Merge pull request #44 from InVisionApp/emptyok

Do not error on empty check config list

health.go

@@ -153,10 +153,6 @@ func (h *Health) AddChecks(cfgs []*Config) error {
 		return ErrNoAddCfgWhenActive
 	}
 
-	if len(cfgs) == 0 {
-		return ErrEmptyConfigs
-	}
-
 	h.configs = append(h.configs, cfgs...)
 
 	return nil
@@ -180,6 +176,11 @@ func (h *Health) Start() error {
 		return ErrAlreadyRunning
 	}
 
+	// if there are no check configs, this is a noop
+	if len(h.configs) < 1 {
+		return nil
+	}
+
 	for _, c := range h.configs {
 		h.Logger.WithFields(log.Fields{"name": c.Name}).Debug("Starting checker")
 		ticker := time.NewTicker(c.Interval)

health_test.go

@@ -77,12 +77,11 @@ func TestAddChecks(t *testing.T) {
 		Expect(err).To(Equal(ErrNoAddCfgWhenActive))
 	})
 
-	t.Run("Should error if passed in empty config slice", func(t *testing.T) {
+	t.Run("Should not error if passed in empty config slice", func(t *testing.T) {
 		h := setupNewTestHealth()
 		err := h.AddChecks([]*Config{})
 
-		Expect(err).To(HaveOccurred())
-		Expect(err).To(Equal(ErrEmptyConfigs))
+		Expect(err).ToNot(HaveOccurred())
 	})
 }
 
@@ -420,6 +419,17 @@ func TestStartRunner(t *testing.T) {
 		Expect(h.failed.val()).To(BeFalse())
 	})
 
+	t.Run("Happy path - no checkers is noop", func(t *testing.T) {
+		h := New()
+
+		Expect(h).ToNot(BeNil())
+
+		err := h.Start()
+		Expect(err).ToNot(HaveOccurred())
+
+		Expect(h.active.val()).To(BeFalse())
+	})
+
 	t.Run("Happy path - 1 checker fails (non-fatal)", func(t *testing.T) {
 		checker1 := &fakes.FakeICheckable{}
 		checker2 := &fakes.FakeICheckable{}