Add docstrings

Author: LeartS

lib/log.js

@@ -28,6 +28,9 @@ const defaultLevelFormatter = (level) => {
 
 const defaultTemplate = '[%t] %l [%n]:'
 
+// "Nice" default options, they make log lines like:
+// [2019-02-18T00:37:56.007] WARN [root]: This is a warning message
+// With colored log level, according to serverity.
 const defaultOptions = {
   levelFormatter: defaultLevelFormatter,
   timestampFormatter: defaultTimestampFormatter,
@@ -38,13 +41,31 @@ const defaultOptions = {
 
 const _loggersByName = {}
 
+/**
+ * Subclass of loglevel's Logger,
+ * Preset to use loglevel-plugin-prefix with some nice default options.
+ * Can obtain child loggers by calling .getLogger, they will inherit
+ * parent's options.
+ */
 class MonkLogger extends logLevel.constructor {
   constructor (name, level, options) {
     super(name, level)
     this.options = {...defaultOptions}
     this.configure(options)
   }
 
+  /**
+   * Configure the logger, accepts all loglevel-plugin-prefix options
+   * and the loglevel (`level` key).
+   *
+   * @param {object} options - new option values to update
+   * @param {boolean} [reset=false] - if false (the default), it will keep
+   *   and update current options (e.g. options inherited from parents or
+   *   a previous call to configure). When true, if will first reset options
+   *   to default ones, and then update with supplied ones.
+   *   Therefore, you can use .configure({}, true) to completely reset
+   *   options to defaults.
+   */
   configure (options, reset = false) {
     this.options = {
       ...(reset ? defaultOptions : this.options),
@@ -54,6 +75,12 @@ class MonkLogger extends logLevel.constructor {
     prefix.apply(this, this.options)
   }
 
+  /**
+   *
+   * @param {string} name - child logger name
+   * @param {string} level - only output log messages of at least this level
+   * @param {object} options - loglevel-plugin-prefix options
+   */
   getLogger (name, level, options) {
     if (typeof name !== "string" || name === "") {
       throw new TypeError("You must supply a name when creating a logger.")
@@ -72,4 +99,6 @@ prefix.reg(logLevel)
 const defaultLogger = new MonkLogger('root')
 defaultLogger.getLoggers = () => _loggersByName
 
+// Export default logger. Can be used directly, or can be used
+// to obtain child loggers.
 module.exports = defaultLogger