linting: add to Makefile & do some fixes

log/filter_test.go

@@ -73,8 +73,7 @@ func TestVariousLevels(t *testing.T) {
 func TestLevelContext(t *testing.T) {
 	var buf bytes.Buffer
 
-	var logger log.Logger
-	logger = log.NewTMJSONLogger(&buf)
+	logger := log.NewTMJSONLogger(&buf)
 	logger = log.NewFilter(logger, log.AllowError())
 	logger = logger.With("context", "value")
 
@@ -93,8 +92,7 @@ func TestLevelContext(t *testing.T) {
 func TestVariousAllowWith(t *testing.T) {
 	var buf bytes.Buffer
 
-	var logger log.Logger
-	logger = log.NewTMJSONLogger(&buf)
+	logger := log.NewTMJSONLogger(&buf)
 
 	logger1 := log.NewFilter(logger, log.AllowError(), log.AllowInfoWith("context", "value"))
 	logger1.With("context", "value").Info("foo", "bar", "baz")

log/tmfmt_logger.go

@@ -49,9 +49,10 @@ func (l tmfmtLogger) Log(keyvals ...interface{}) error {
 	enc.Reset()
 	defer tmfmtEncoderPool.Put(enc)
 
+	const unknown = "unknown"
 	lvl := "none"
-	msg := "unknown"
-	module := "unknown"
+	msg := unknown
+	module := unknown
 
 	// indexes of keys to skip while encoding later
 	excludeIndexes := make([]int, 0)
@@ -90,7 +91,7 @@ func (l tmfmtLogger) Log(keyvals ...interface{}) error {
 	//     Stopping ...					- message
 	enc.buf.WriteString(fmt.Sprintf("%c[%s] %-44s ", lvl[0]-32, time.Now().UTC().Format("01-02|15:04:05.000"), msg))
 
-	if module != "unknown" {
+	if module != unknown {
 		enc.buf.WriteString("module=" + module + " ")
 	}
 

log/tracing_logger_test.go

@@ -14,8 +14,7 @@ import (
 func TestTracingLogger(t *testing.T) {
 	var buf bytes.Buffer
 
-	var logger log.Logger
-	logger = log.NewTMJSONLogger(&buf)
+	logger := log.NewTMJSONLogger(&buf)
 
 	logger1 := log.NewTracingLogger(logger)
 	err1 := errors.New("Courage is grace under pressure.")