VuReact is a compiler toolchain for migrating from Vue to React — and for writing React with Vue 3 syntax.
In this article, we will look at how Vue 3's defineExpose() macro is mapped into React.
Before We Start
To keep the examples easy to read, this article follows two simple conventions:
- All Vue and React snippets focus on core logic only, with full component wrappers and unrelated configuration omitted.
- The discussion assumes you are already familiar with the API shape and core behavior of Vue 3
defineExpose().
Compilation Mapping
Vue defineExpose() -> React forwardRef() + useImperativeHandle()
defineExpose() is the macro used inside Vue 3 <script setup> to expose internal state or methods from a child component to its parent.
VuReact compiles that pattern into React's forwardRef() plus useImperativeHandle(), allowing the parent component to access the exposed object through a ref.
- Vue
<script setup lang="ts">
import { ref, defineExpose } from 'vue';
defineProps<{ title: string }>();
const count = ref(0);
const increment = () => count.value++;
defineExpose({
count,
increment,
});
</script>
- Compiled React
import { forwardRef, useCallback, useImperativeHandle, memo } from 'react';
import { useVRef } from '@vureact/runtime-core';
type IComponentProps = { title: string };
const Component = memo(
forwardRef<any, IComponentProps>((props, expose) => {
const count = useVRef(0);
const increment = useCallback(() => {
count.value++;
}, [count.value]);
useImperativeHandle(expose, () => ({
count,
increment,
}));
return <div>{count.value}</div>;
}),
);
export default Component;
As the example shows, Vue defineExpose() is compiled into React's forwardRef() and useImperativeHandle() combination.
VuReact preserves the structure of the exposed object, and exposed refs still use .value, which keeps the interaction model close to Vue.
Parent access: Vue ref + expose -> React ref.current
In Vue, parent components access exposed child values through ref and expose. In React, VuReact maps that pattern to useRef() plus ref.current.
- Vue parent
<template>
<Component ref="childRef" />
</template>
<script setup lang="ts">
import { onMounted, ref } from 'vue';
const childRef = ref();
onMounted(() => {
childRef.value?.count.value; // 0
childRef.value?.increment();
childRef.value?.count.value; // 1
});
</script>
- Compiled React parent
const Parent = () => {
const childRef = useRef();
useMounted(() => {
childRef.current?.count.value; // 0
childRef.current?.increment();
childRef.current?.count.value; // 1
});
return <Component ref={childRef} />;
};
VuReact keeps the parent access path aligned with the original Vue intent, so exposed child refs and methods remain straightforward to use.