From 5e9b246bea7043925e54c10910d01f2de3be9015 Mon Sep 17 00:00:00 2001
From: David Bariod <davidriod@googlemail.com>
Date: Wed, 27 Feb 2019 13:02:20 +0100
Subject: [PATCH] Add a CallerPrettyfier callback to the json formatter

---
 entry.go          |  2 +-
 json_formatter.go | 21 +++++++++++++++++++--
 logrus_test.go    | 13 ++++++++++++-
 3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/entry.go b/entry.go
index c5b489e97..fd377286c 100644
--- a/entry.go
+++ b/entry.go
@@ -392,4 +392,4 @@ func (entry *Entry) Panicln(args ...interface{}) {
 func (entry *Entry) sprintlnn(args ...interface{}) string {
 	msg := fmt.Sprintln(args...)
 	return msg[:len(msg)-1]
-}
\ No newline at end of file
+}
diff --git a/json_formatter.go b/json_formatter.go
index 260575359..c494d073d 100644
--- a/json_formatter.go
+++ b/json_formatter.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"runtime"
 )
 
 type fieldKey string
@@ -42,6 +43,12 @@ type JSONFormatter struct {
 	// }
 	FieldMap FieldMap
 
+	// CallerPrettyfier can be set by the user to modify the content
+	// of the function and file keys in the json data when ReportCaller is
+	// activated. If any of the returned value is the empty string the
+	// corresponding key will be removed from json fields.
+	CallerPrettyfier func(*runtime.Frame) (function string, file string)
+
 	// PrettyPrint will indent all json logs
 	PrettyPrint bool
 }
@@ -82,8 +89,18 @@ func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 	data[f.FieldMap.resolve(FieldKeyMsg)] = entry.Message
 	data[f.FieldMap.resolve(FieldKeyLevel)] = entry.Level.String()
 	if entry.HasCaller() {
-		data[f.FieldMap.resolve(FieldKeyFunc)] = entry.Caller.Function
-		data[f.FieldMap.resolve(FieldKeyFile)] = fmt.Sprintf("%s:%d", entry.Caller.File, entry.Caller.Line)
+		funcVal := entry.Caller.Function
+		fileVal := fmt.Sprintf("%s:%d", entry.Caller.File, entry.Caller.Line)
+		if f.CallerPrettyfier != nil {
+			funcVal, fileVal = f.CallerPrettyfier(entry.Caller)
+			fmt.Println(funcVal, fileVal)
+		}
+		if funcVal != "" {
+			data[f.FieldMap.resolve(FieldKeyFunc)] = funcVal
+		}
+		if fileVal != "" {
+			data[f.FieldMap.resolve(FieldKeyFile)] = fileVal
+		}
 	}
 
 	var b *bytes.Buffer
diff --git a/logrus_test.go b/logrus_test.go
index f6fe8bf9a..47a386f95 100644
--- a/logrus_test.go
+++ b/logrus_test.go
@@ -40,7 +40,18 @@ func TestReportCallerWhenConfigured(t *testing.T) {
 		assert.Equal(t, "testWithCaller", fields["msg"])
 		assert.Equal(t, "info", fields["level"])
 		assert.Equal(t,
-			"github.com/sirupsen/logrus_test.TestReportCallerWhenConfigured.func3", fields["func"])
+			"github.com/sirupsen/logrus_test.TestReportCallerWhenConfigured.func3", fields[FieldKeyFunc])
+	})
+
+	LogAndAssertJSON(t, func(log *Logger) {
+		log.ReportCaller = true
+		log.Formatter.(*JSONFormatter).CallerPrettyfier = func(f *runtime.Frame) (string, string) {
+			return "somekindoffunc", "thisisafilename"
+		}
+		log.Print("testWithCallerPrettyfier")
+	}, func(fields Fields) {
+		assert.Equal(t, "somekindoffunc", fields[FieldKeyFunc])
+		assert.Equal(t, "thisisafilename", fields[FieldKeyFile])
 	})
 }