Extending MSR

Extend and customize Migration Script Runner to fit your needs.

Overview

MSR is designed to be highly customizable. This section covers how to extend the framework with your own implementations for logging, rendering, validation, and lifecycle hooks.

Customization Areas

📝 Loggers

Built-in and custom logger implementations:

  • ConsoleLogger - Standard console output
  • SilentLogger - No output (testing)
  • FileLogger - Log to files
  • Cloud Logger - Cloud logging services
  • CompositeLogger - Multiple destinations
  • Custom Loggers - Implement your own

🎨 Render Strategies

Output format implementations:

  • AsciiTableRenderStrategy - Beautiful terminal tables
  • JsonRenderStrategy - Structured JSON output
  • SilentRenderStrategy - No output
  • Custom Renderers - Create custom formats

🔧 Custom Logging

Implement custom logger behavior:

  • Logger interface implementation
  • Integration with logging frameworks
  • Multi-destination logging
  • Log levels and formatting

🖼️ Custom Rendering

Create custom output formats:

  • Render strategy interface
  • Custom table formats
  • JSON variations
  • Integration with reporting tools

🪝 Migration Hooks

Extend migration lifecycle:

  • beforeMigrate and afterMigrate hooks
  • Notifications and alerts
  • Custom validation
  • Integration with external systems

📊 Metrics Collection

Track and monitor migration performance:

  • ConsoleMetricsCollector - Development feedback
  • LoggerMetricsCollector - Production monitoring
  • JsonMetricsCollector - Detailed analysis
  • CsvMetricsCollector - Spreadsheet reports
  • Custom Collectors - Your monitoring service

✅ Custom Validation

Extend the validation system:

  • Built-in validation rules
  • Custom validator implementation
  • Checksum and integrity checking
  • Migration script validation

Quick Start

Custom Logger Example 

import { ILogger } from '@migration-script-runner/core';

class MyLogger implements ILogger {
  log(message: string): void {
    // Your implementation
  }

  warn(message: string): void {
    // Your implementation
  }

  error(message: string): void {
    // Your implementation
  }
}

const executor = new MigrationScriptExecutor({ handler, 
  logger: new MyLogger()
});

Custom Render Strategy Example 

import { IRenderStrategy } from '@migration-script-runner/core';

class MyRenderStrategy implements IRenderStrategy {
  renderPending(scripts: MigrationScript[]): void {
    // Your custom rendering
  }
  // ... implement other methods
}

const renderer = new MigrationRenderer(
  new MyRenderStrategy(),
  logger,
  config
);

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