@mter/lazy-logger
Version:
simple console logger insterface to improve performance by lazy string evaluation
72 lines (50 loc) • 1.8 kB
Markdown
# @mter/lazy-logger
Simple console logger to improve performance with lazy string evaluation.
## How to use
### Control the logging with levels
``` typescript
/**
* the log level is taken from the env variable "_LOG_LEVEL"
* log level could be any integer between 0 - 50
* TRACE = 0,
* DEBUG = 10,
* INFO = 20,
* WARN = 30,
* ERROR = 40,
* SEVERE = 50
*/
// _LOG_LEVEL = 20
import { LOGGER } from "@mter/lazy-logger"
LOGGER.severe(()=>"This is my severe log message") // print "This is my severe log message"
LOGGER.error(()=>"This is my error log message") // print "This is my error log message"
LOGGER.warn(()=>"This is my warning log message") // print "This is my warning log message"
LOGGER.info(()=>"This is my info log message") // print "This is my info log message"
LOGGER.debug(()=>"This is my log message") // print nothing
LOGGER.trace(()=>"This is my log message") // print nothing
```
### Change what's printed depending on the current log level
``` typescript
LOGGER.info((loglevel) => {
if (loglevel < LEVEL.INFO)
return [
"This is my special message when log level is info",
{
/* some details object */
},
];
return ["This is my default message"]
});
```
### Set log level programatically
``` typescript
import { LOGGER, LEVEL } from "@mtr/lazy-logger"
...
LOGGER.setLogLevel(LEVEL.DEBUG);
```
### Check is a given log level is loggable with current logger configuration
``` typescript
import { LOGGER, LEVEL } from "@mtr/lazy-logger"
...
// check if DEBUG logs are loggable. If the current log level is higher than DEBUG. this will return false;
const isDebugLoggable: boolean = LOGGER.isLogLevelLoggable(LEVEL.DEBUG);
```