appium-logger

appium-logger

Basic logger defaulting to npmlog with special consideration for running tests (doesn't output logs when run with _TESTING=1 in the env).

Logging levels

There are a number of levels, exposed as methods on the log object, at which logging can be made. The built-in ones correspond to those of npmlog, and are: silly, verbose, info, http, warn, and error. In addition there is a debug level.

The default threshhold level is verbose.

The logged output, by default, will be level prefix message. So

import { getLogger } from 'appium-logger';
let log = getLogger('mymodule');
log.warn('a warning');`

Will produce

warn mymodule a warning

Environment variables

There are two environment variable flags that affect the way appium-logger works.

_TESTING

• _TESTING=1 stops output of logs when set to 1.

_FORCE_LOGS

• This flag, when set to 1, reverses the _TESTING

Usage

log.level

• get and set the threshhold level at which to display the logs. Any logs at or above this level will be displayed. The special level silent will prevent anything from being displayed ever. See npmlog#level.

log[level](message)

• logs to level

  import { getLogger } from 'appium-logger';
  let log = getLogger('mymodule');
  
  log.info('hi!');
  // => info mymodule hi!
  

log.unwrap()

• retrieves the underlying npmlog object, in order to manage how logging is done at a low level (e.g., changing output streams, retrieving an array of messages, adding log levels, etc.).

  import { getLogger } from 'appium-logger';
  let log = getLogger('mymodule');
  
  log.info('hi!');
  
  let npmlogger = log.unwrap();
  
  // any `npmlog` methods
  let logs = npmlogger.record;
  // logs === [ { id: 0, level: 'info', prefix: 'mymodule', message: 'hi!', messageRaw: [ 'hi!' ] }]
  

log.errorAndThrow(error)

• logs the error passed in, at error level, and then throws the error. If the error passed in is not an instance of Error (either directly, or a subclass of Error) it will be wrapped in a generic Error object.

  import { getLogger } from 'appium-logger';
  let log = getLogger('mymodule');
  
  // previously there would be two lines
  log.error('This is an error');
  throw new Error('This is an error');
  
  // now is compacted
  log.errorAndThrow('This is an error');