@amplication/logging-utils

util-logging

This library was generated with Nx.

Building

Run nx build util-logging to build the library.

Running unit tests

Run nx test util-logging to execute the unit tests via Jest.

Getting started

Logging in libraries

Libraries should always log without relying on a logger framework. In order to do so, libraries should rely on the ILogger interface and any service/application will pass the proper logger class.

// library.class.ts
import { ILogger } from "@amplication/util/logging";

export class CakeFactory {
    constructor(private readonly logger: ILogger){}

    printInLog(message: string){
        this.logger.info(message)
        this.logger.error(message, new Error())
    }
}

Logging in services / applications

In your microservices, import the logger module and consume it in your root module.

// module.ts

import { Logger } from '@amplication/util/logging';

const logger = new Logger ({
  isProduction: true,
  component: "component-name",
  logLevel: LogLevel.Warn
})

const logMe = () => {
    logger.info("An info log message", { other: { value: 1 }})
    // ....
}

The minimum log level can be configured also with the LOG_LEVEL environment variable, instead of the logLevel: LogLevel.Warn, to one of the following values:

• debug
• info
• warn
• error

Testing utilsutils

A mocked provider can be used in unit tests. The following example explain how to use it

/// myservice.spec.ts

import { MockedLogger } from "@amplication/util/logging/test-utils";

//...
it('', () => {
    const target = new Service(MockedLogger);
})
//...