@punkish/zlogger

zlogger

a realy zimple logger

There are a lot of wonderful loggers that do a lot of things. This is not one of them. This is a zero-dependency, 3.9KB (135 lines), synchronous logger, basically just a wrapper around process.stdout.write. It has loglevels and transports and can output log in color.

1. import the logger class. If your script is in a CommonJS format, rename it with .mjs extension.

   import { Zlogger } from '@punkish/zlogger';

2. create a new logger with options

   const log = new Zlogger({
   
       // log levels can be
       //  'debug', 'info', 'warn', 'error', 'fatal'
       //  'info' is the default log level
       level: 'info', 
   
       // transports are where the log is written
       //   'console' always exists in development
       //   'file' is optional
       transports: [ 'console', 'file' ],
   
       // 'mode' is optional and chooses between streams and appendFile,
       // defaulting to streams if none is provided
       mode: 'streams',
   
       // 'dir' is optional and used when transport is 'file'
       // if no 'dir' is provided then 'logs' is used
       dir: 'path/to/logdir',
   
       // 'timestamp' on every log line can be 'timeonly', 'dateonly' or 
       // defaults to 'datetime'
       tsType: 'timeonly'
   });

3. log away

   log.info(`logger level is ${log.level()}`);
   log.info('foo');
   log.info('do something and wait… ', 'start');
   log.info('finished something\n', 'end');
   log.info('no front matter\n', 'end');
   log.warn('oops');
   log.error('uh oh!');
   log.fatal('died');
   log.setLevel('error');
   log.info(`logger level is ${log.level()}`);
   log.info('foo');
   log.info('hello… ', 'start');
   log.info('done\n', 'end');
   log.warn('oops');
   log.error('log-level changed to "error" and above');
   log.fatal('died again');

   The optional 'start' and 'end' position flags output the log message on the same line (in this case, you have to add the \n newline explicitly when the 'pos' is 'end'). If no log invocation with 'start' is provided, but an 'end' is provided, then no front matter is printed.

   In the example shown above, the output will be

   test/index.test.js:() [19] 18:34:16.291 –  INFO logger level is INFO
   test/index.test.js:() [20] 18:34:16.295 –  INFO foo
   test/index.test.js:() [21] 18:34:16.295 –  INFO do something and wait… finished something
   no front matter
   test/index.test.js:() [32] 18:34:16.295 –  WARN oops
   test/index.test.js:() [33] 18:34:16.295 – ERROR uh oh!
   test/index.test.js:() [34] 18:34:16.295 – FATAL died
   test/index.test.js:() [41] 18:34:16.295 – ERROR log-level changed to "error" and above
   test/index.test.js:() [42] 18:34:16.295 – FATAL died again