feat: add timestamps to log lines through _LOG_TIMESTAMP environment …

…variable

lib/logging.js

@@ -1,12 +1,15 @@
 import npmlog from 'npmlog';
 import _ from 'lodash';
 import { unleakString } from './util';
+import moment from 'moment';
 
 
 // levels that are available from `npmlog`
 const NPM_LEVELS = ['silly', 'verbose', 'debug', 'info', 'http', 'warn', 'error'];
 const MAX_LOG_RECORDS_COUNT = 3000;
 
+const PREFIX_TIMESTAMP_FORMAT = 'HH-mm-ss:SSS';
+
 // mock log object used in testing mode
 let mockLog = {};
 for (let level of NPM_LEVELS) {
@@ -41,6 +44,14 @@ function _getLogger () {
   return [logger, usingGlobalLog];
 }
 
+function getActualPrefix (prefix, logTimestamp = false) {
+  let actualPrefix = _.isFunction(prefix) ? prefix() : prefix;
+  if (logTimestamp) {
+    actualPrefix = `[${moment().format(PREFIX_TIMESTAMP_FORMAT)}] ${actualPrefix}`;
+  }
+  return actualPrefix;
+}
+
 function getLogger (prefix = null) {
   let [logger, usingGlobalLog] = _getLogger();
 
@@ -55,10 +66,12 @@ function getLogger (prefix = null) {
     configurable: true
   });
 
+  const logTimestamp = parseInt(process.env._LOG_TIMESTAMP, 10) === 1;
+
   // add all the levels from `npmlog`, and map to the underlying logger
   for (const level of NPM_LEVELS) {
     wrappedLogger[level] = function (...args) {
-      const actualPrefix = _.isFunction(prefix) ? prefix() : prefix;
+      const actualPrefix = getActualPrefix(prefix, logTimestamp);
       for (const arg of args) {
         const out = (_.isError(arg) && arg.stack) ? arg.stack : `${arg}`;
         for (const line of out.split('\n')) {

package.json

@@ -43,6 +43,7 @@
     "md5-file": "^4.0.0",
     "mjpeg-server": "^0.3.0",
     "mkdirp": "^0.5.1",
+    "moment": "^2.24.0",
     "mv": "^2.1.1",
     "ncp": "^2.0.0",
     "npmlog": "^4.1.2",