+function bunyanLogFactory (level: string) {
+ return function (...params: any[]) {
+ let meta = null
+ let args = [].concat(params)
+
+ if (arguments[0] instanceof Error) {
+ meta = arguments[0].toString()
+ args = Array.prototype.slice.call(arguments, 1)
+ args.push(meta)
+ } else if (typeof (args[0]) !== 'string') {
+ meta = arguments[0]
+ args = Array.prototype.slice.call(arguments, 1)
+ args.push(meta)
+ }
+
+ logger[level].apply(logger, args)
+ }
+}
+
+const bunyanLogger = {
+ level: () => { },
+ trace: bunyanLogFactory('debug'),
+ debug: bunyanLogFactory('debug'),
+ verbose: bunyanLogFactory('debug'),
+ info: bunyanLogFactory('info'),
+ warn: bunyanLogFactory('warn'),
+ error: bunyanLogFactory('error'),
+ fatal: bunyanLogFactory('error')
+}
+
+// ---------------------------------------------------------------------------
+
+type LoggerTagsFn = (...tags: string[]) => { tags: string[] }
+function loggerTagsFactory (...defaultTags: string[]): LoggerTagsFn {
+ return (...tags: string[]) => {
+ return { tags: defaultTags.concat(tags) }
+ }
+}
+
+// ---------------------------------------------------------------------------
+
+async function mtimeSortFilesDesc (files: string[], basePath: string) {
+ const promises = []
+ const out: { file: string, mtime: number }[] = []
+
+ for (const file of files) {
+ const p = stat(basePath + '/' + file)
+ .then(stats => {
+ if (stats.isFile()) out.push({ file, mtime: stats.mtime.getTime() })
+ })
+
+ promises.push(p)
+ }
+
+ await Promise.all(promises)
+
+ out.sort((a, b) => b.mtime - a.mtime)
+
+ return out
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+ LoggerTagsFn,
+
+ buildLogger,
+ timestampFormatter,
+ labelFormatter,
+ consoleLoggerFormat,
+ jsonLoggerFormat,
+ mtimeSortFilesDesc,
+ logger,
+ loggerTagsFactory,
+ bunyanLogger
+}
+
+// ---------------------------------------------------------------------------
+
+function removeCyclicValues () {
+ const seen = new WeakSet()
+
+ // Thanks: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Cyclic_object_value#Examples
+ return (key: string, value: any) => {
+ if (key === 'cert') return 'Replaced by the logger to avoid large log message'
+
+ if (typeof value === 'object' && value !== null) {
+ if (seen.has(value)) return
+
+ seen.add(value)
+ }
+
+ if (value instanceof Set) {
+ return Array.from(value)
+ }
+
+ if (value instanceof Map) {
+ return Array.from(value.entries())
+ }
+
+ if (value instanceof Error) {
+ const error = {}
+
+ Object.getOwnPropertyNames(value).forEach(key => { error[key] = value[key] })
+
+ return error
+ }
+
+ return value
+ }
+}
+
+function getAdditionalInfo (info: any) {
+ const toOmit = [ 'label', 'timestamp', 'level', 'message', 'sql', 'tags' ]
+
+ return omit(info, toOmit)
+}