Pr53 with unit tests (#54)

* SetConfigThreadSafe should set notThreadSafeConfig to new config first

Change-Id: Ib8cde17faa1054e511d64ad23199ef519dc7e307

* Add unit test for setting circuit config

* Expand config unit test

Check the before and after state to make sure it changed

circuit.go

@@ -71,9 +71,8 @@ func (c *Circuit) ConcurrentFallbacks() int64 {
 func (c *Circuit) SetConfigThreadSafe(config Config) {
 	c.notThreadSafeConfigMu.Lock()
 	defer c.notThreadSafeConfigMu.Unlock()
-	//c.circuitStats.SetConfigThreadSafe(config)
-	c.threadSafeConfig.reset(c.notThreadSafeConfig)
 	c.notThreadSafeConfig = config
+	c.threadSafeConfig.reset(c.notThreadSafeConfig)
 	if cfg, ok := c.OpenToClose.(Configurable); ok {
 		cfg.SetConfigThreadSafe(config)
 	}

circuit_test.go

@@ -345,6 +345,22 @@ func TestFailingFallbackCircuit(t *testing.T) {
 	}
 }
 
+func TestSetConfigThreadSafe(t *testing.T) {
+	var breaker Circuit
+
+	if breaker.threadSafeConfig.CircuitBreaker.Disabled.Get() {
+		t.Error("Circuit should start off not disabled")
+	}
+	breaker.SetConfigThreadSafe(Config{
+		General: GeneralConfig{
+			Disabled: true,
+		},
+	})
+	if !breaker.threadSafeConfig.CircuitBreaker.Disabled.Get() {
+		t.Error("Circuit should be disabled after setting config to disabled")
+	}
+}
+
 //func TestSLO(t *testing.T) {
 //	c := NewCircuitFromConfig("TestFailingCircuit", Config{
 //		GoSpecific: GoSpecificConfig{