Conside if the level is to be used separately from if the levels should be calculated (#137)

* Conside if the level is to be used separately from if the levels should be calculated

* Add a test for post-SetLevel .Named()


---------

Co-authored-by: Mike Palmiotto <mike.palmiotto@hashicorp.com>

Author: Evan Phoenix

intlogger.go

@@ -93,6 +93,9 @@ type intLogger struct {
 	writer *writer
 	level  *int32
 
+	// The value of curEpoch when our level was set
+	setEpoch uint64
+
 	// The value of curEpoch the last time we performed the level sync process
 	ownEpoch uint64
 
@@ -892,18 +895,19 @@ func (l *intLogger) SetLevel(level Level) {
 	l.level = nsl
 
 	l.ownEpoch = atomic.AddUint64(l.curEpoch, 1)
+	l.setEpoch = l.ownEpoch
 }
 
 func (l *intLogger) searchLevelPtr() *int32 {
 	p := l.parent
 
 	ptr := l.level
 
-	max := l.ownEpoch
+	max := l.setEpoch
 
 	for p != nil {
-		if p.ownEpoch > max {
-			max = p.ownEpoch
+		if p.setEpoch > max {
+			max = p.setEpoch
 			ptr = p.level
 		}
 

logger_test.go

@@ -666,7 +666,44 @@ func TestLogger(t *testing.T) {
 		assert.Equal(t, Error, b.GetLevel())
 	})
 
-	t.Run("level sync example", func(t *testing.T) {
+	t.Run("level sync example 1", func(t *testing.T) {
+		var buf bytes.Buffer
+
+		logger := New(&LoggerOptions{
+			Name:            "root",
+			Output:          &buf,
+			SyncParentLevel: true,
+		})
+
+		s := assert.New(t)
+
+		a := logger.Named("a")
+		b := a.Named("b")
+		c := a.Named("c")
+
+		b.SetLevel(Warn)
+		s.Equal(Info, a.GetLevel())
+		s.Equal(Warn, b.GetLevel())
+		s.Equal(Info, c.GetLevel())
+
+		c.SetLevel(Error)
+		s.Equal(Info, a.GetLevel())
+		s.Equal(Warn, b.GetLevel())
+		s.Equal(Error, c.GetLevel())
+
+		a.SetLevel(Warn)
+		s.Equal(Warn, a.GetLevel())
+		s.Equal(Warn, b.GetLevel())
+		s.Equal(Warn, c.GetLevel())
+
+		logger.SetLevel(Trace)
+		s.Equal(Trace, logger.GetLevel())
+		s.Equal(Trace, a.GetLevel())
+		s.Equal(Trace, b.GetLevel())
+		s.Equal(Trace, c.GetLevel())
+	})
+
+	t.Run("level sync example 2", func(t *testing.T) {
 		var buf bytes.Buffer
 
 		logger := New(&LoggerOptions{
@@ -700,6 +737,40 @@ func TestLogger(t *testing.T) {
 		s.Equal(Trace, b.GetLevel())
 		s.Equal(Trace, c.GetLevel())
 	})
+	t.Run("level sync example 3", func(t *testing.T) {
+		var buf bytes.Buffer
+
+		logger := New(&LoggerOptions{
+			Name:            "root",
+			Output:          &buf,
+			SyncParentLevel: true,
+		})
+
+		s := assert.New(t)
+
+		a := logger.Named("a")
+		b := a.Named("b")
+
+		a.SetLevel(Trace)
+		s.Equal(Trace, a.GetLevel())
+		s.Equal(Trace, b.GetLevel())
+
+		b.SetLevel(Warn)
+		s.Equal(Trace, a.GetLevel())
+		s.Equal(Warn, b.GetLevel())
+
+		c := a.Named("c")
+
+		c.SetLevel(Error)
+		s.Equal(Trace, a.GetLevel())
+		s.Equal(Warn, b.GetLevel())
+		s.Equal(Error, c.GetLevel())
+
+		a.SetLevel(Warn)
+		s.Equal(Warn, a.GetLevel())
+		s.Equal(Warn, b.GetLevel())
+		s.Equal(Warn, c.GetLevel())
+	})
 }
 
 func TestLogger_leveledWriter(t *testing.T) {