From 13b17eff16fa1bc078162866211973f19a14b80d Mon Sep 17 00:00:00 2001
From: Binaek Sarkar <binaek@turbot.com>
Date: Tue, 21 Dec 2021 17:11:44 +0530
Subject: [PATCH] add support for custom time function

---
 global.go      |  2 ++
 intlogger.go   | 12 ++++++------
 logger.go      |  7 +++++--
 logger_test.go |  4 ++--
 4 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/global.go b/global.go
index 22ebc57..36888fd 100644
--- a/global.go
+++ b/global.go
@@ -2,6 +2,7 @@ package hclog
 
 import (
 	"sync"
+	"time"
 )
 
 var (
@@ -14,6 +15,7 @@ var (
 	DefaultOptions = &LoggerOptions{
 		Level:  DefaultLevel,
 		Output: DefaultOutput,
+		TimeFn: func() time.Time { return time.Now() },
 	}
 )
 
diff --git a/intlogger.go b/intlogger.go
index 4b9b531..2d63fae 100644
--- a/intlogger.go
+++ b/intlogger.go
@@ -60,7 +60,7 @@ type intLogger struct {
 	callerOffset int
 	name         string
 	timeFormat   string
-	useUtcTime   bool
+	timeFn       TimeFunction
 	disableTime  bool
 
 	// This is an interface so that it's shared by any derived loggers, since
@@ -117,7 +117,7 @@ func newLogger(opts *LoggerOptions) *intLogger {
 		json:              opts.JSONFormat,
 		name:              opts.Name,
 		timeFormat:        TimeFormat,
-		useUtcTime:        opts.UTCTime,
+		timeFn:            func() time.Time { return time.Now() },
 		disableTime:       opts.DisableTime,
 		mutex:             mutex,
 		writer:            newWriter(output, opts.Color),
@@ -132,6 +132,9 @@ func newLogger(opts *LoggerOptions) *intLogger {
 	if l.json {
 		l.timeFormat = TimeFormatJSON
 	}
+	if opts.TimeFn != nil {
+		l.timeFn = opts.TimeFn
+	}
 	if opts.TimeFormat != "" {
 		l.timeFormat = opts.TimeFormat
 	}
@@ -154,10 +157,7 @@ func (l *intLogger) log(name string, level Level, msg string, args ...interface{
 		return
 	}
 
-	t := time.Now()
-	if l.useUtcTime {
-		t = t.UTC()
-	}
+	t := l.timeFn()
 
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
diff --git a/logger.go b/logger.go
index d16a7e3..0a3f606 100644
--- a/logger.go
+++ b/logger.go
@@ -5,6 +5,7 @@ import (
 	"log"
 	"os"
 	"strings"
+	"time"
 )
 
 var (
@@ -219,6 +220,8 @@ type StandardLoggerOptions struct {
 	ForceLevel Level
 }
 
+type TimeFunction = func() time.Time
+
 // LoggerOptions can be used to configure a new logger.
 type LoggerOptions struct {
 	// Name of the subsystem to prefix logs with
@@ -248,8 +251,8 @@ type LoggerOptions struct {
 	// The time format to use instead of the default
 	TimeFormat string
 
-	// Control whether to use UTC instead of the default local time-zone
-	UTCTime bool
+	// A function which is called to get the time object that is formatted using `TimeFormat`
+	TimeFn TimeFunction
 
 	// Control whether or not to display the time at all. This is required
 	// because setting TimeFormat to empty assumes the default format.
diff --git a/logger_test.go b/logger_test.go
index 57cfa55..b098b7e 100644
--- a/logger_test.go
+++ b/logger_test.go
@@ -256,7 +256,7 @@ func TestLogger(t *testing.T) {
 			Name:       "test",
 			Output:     &buf,
 			TimeFormat: time.Kitchen,
-			UTCTime:    true,
+			TimeFn:     func() time.Time { return time.Now().UTC() },
 		})
 
 		logger.Info("this is test", "who", "programmer", "why", "testing is fun")
@@ -683,7 +683,7 @@ func TestLogger_JSON(t *testing.T) {
 			Output:     &buf,
 			JSONFormat: true,
 			TimeFormat: time.Kitchen,
-			UTCTime:    true,
+			TimeFn:     func() time.Time { return time.Now().UTC() },
 		})
 
 		logger.Info("Lacatan banana")