responses to review comments

- empty string as marker for failure to discover calling function
 - tighten up logger usage - don't rely on std logger internally

Also fix ordering of expected/got in logrus_test.go to ensure correct
output form test failures.

entry.go

@@ -123,7 +123,7 @@ func getCaller() (method string) {
 	}
 
 	// if we got here, we failed to find the caller's context
-	return "UNKNOWN_CALLER"
+	return ""
 }
 
 // This function is not declared with a pointer value because otherwise
@@ -133,7 +133,7 @@ func (entry Entry) log(level Level, msg string) {
 	entry.Time = time.Now()
 	entry.Level = level
 	entry.Message = msg
-	if ReportCaller() {
+	if entry.Logger.ReportCaller {
 		entry.Caller = getCaller()
 	}
 	if err := entry.Logger.Hooks.Fire(level, &entry); err != nil {

exported.go

@@ -27,20 +27,14 @@ func SetFormatter(formatter Formatter) {
 	std.Formatter = formatter
 }
 
-// SetReportCaller sets whether to include the calling method as a field
+// SetReportCaller sets whether the standard logger will include the calling
+// method as a field.
 func SetReportCaller(include bool) {
 	std.mu.Lock()
 	defer std.mu.Unlock()
 	std.ReportCaller = include
 }
 
-// ReportCaller returns the 'include calling method' state
-func ReportCaller() bool {
-	std.mu.Lock()
-	defer std.mu.Unlock()
-	return std.ReportCaller
-}
-
 // SetLevel sets the standard logger level.
 func SetLevel(level Level) {
 	std.mu.Lock()

formatter.go

@@ -31,7 +31,7 @@ type Formatter interface {
 //
 // It's not exported because it's still using Data in an opinionated way. It's to
 // avoid code duplication between the two default formatters.
-func prefixFieldClashes(data Fields) {
+func prefixFieldClashes(data Fields, reportCaller bool) {
 	if t, ok := data["time"]; ok {
 		data["fields.time"] = t
 	}
@@ -44,8 +44,8 @@ func prefixFieldClashes(data Fields) {
 		data["fields.level"] = l
 	}
 
-	// If Reportmethod is not set, 'method' will not conflict.
-	if ReportCaller() {
+	// If reportCaller is not set, 'method' will not conflict.
+	if reportCaller {
 		if l, ok := data["method"]; ok {
 			data["fields.method"] = l
 		}

json_formatter.go

@@ -52,7 +52,13 @@ func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 			data[k] = v
 		}
 	}
-	prefixFieldClashes(data)
+
+	reportCaller := false
+	if entry.Logger != nil {
+		reportCaller = entry.Logger.ReportCaller
+	}
+
+	prefixFieldClashes(data, reportCaller)
 
 	timestampFormat := f.TimestampFormat
 	if timestampFormat == "" {
@@ -62,7 +68,7 @@ func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 	data[f.FieldMap.resolve(FieldKeyTime)] = entry.Time.Format(timestampFormat)
 	data[f.FieldMap.resolve(FieldKeyMsg)] = entry.Message
 	data[f.FieldMap.resolve(FieldKeyLevel)] = entry.Level.String()
-	if ReportCaller() {
+	if reportCaller {
 		data[f.FieldMap.resolve(FieldKeyCaller)] = entry.Caller
 	}
 	serialized, err := json.Marshal(data)

json_formatter_test.go

@@ -193,6 +193,7 @@ func TestFieldDoesNotClashWithCaller(t *testing.T) {
 func TestFieldClashWithCaller(t *testing.T) {
 	SetReportCaller(true)
 	formatter := &JSONFormatter{}
+	std.ReportCaller = true
 
 	b, err := formatter.Format(WithField("method", "howdy pardner"))
 	if err != nil {

logrus_test.go

@@ -60,32 +60,30 @@ func LogAndAssertText(t *testing.T, log func(*Logger), assertions func(fields ma
 // is added, and when it is unset it is not set or modified
 func TestReportCaller(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
-		SetReportCaller(false)
+		log.ReportCaller = false
 		log.Print("testNoCaller")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "testNoCaller")
-		assert.Equal(t, fields["level"], "info")
-		assert.Equal(t, fields["method"], nil)
+		assert.Equal(t, "testNoCaller", fields["msg"])
+		assert.Equal(t, "info", fields["level"])
+		assert.Equal(t, nil, fields["method"])
 	})
 
 	LogAndAssertJSON(t, func(log *Logger) {
-		SetReportCaller(true)
+		log.ReportCaller = true
 		log.Print("testWithCaller")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "testWithCaller")
-		assert.Equal(t, fields["level"], "info")
-		assert.Equal(t, fields["method"], "testing.tRunner")
+		assert.Equal(t, "testWithCaller", fields["msg"])
+		assert.Equal(t, "info", fields["level"])
+		assert.Equal(t, "testing.tRunner", fields["method"])
 	})
-
-	SetReportCaller(false) // return to default value
 }
 
 func TestPrint(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Print("test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test")
-		assert.Equal(t, fields["level"], "info")
+		assert.Equal(t, "test", fields["msg"])
+		assert.Equal(t, "info", fields["level"])
 	})
 }
 
@@ -93,8 +91,8 @@ func TestInfo(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Info("test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test")
-		assert.Equal(t, fields["level"], "info")
+		assert.Equal(t, "test", fields["msg"])
+		assert.Equal(t, "info", fields["level"])
 	})
 }
 
@@ -102,8 +100,8 @@ func TestWarn(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Warn("test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test")
-		assert.Equal(t, fields["level"], "warning")
+		assert.Equal(t, "test", fields["msg"])
+		assert.Equal(t, "warning", fields["level"])
 	})
 }
 
@@ -111,7 +109,7 @@ func TestInfolnShouldAddSpacesBetweenStrings(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Infoln("test", "test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test test")
+		assert.Equal(t, "test test", fields["msg"])
 	})
 }
 
@@ -119,7 +117,7 @@ func TestInfolnShouldAddSpacesBetweenStringAndNonstring(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Infoln("test", 10)
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test 10")
+		assert.Equal(t, "test 10", fields["msg"])
 	})
 }
 
@@ -127,7 +125,7 @@ func TestInfolnShouldAddSpacesBetweenTwoNonStrings(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Infoln(10, 10)
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "10 10")
+		assert.Equal(t, "10 10", fields["msg"])
 	})
 }
 
@@ -135,7 +133,7 @@ func TestInfoShouldAddSpacesBetweenTwoNonStrings(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Infoln(10, 10)
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "10 10")
+		assert.Equal(t, "10 10", fields["msg"])
 	})
 }
 
@@ -143,7 +141,7 @@ func TestInfoShouldNotAddSpacesBetweenStringAndNonstring(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Info("test", 10)
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test10")
+		assert.Equal(t, "test10", fields["msg"])
 	})
 }
 
@@ -151,7 +149,7 @@ func TestInfoShouldNotAddSpacesBetweenStrings(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.Info("test", "test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "testtest")
+		assert.Equal(t, "testtest", fields["msg"])
 	})
 }
 
@@ -189,7 +187,7 @@ func TestUserSuppliedFieldDoesNotOverwriteDefaults(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.WithField("msg", "hello").Info("test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test")
+		assert.Equal(t, "test", fields["msg"])
 	})
 }
 
@@ -197,8 +195,8 @@ func TestUserSuppliedMsgFieldHasPrefix(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.WithField("msg", "hello").Info("test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["msg"], "test")
-		assert.Equal(t, fields["fields.msg"], "hello")
+		assert.Equal(t, "test", fields["msg"])
+		assert.Equal(t, "hello", fields["fields.msg"])
 	})
 }
 
@@ -206,7 +204,7 @@ func TestUserSuppliedTimeFieldHasPrefix(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.WithField("time", "hello").Info("test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["fields.time"], "hello")
+		assert.Equal(t, "hello", fields["fields.time"])
 	})
 }
 
@@ -214,8 +212,8 @@ func TestUserSuppliedLevelFieldHasPrefix(t *testing.T) {
 	LogAndAssertJSON(t, func(log *Logger) {
 		log.WithField("level", 1).Info("test")
 	}, func(fields Fields) {
-		assert.Equal(t, fields["level"], "info")
-		assert.Equal(t, fields["fields.level"], 1.0) // JSON has floats only
+		assert.Equal(t, "info", fields["level"])
+		assert.Equal(t, 1.0, fields["fields.level"]) // JSON has floats only
 	})
 }
 
@@ -259,8 +257,8 @@ func TestDoubleLoggingDoesntPrefixPreviousFields(t *testing.T) {
 	err = json.Unmarshal(buffer.Bytes(), &fields)
 	assert.NoError(t, err, "should have decoded second message")
 	assert.Equal(t, len(fields), 4, "should only have msg/time/level/context fields")
-	assert.Equal(t, fields["msg"], "omg it is!")
-	assert.Equal(t, fields["context"], "eating raw fish")
+	assert.Equal(t, "omg it is!", fields["msg"])
+	assert.Equal(t, "eating raw fish", fields["context"])
 	assert.Nil(t, fields["fields.msg"], "should not have prefixed previous `msg` entry")
 
 }
@@ -269,10 +267,10 @@ func TestNestedLoggingReportsCorrectCaller(t *testing.T) {
 	var buffer bytes.Buffer
 	var fields Fields
 
-	SetReportCaller(true)
 	logger := New()
 	logger.Out = &buffer
 	logger.Formatter = new(JSONFormatter)
+	logger.ReportCaller = true
 
 	llog := logger.WithField("context", "eating raw fish")
 
@@ -281,9 +279,9 @@ func TestNestedLoggingReportsCorrectCaller(t *testing.T) {
 	err := json.Unmarshal(buffer.Bytes(), &fields)
 	assert.NoError(t, err, "should have decoded first message")
 	assert.Equal(t, len(fields), 5, "should have msg/time/level/method/context fields")
-	assert.Equal(t, fields["msg"], "looks delicious")
-	assert.Equal(t, fields["context"], "eating raw fish")
-	assert.Equal(t, fields["method"], "testing.tRunner")
+	assert.Equal(t, "looks delicious", fields["msg"])
+	assert.Equal(t, "eating raw fish", fields["context"])
+	assert.Equal(t, "testing.tRunner", fields["method"])
 
 	buffer.Reset()
 
@@ -311,7 +309,7 @@ func TestNestedLoggingReportsCorrectCaller(t *testing.T) {
 	assert.Nil(t, fields["fields.msg"], "should not have prefixed previous `msg` entry")
 	assert.Equal(t, "testing.tRunner", fields["method"])
 
-	SetReportCaller(false) // return to default value
+	logger.ReportCaller = false // return to default value
 }
 
 func TestConvertLevelToString(t *testing.T) {

text_formatter.go

@@ -72,7 +72,12 @@ func (f *TextFormatter) Format(entry *Entry) ([]byte, error) {
 		b = &bytes.Buffer{}
 	}
 
-	prefixFieldClashes(entry.Data)
+	reportCaller := false
+	if entry.Logger != nil {
+		reportCaller = entry.Logger.ReportCaller
+	}
+
+	prefixFieldClashes(entry.Data, reportCaller)
 
 	isColorTerminal := isTerminal && (runtime.GOOS != "windows")
 	isColored := (f.ForceColors || isColorTerminal) && !f.DisableColors
@@ -88,7 +93,7 @@ func (f *TextFormatter) Format(entry *Entry) ([]byte, error) {
 			f.appendKeyValue(b, "time", entry.Time.Format(timestampFormat))
 		}
 		f.appendKeyValue(b, "level", entry.Level.String())
-		if ReportCaller() {
+		if reportCaller {
 			f.appendKeyValue(b, "method", entry.Caller)
 		}
 		if entry.Message != "" {
@@ -119,7 +124,13 @@ func (f *TextFormatter) printColored(b *bytes.Buffer, entry *Entry, keys []strin
 	levelText := strings.ToUpper(entry.Level.String())[0:4]
 
 	caller := ""
-	if ReportCaller() {
+
+	reportCaller := false
+	if entry.Logger != nil {
+		reportCaller = entry.Logger.ReportCaller
+	}
+
+	if reportCaller {
 		caller = fmt.Sprintf(" %s()", entry.Caller)
 	}