environment: 'production', version: '1.0.0' })
`

Configuration

`typescript
interface Config {
// Basic
appId: string // Your application ID
dsn: string // Error collection server URL
environment?: string // Environment name (development, production, etc.)
release?: string // Release version
userId?: string // User ID
tags?: Record // Custom tags

// Sampling
sampleRate?: number // Overall sampling rate (0-1)
errorSampleRate?: number // Error-specific sampling rate (0-1)

// Auto-capture options
autoCapture?: {
js?: boolean // Auto-capture JavaScript errors
promise?: boolean // Auto-capture Promise rejections
network?: boolean // Auto-capture network errors
resource?: boolean // Auto-capture resource loading errors
console?: boolean // Auto-capture console errors
}

// Filtering
filter?: {
ignoreErrors?: RegExp[] // Error message patterns to ignore
ignoreUrls?: RegExp[] // URL patterns to ignore
minLevel?: LogLevel // Minimum error level to capture
}

// Reporting
report?: {
delay?: number // Batch reporting delay (ms)
batchSize?: number // Batch reporting size
customReporter?: (data: ErrorReport) => void | Promise
}

// Debug
debug?: boolean // Enable debug logging
enabled?: boolean // Enable/disable monitoring
}
`

API

$3

`typescript
new ErrorMonitor(config: Config)
`

$3

#### init(): void
Initialize the error monitor.

#### capture(error: ErrorType | Error, options?: CaptureOptions): void
Capture an error or custom message.

#### captureError(error: Error, options?: CaptureOptions): void
Convenience method for capturing Error objects.

#### captureMessage(message: string, level?: LogLevel, options?: CaptureOptions): void
Capture a custom message with optional level.

#### addBreadcrumb(crumb: Breadcrumb): void
Add a breadcrumb to the tracking timeline.

#### setUser(user: User): void
Set user information for all future error reports.

#### setTags(tags: Record): void
Set tags for all future error reports.

#### setSampleRate(rate: number): void
Set the overall sampling rate (0-1).

#### setErrorSampleRate(rate: number): void
Set the error-specific sampling rate (0-1).

#### addFilter(pattern: RegExp): void
Add an error filter pattern.

#### enable(): void
Enable error monitoring.

#### disable(): void
Disable error monitoring.

#### use(plugin: Plugin): void
Register a plugin.

#### destroy(): void
Cleanup and destroy the monitor instance.

Error Report Format

`typescript
interface ErrorReport {
appId: string
timestamp: number
sessionId: string
eventId: string

type: string
level: string
message: string
stack?: string

context: {
userAgent: string
url: string
viewport: { width: number; height: number }
userId?: string
tags?: Record
}

breadcrumbs: Breadcrumb[]
extra?: Record
}
`

Plugins

Create custom plugins to extend functionality:

`typescript
const myPlugin = {
name: 'my-plugin',

setup(core) {
// Called when plugin is registered
},

beforeCapture(error) {
// Modify error before capture
// Return null to skip capturing
return error
},

afterCapture(report) {
// Modify report after capture
return report
},

beforeReport(report) {
// Modify report before sending to server
return report
},

teardown() {
// Cleanup when monitor is destroyed
}
}

monitor.use(myPlugin)
``

License

MIT

Support

For issues and questions, please visit our GitHub repository.