Function createLoggerMiddleware

Create a logger middleware for debugging

Creates middleware that logs request and response information. Supports multiple output formats and custom filtering.

Example: Basic logging (default format)

import { createFej, createLoggerMiddleware } from 'fej';

const api = createFej();
api.use('logger', createLoggerMiddleware());
// Output: → GET https://api.example.com/users
//         ← GET https://api.example.com/users - 200 (123ms)
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Example: JSON format

api.use('logger', createLoggerMiddleware({
  format: 'json',
}));
// Output: {"type":"request","method":"GET","url":"...","timestamp":"..."}
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Example: Detailed format with headers

api.use('logger', createLoggerMiddleware({
  format: 'detailed',
  logRequest: true,
  logResponse: true,
}));
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Example: Custom formatter

api.use('logger', createLoggerMiddleware({
  format: (ctx, duration) => {
    return `[${ctx.request.init.method || 'GET'}] ${ctx.request.url} took ${duration}ms`;
  },
}));
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Example: With filtering

api.use('logger', createLoggerMiddleware({
  filter: (ctx) => {
    // Only log POST requests
    return ctx.request.init.method === 'POST';
  },
}));
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