@cork-labs/monkfish-adapter-logger NPM

Monkfish Adapter Logger

Logger adapter for Node.js framework Monkfish.

Getting Started

npm install --save @cork-labs/monkfish @cork-labs/monkfish-adapter-logger

Wraps bunyan logger library to facilitate injection, testing and configuration of logs.

See Monkfish for more information.

API

Logger

`Logger.createLogger(config, data)`

Creates an instance of Logger from configuration.

config: object - of stream instances (OutBunyan, OutConsole, OutFile).
data: object (optional) - permanent log fields (tip: keep it flat).

Example config:

{
  name: 'my-app',
  streams: [
    // append to file (does not create directories, will fail if dirs are missings)
    {
      type: 'file',
      path: './logs/test.log',
      options: { ... } // override options for this stream only
    },
    {
      type: 'bunyan',
      bunyan: { /* Bunyan nativate options */ },
      // options: { ... } are ignored in bunyan stream
    },
    // for debug purposes only, do not use in production
    {
      type: 'console',
      // override options for this stream, e.g.: make console more human friendly
      options: {
        message: true,
        prettyJson: 2,
        dump: true
      }
    },
  ],
  // options for all streams
  options: {
    message: false, // log an extra line with a human readable message before the json payload
    prettyJson: 0, // format json payload (multi-line)
    dump: false // output error stack traces after payload (multi-line)
  }
}

`new Logger(name, streams): void`

Creates an instance of Logger with the pre-configured stream instances.

name: string - added to the log fields as log_n
streams: array - of stream instances (OutBunyan, OutConsole, OutFile).
data: object (optional) - permanent log fields (tip: keep it flat).

`logger.child(data): Logger`

Returns a new logger, containing all the parent configuration and context, plus the provided optional data.

data: object (optional) - additional permanent log fields (tip: keep it flat).

`logger.set(key, value): void`

Adds key/value to permanent fields data or removes key when value not provided.

Avoid adding objects, keep it flat.

key: string
value: any (optional) - If value not provided (or undefined is provided), removes key from permanent fields.

`logger.debug('message', data): void`

Logs a debug level message, with adittional optional fields.

`logger.info(message, data): void`

Logs an info level message, with adittional optional fields.

message: string - logged as log_m.
data: object (optional) - additional fields for this log message only.

`logger.warn('message', data): void`

Logs an warning level message, with adittional optional fields.

message: string - logged as log_m.
data: object (optional) - additional fields for this log message only.

`logger.error('message', data, err): void`

Logs an error level message, with adittional optional fields, plus optional error (ideally a subclass of Error).

message: string - logged as log_m.
data: object (optional) - additional fields for this log message only.

If error is a subclass of Error, only the following key/values are added to the log.

err_name: err.constructor.name
err_msg: err.message
err_trace: err.stack

Otherwise, it is directly logged under the err key.

`logger.flat(prefix, obj): object`

Flattens the object for logging, use on data objects before you log them to keep them flat.

prefix: string - e.g. user.
data: object (optional) - additional fields for this log message only.
ret: object (optional) - if provided, fields are flattened into this object.

// flattening one object
const flatUser = logger.flat('todo', todo);
logger.info('todo.created', data);

// { log_m: 'todo.created', ..., todo_id: ..., todo_title: ... }

// flattening two objects into one
const data = logger.flat('article', article, {});
logger.flat('tag', tag, data)
logger.info('article.tags.created', data);

// { log_m: 'article.tags.created', ..., todo_id: ..., todo_title: ..., tag_id: ..., tag_title: ... }

Develop

# lint and fix
npm run lint

# run test suite
npm test

# lint and test
npm run build

# serve test coverage
npm run coverage

# publish a minor version
node_modules/.bin/npm-bump minor