validation on negative time duration

gobreaker.go

@@ -86,11 +86,11 @@ func (c *Counts) clear() {
 //
 // Interval is the cyclic period of the closed state
 // for the CircuitBreaker to clear the internal Counts.
-// If Interval is 0, the CircuitBreaker doesn't clear internal Counts during the closed state.
+// If Interval is less than or equal to 0, the CircuitBreaker doesn't clear internal Counts during the closed state.
 //
 // Timeout is the period of the open state,
 // after which the state of the CircuitBreaker becomes half-open.
-// If Timeout is 0, the timeout value of the CircuitBreaker is set to 60 seconds.
+// If Timeout is less than or equal to 0, the timeout value of the CircuitBreaker is set to 60 seconds.
 //
 // ReadyToTrip is called with a copy of Counts whenever a request fails in the closed state.
 // If ReadyToTrip returns true, the CircuitBreaker will be placed into the open state.
@@ -135,7 +135,6 @@ func NewCircuitBreaker(st Settings) *CircuitBreaker {
 	cb := new(CircuitBreaker)
 
 	cb.name = st.Name
-	cb.interval = st.Interval
 	cb.onStateChange = st.OnStateChange
 
 	if st.MaxRequests == 0 {
@@ -144,7 +143,13 @@ func NewCircuitBreaker(st Settings) *CircuitBreaker {
 		cb.maxRequests = st.MaxRequests
 	}
 
-	if st.Timeout == 0 {
+	if st.Interval <= 0 {
+		cb.interval = defaultInterval
+	} else {
+		cb.interval = st.Interval
+	}
+
+	if st.Timeout <= 0 {
 		cb.timeout = defaultTimeout
 	} else {
 		cb.timeout = st.Timeout
@@ -168,6 +173,7 @@ func NewTwoStepCircuitBreaker(st Settings) *TwoStepCircuitBreaker {
 	}
 }
 
+const defaultInterval = time.Duration(0) * time.Second
 const defaultTimeout = time.Duration(60) * time.Second
 
 func defaultReadyToTrip(counts Counts) bool {

gobreaker_test.go

@@ -11,6 +11,7 @@ import (
 
 var defaultCB *CircuitBreaker
 var customCB *CircuitBreaker
+var negativeDurationCB *CircuitBreaker
 
 type StateChange struct {
 	name string
@@ -98,9 +99,19 @@ func newCustom() *CircuitBreaker {
 	return NewCircuitBreaker(customSt)
 }
 
+func newNegativeDurationCB() *CircuitBreaker {
+	var negativeSt Settings
+	negativeSt.Name = "ncb"
+	negativeSt.Interval = time.Duration(-30) * time.Second
+	negativeSt.Timeout = time.Duration(-90) * time.Second
+
+	return NewCircuitBreaker(negativeSt)
+}
+
 func init() {
 	defaultCB = NewCircuitBreaker(Settings{})
 	customCB = newCustom()
+	negativeDurationCB = newNegativeDurationCB()
 }
 
 func TestStateConstants(t *testing.T) {
@@ -136,6 +147,17 @@ func TestNewCircuitBreaker(t *testing.T) {
 	assert.Equal(t, StateClosed, customCB.state)
 	assert.Equal(t, Counts{0, 0, 0, 0, 0}, customCB.counts)
 	assert.False(t, customCB.expiry.IsZero())
+
+	negativeDurationCB := newNegativeDurationCB()
+	assert.Equal(t, "ncb", negativeDurationCB.name)
+	assert.Equal(t, uint32(1), negativeDurationCB.maxRequests)
+	assert.Equal(t, time.Duration(0)*time.Second, negativeDurationCB.interval)
+	assert.Equal(t, time.Duration(60)*time.Second, negativeDurationCB.timeout)
+	assert.NotNil(t, negativeDurationCB.readyToTrip)
+	assert.Nil(t, negativeDurationCB.onStateChange)
+	assert.Equal(t, StateClosed, negativeDurationCB.state)
+	assert.Equal(t, Counts{0, 0, 0, 0, 0}, negativeDurationCB.counts)
+	assert.True(t, negativeDurationCB.expiry.IsZero())
 }
 
 func TestDefaultCircuitBreaker(t *testing.T) {