Merge pull request #15 from uber-common/ajs-nop

Add constructor for a no-op logger

interface.go

@@ -26,6 +26,7 @@
 package bark
 
 import (
+	"io/ioutil"
 	"time"
 
 	"github.com/cactus/go-statsd-client/statsd"
@@ -84,7 +85,7 @@ type Logger interface {
 	Fields() Fields
 }
 
-// Logfields is an interface for dictionaries passed to Logger's WithFields logging method.
+// LogFields is an interface for dictionaries passed to Logger's WithFields logging method.
 // It exists to provide a layer of indirection so code already using other
 // "Fields" types can be changed to use bark.Logger instances without
 // any refactoring (sidestepping the fact that if we used a concrete
@@ -101,6 +102,15 @@ func (f Fields) Fields() map[string]interface{} {
 	return f
 }
 
+// NewNopLogger creates a no-op logger.
+func NewNopLogger() Logger {
+	return NewLoggerFromLogrus(&logrus.Logger{
+		Out:       ioutil.Discard,
+		Formatter: new(logrus.JSONFormatter),
+		Level:     logrus.DebugLevel,
+	})
+}
+
 // NewLoggerFromLogrus creates a bark-compliant wrapper for a logrus-brand logger.
 func NewLoggerFromLogrus(logger *logrus.Logger) Logger {
 	return newBarkLogrusLogger(logger)

logrus_logger_test.go

@@ -35,7 +35,7 @@ import (
 
 // Create a logrus logger that writes its out output to a buffer for inspection
 func getLogrusLogger() (*logrus.Logger, *bytes.Buffer) {
-	var logrusLogger *logrus.Logger = logrus.New()
+	logrusLogger := logrus.New()
 
 	buffer := &bytes.Buffer{}
 	logrusLogger.Out = buffer
@@ -155,10 +155,8 @@ func TestWithError(t *testing.T) {
 }
 
 func TestGetFields(t *testing.T) {
-	var logger bark.Logger
-
 	// Plain logger
-	logger = bark.NewLoggerFromLogrus(logrus.New())
+	logger := bark.NewLoggerFromLogrus(logrus.New())
 	require.Equal(t, logger.Fields(), bark.Fields(nil))
 
 	// Add nil, don't crash
@@ -286,3 +284,10 @@ func TestFatalf(t *testing.T) {
 	barkStderr := execFatalTool(t, "bark.Fatalf")
 	validateOutput(t, barkStderr, logrusStderr)
 }
+
+func TestNopLogger(t *testing.T) {
+	assert.NotPanics(t, func() {
+		logger := bark.NewNopLogger()
+		logger.Info("hello")
+	})
+}