## Installation
Install using your favorite package manager:
```bash
npm install @littlethings/log
```
## Usage
### Configuration
#### Programmatic
To configure LittleLog using the `configure` function, see the following example.#
```ts
import { configure, LogLevel } from "littlelog";
configure({
/**
* How verbose the logging should be.
* Defaults to `process.env.LOG_LEVEL`.
*/
level: LogLevel.Info,
/**
* An optional filter used to filter logs based on prefix.
* Defaults to `undefined`.
*/
filter: "my-prefix",
/**
* Whether or not to log prefixes before messages.
* Defaults to `true`.
*/
prefix: false,
/**
* Whether or not to log timestamps.
* Defaults to `true`.
*/
timestamp: false,
/**
* Whether or not to enable color logging.
* Defaults to `true` if in a TTY, otherwise defaults to `false`.
*/
color: false,
/**
* Whether or not to enable icons in logs.
* Defaults to `false`.
*/
icons: true,
});
```
#### Environment Variables
Default values can be supplied via the environment, but they may be
overriden by programmatic configuration as seen above.
```shell
# Set the log level (options are: SILENT, INFO, DEBUG, TRACE).
LOG_LEVEL=INFO
# Don't log prefixes.
LOG_PREFIX=false
# Enable timestamps.
LOG_TIMESTAMP=true
# Filter logs based on prefix regex.
LOG_FILTER="^my-app$"
# You can use the more common `DEBUG` variable for filtering if you prefer.
#DEBUG="^my-app$"
# Enable color.
LOG_COLOR=true
# Disable color.
LOG_COLOR=false
# Or, for compatibility with Chalk, you can use `FORCE_COLOR`.
FORCE_COLOR=1
FORCE_COLOR=0
# Enable icons.
LOG_ICONS=true
```
### Logging
To log messages using the base logger, see the following example.
```ts
import log from "littlelog";
log.info("This is an info log.");
log.debug("This is a debug log.");
log.trace("This is a trace log.");
log.warn("This is a warn log.");
log.error("This is an error log.");
log.fatal("This is a fatal log.");
```
To create a child logger with a unique prefix, see the following example.
```ts
import littlelog from "littlelog";
// This will have the prefix `MyLogger`.
const myLogger = littlelog.child("MyLogger");
myLogger.info("This is an info log.");
myLogger.debug("This is a debug log.");
myLogger.trace("This is a trace log.");
myLogger.warn("This is a warn log.");
myLogger.error("This is an error log.");
myLogger.fatal("This is a fatal log.");
// You can continue to create child loggers if you want!
// This will have the prefix `MyLogger:MySubLogger`.
const mySubLogger = littlelog.child("MySubLogger");
mySubLogger.info("This is an info log.");
mySubLogger.debug("This is a debug log.");
mySubLogger.trace("This is a trace log.");
mySubLogger.warn("This is a warn log.");
mySubLogger.error("This is an error log.");
mySubLogger.fatal("This is a fatal log.");
```
---
_Source: https://npm.io/package/@littlethings/log · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._