cancel trait side effect

packages/runtime/src/App.tsx

@@ -126,12 +126,24 @@ export const ImplWrapper = React.forwardRef<
   }, [c.traits]);
 
   // reduce traitResults
-  const propsFromTraits: TraitResult = useMemo(() => {
+  const propsFromTraits: TraitResult['props'] = useMemo(() => {
     return Array.from(traitResults.values()).reduce(
       (prevProps, result: TraitResult) => {
-        return { ...prevProps, ...result.props };
+        if (!result.props) {
+          return prevProps;
+        }
+
+        let effects = prevProps?.effects || [];
+        if (result.props?.effects) {
+          effects = effects?.concat(result.props?.effects);
+        }
+        return {
+          ...prevProps,
+          ...result.props,
+          effects,
+        };
       },
-      { props: null }
+      {} as TraitResult['props']
     );
   }, [traitResults]);
 

packages/runtime/src/components/core/Dummy.tsx

@@ -1,9 +1,16 @@
 import { createComponent } from '@meta-ui/core';
+import { useEffect } from 'react';
+import { ComponentImplementation } from 'src/registry';
+
+const Dummy: ComponentImplementation<Record<string, unknown>> = ({
+  effects,
+}) => {
+  useEffect(() => {
+    effects?.forEach(e => e());
+  }, []);
 
-const Dummy = () => {
   return null;
 };
-
 export default {
   ...createComponent({
     version: 'core/v1',

packages/runtime/src/registry.tsx

@@ -72,6 +72,7 @@ export type ComponentMergedProps = {
   style?: Record<string, any>;
   data?: Record<string, unknown>;
   callbackMap?: CallbackMap;
+  effects?: Array<() => void>;
   app?: RuntimeApplication;
 };
 
@@ -84,6 +85,7 @@ export type TraitResult = {
     data?: unknown;
     style?: Record<string, any>;
     callbackMap?: CallbackMap;
+    effects?: Array<() => void>;
   } | null;
 };
 

packages/runtime/src/traits/core/fetch.tsx

@@ -97,7 +97,13 @@ const useFetchTrait: TraitImplementation<Static<typeof PropsSchema>> = ({
   });
 
   return {
-    props: null,
+    props: {
+      effects: [
+        () => {
+          hasFetchedMap.set(hashId, false);
+        },
+      ],
+    },
   };
 };