Fix: make selector `react immediately`

adapters/outboundgroup/selector.go

@@ -59,6 +59,7 @@ func (s *Selector) Set(name string) error {
 	for _, proxy := range getProvidersProxies(s.providers) {
 		if proxy.Name() == name {
 			s.selected = name
+			s.single.Reset()
 			return nil
 		}
 	}

common/singledo/singledo.go

@@ -50,6 +50,10 @@ func (s *Single) Do(fn func() (interface{}, error)) (v interface{}, err error, s
 	return call.val, call.err, false
 }
 
+func (s *Single) Reset() {
+	s.last = time.Time{}
+}
+
 func NewSingle(wait time.Duration) *Single {
 	return &Single{wait: wait}
 }

common/singledo/singledo_test.go

@@ -19,7 +19,7 @@ func TestBasic(t *testing.T) {
 	}
 
 	var wg sync.WaitGroup
-	const n = 10
+	const n = 5
 	wg.Add(n)
 	for i := 0; i < n; i++ {
 		go func() {
@@ -33,7 +33,7 @@ func TestBasic(t *testing.T) {
 
 	wg.Wait()
 	assert.Equal(t, 1, foo)
-	assert.Equal(t, 9, shardCount)
+	assert.Equal(t, 4, shardCount)
 }
 
 func TestTimer(t *testing.T) {
@@ -51,3 +51,18 @@ func TestTimer(t *testing.T) {
 	assert.Equal(t, 1, foo)
 	assert.True(t, shard)
 }
+
+func TestReset(t *testing.T) {
+	single := NewSingle(time.Millisecond * 30)
+	foo := 0
+	call := func() (interface{}, error) {
+		foo++
+		return nil, nil
+	}
+
+	single.Do(call)
+	single.Reset()
+	single.Do(call)
+
+	assert.Equal(t, 2, foo)
+}