add test recovery (#1004)

* add middle/validate test

* add middle/recovery test

middleware/recovery/recovery_test.go

@@ -0,0 +1,21 @@
+package recovery
+
+import (
+	"context"
+	"testing"
+)
+
+func TestOnce(t *testing.T) {
+	defer func() {
+		if recover() != nil {
+			t.Error("fail")
+		}
+	}()
+
+	next := func(ctx context.Context, req interface{}) (interface{}, error) {
+		panic("panic reason")
+	}
+	next = Recovery()(next)
+	_, e := next(context.Background(), "panic")
+	t.Logf("succ and reason is %v", e)
+}