[BUG] setup doesn't support return object with type of Module

[xialvjun]

The bug( or maybe not bug) code is at

composition-api/src/mixin.ts

Line 118 in a43090d

} else if (isPlainObject(binding)) {

Sorry I can not offer an codesandbox or stackblitz link, because this bug is related to the building enviroment.

My local build enviroment is: vite + vite-plugin-vue2;

The build script is just "build": "vite build", without tsc && because esbuild support typescript.

Then with code:

App.vue

<template><div @click="a++">{{a}}</div></template>
<script lang="ts">
import { defineComponent } from "@vue/composition-api"
import * as refs from "./refs"; // refs is just a ts file with some global ref state.

export default defineComponent({
  setup() {
    return { ...refs }; // refs is of type "[object Module]", and `{ ...refs }` is also of type "[object Module]", so isPlainObject return false.
    // I need to convert it to
    const spread = obj => Object.keys(obj).reduce((acc, cv) => ({...acc, [cv]: obj[cv]}), {});
    return { ...(spread(refs)) }; // then it works.
  }
});
</script>

refs.ts

import {} from '@vue/composition-api';
export const a = ref(0);
export const b = ref('');

[MinatoHikari]

You should not directly export const something = ref()

export const useRef = () => {
    const a = ref()

    return { a }
}

[LinusBorg]

@MinatoHikari exporting a ref like OP does is totally fine.

[xialvjun]

I don't have a need to SSR, so I just export a global ref.

[xialvjun]

I think changing isPlainObject to isObject which is val => val !== null && typeof val === 'object' is enough. Vue3 is just like this https://github.com/vuejs/vue-next/blob/87c86e4cc2/packages/runtime-core/src/component.ts#L688