Add default value for FeatureEnabledForID (#10)

lyft · Aug 15, 2017 · 320bd90 · 320bd90
1 parent 7e31e94
commit 320bd90
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Showing 4 changed files with 12 additions and 8 deletions.
diff --git a/snapshot/iface.go b/snapshot/iface.go
@@ -21,7 +21,9 @@ type IFace interface {
 	// the 0-100 value for the given feature. Use this method for "sticky" features
 	// @param key supplies the feature key to lookup.
 	// @param id supplies the ID to use in the CRC check.
-	FeatureEnabledForID(key string, id uint64) bool
+	// @param defaultValue supplies the default value that will be used if either the feature key
+	//        does not exist or it is not a bool.
+	FeatureEnabledForID(key string, id uint64, defaultValue bool) bool
 
 	// Fetch raw runtime data based on key.
 	// @param key supplies the key to fetch.

diff --git a/snapshot/nil.go b/snapshot/nil.go
@@ -15,6 +15,10 @@ func (n *Nil) FeatureEnabled(key string, defaultValue uint64) bool {
 	return defaultRandomGenerator.Random()%100 < min(defaultValue, 100)
 }
 
+func (n *Nil) FeatureEnabledForID(key string, id uint64, defaultValue bool) bool {
+	return defaultValue
+}
+
 func (n *Nil) Get(key string) string { return "" }
 
 func (n *Nil) GetInteger(key string, defaultValue uint64) uint64 {

diff --git a/snapshot/snapshot.go b/snapshot/snapshot.go
@@ -60,16 +60,14 @@ func (s *Snapshot) FeatureEnabled(key string, defaultValue uint64) bool {
 
 // FeatureEnabledForID checks that the crc32 of the id and key's byte value falls within the mod of
 // the 0-100 value for the given feature. Use this method for "sticky" features
-func (s *Snapshot) FeatureEnabledForID(key string, id uint64) bool {
+func (s *Snapshot) FeatureEnabledForID(key string, id uint64, defaultValue bool) bool {
 	if e, ok := s.Entries()[key]; ok {
 		if e.Uint64Valid {
 			return withinPercentile(id, uint32(e.Uint64Value), key)
 		}
-
-		return false
 	}
 
-	return false
+	return defaultValue
 }
 
 func (s *Snapshot) Get(key string) string {

diff --git a/snapshot/snapshot_test.go b/snapshot/snapshot_test.go
@@ -26,15 +26,15 @@ func TestSnapshot_FeatureEnabledForID(t *testing.T) {
 	key := "test"
 	ss := NewMock()
 	ss.SetUInt64(key, 100)
-	assert.True(t, ss.FeatureEnabledForID(key, 1))
+	assert.True(t, ss.FeatureEnabledForID(key, 1, true))
 
 	ss.SetUInt64(key, 0)
-	assert.False(t, ss.FeatureEnabledForID(key, 1))
+	assert.False(t, ss.FeatureEnabledForID(key, 1, true))
 
 	enabled := 0
 	for i := 1; i < 101; i++ {
 		ss.SetUInt64(key, uint64(i))
-		if ss.FeatureEnabledForID(key, uint64(i)) {
+		if ss.FeatureEnabledForID(key, uint64(i), true) {
 			enabled++
 		}
 	}