README
@cisl/logger
This is a NPM module that wraps around the winston logging
library to take advantage of the cog.json
file for configuration. This allows for easier usage
within cogs as it does not require knowing the boilerplate of using winston and the parts of the
cog.json
. This is largely compatible with the existing function/usage of @cel/logger
.
Installation
npm install @cisl/logger
Usage
const logger = require('@cisl/logger');
logger.debug('debug');
logger.verbose(1);
logger.info('info');
logger.warn({test: 'aaaa', foo: 'bar'});
logger.error('error');
logger.setLogLevel('warn');
logger.logExpression('some message', 'info');
logger.logExpression('some error', 0);
Note: For logging throw exceptions, you should either cast it to a string (e.g.
logger.info(`${new Error('test')}`))
) or pass specific parts of the
exception as strings:
const err = new Error('test');
logger.error(err.message);
logger.error(err.stack);
Attempting to log the Error object as-is will end up with just logging undefined
.
Configuration
As stated above, the logger uses the cog.json
file in the current working
directory to configure itself. By default, the logger will always log to console
and be set to a level of info
. This can be tuned, as well as adding additional
transports, by adding a logging
block to the cog.json
, using the following keys:
{
logging: {
info: "level" // String specifying level to log at, defaults to 'info'
console: true | false // Boolean flag to turn on/off console logging, defaults to true.
file: "filename" // string for file to write log to
db: true | false // Boolean flag to turn on/off logging to MongoDB, defaults to false
}
}
If no cog.json
exists, then it uses a default of log level info
and uses the
console.
Function Signatures
- error(msg: string | object): void
- warn(msg: string | object): void
- info(msg: string | object): void
- debug(msg: string | object): void
- setLogLevel(level: string | number): void
- logExpression(msg: string | object, level: string | number)
Where msg
is the message to log and then level
is a specific log level to use (see below).
Log Levels
The setLogLevel
and logExpression
functions both allow passing in a string or
number to them. Strings should be equal to one of the following available levels:
- error
- warn
- info
- debug
Each of these strings can also be used as the function name on the logger
object:
logger.error(msg);
logger.warn(msg);
logger.info(msg);
logger.verbose(msg);
logger.debug(msg);
logger.silly(msg);
If you use a number, these correspond to the following levels (being backwards
compatible with @cel/logger
):
const levels = {
0: error,
1: warn,
2: info,
3: debug
}