LogStructure.ts

types.ts

type ApplicationLog = {
   level: 'debug' | 'info' | 'warning' | 'danger' | 'critical',
   message: string,
   createdAt: number,
   userId?: string,
   // a business metric, e.g. SIGNUP
   action?: string, 
   monetaryValue?: number,
   requestId?: string,

   // Common fields depending on your use case
   oldValue?: string,
   value?: string,
   comment?: string,

   // Handle custom cases
   [key: string]: any;
}

// You typically don't control this type yourself. 
// It's determined by your hosting provider. But
// it typically includes at least this info.
type HTTPLog = {
   request: {
      method: 'GET' | 'POST' | 'PATCH' | 'DELETE' | 'PUT',
      path: string,
      query?: string,
      ipAddress: string,
      headers: {
          requestId?: string,
      }
      // ...
   },
   response: {
      httpStatus: number,   
      responseTime: number,
      // ...
   }
}