@midwayjs/logger


@midwayjs/logger is a log module for midway project.

Required

Node.js >= v20 since v4.0.0

Install

``bash
$ npm install @midwayjs/logger --save
`

Create Logger

`ts
import { loggers } from '@midwayjs/logger';

const logger = loggers.createLogger('logger', {
// some logger options
})
`

Create With Transport

Create logger with console and file transports instance.

`typescript
import { loggers, ConsoleTransport, FileTransport } from '@midwayjs/logger';

const logger = loggers.createLogger('logger', {
transports: {
console: new ConsoleTransport(),
file: new FileTransport({
dir: '...',
fileLogName: 'app.log',
}),
}
})
`

Create console logger.

`typescript
const logger = loggers.createLogger('consoleLogger', {
transports: {
console: new ConsoleTransport(),
}
})
`

Create logger with options mode.

`typescript
const logger = loggers.createLogger('consoleLogger', {
transports: {
console: {
autoColors: true,
},
file: {
dir: '...',
fileLogName: 'app.log',
}
}
})
`

Logger Output Method

`ts
logger.debug('debug info');
logger.info('启动耗时 %d ms', Date.now() - start);
logger.warn('warning!');
logger.error(new Error('my error'));
logger.write('abcde');
`

Logger Level

log level is divided into the following categories, and the log level decreases sequentially (the larger the number, the lower the level):

`ts
const levels = {
none: 0,
error: 1,
trace: 2,
warn: 3,
info: 4,
verbose: 5,
debug: 6,
silly: 7,
all: 8,
}
`

Set level for all transports

`typescript
const logger = loggers.createLogger('logger', {
// ...
level: 'warn',
});

// not output
logger.debug('debug info');

// not output
logger.info('debug info');
`

Format and ContextFormat

Add logger format and context format.

`typescript
const logger = loggers.createLogger('logger', {
// ...
format: info => {
return ${info.timestamp} ${info.message};
},
contextFormat: info => {
return ${info.timestamp} [${info.ctx.traceId}] ${info.message};
}
});
`

info is a default metadata, include some properties.

Tranports

The actual behavior of the log output we call the transport.The log library has four built-in default Transports.

* ConsoleTransport Output message to stdout and stderr with color.
* FileTransport Output message to file and rotate by self.
* ErrorTransport Inherit FileTransport and only output error message.
* JSONTransport Inherit FileTransport and output json format.

The above Transports are all registered by default and can be configured by the name when registering.

`typescript
const logger = loggers.createLogger('consoleLogger', {
transports: {
console: {/...options/},
file: {/...options/},
error: {/...options/},
json: {/...options/},
}
});
`

Implement a new Transport

Inherit Transport abstract class and implement log and close method.

`typescript
import { Transport, ITransport } from '@midwayjs/logger';

export interface CustomTransportOptions {
// ...
}

export class CustomTransport extends Transport implements ITransport {
log(level: LoggerLevel | false, meta: LogMeta, ...args) {
// save file or post to remote server
}

close() {}
}
`

Register class to TransportManager before used.

`typescript
import { TransportManager } from '@midwayjs/logger';

TransportManager.set('custom', CustomTransport);
`

And you can configure it in your code.

`typescript
const logger = loggers.createLogger('consoleLogger', {
transports: {
custom: {/...options/}
}
});
``

Default Logger Options

find more options in interface.

License

MIT)