fix: overwrite object props in the same way as mount

[wattanx]

🔗 Linked issue

Fixes: #1072

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

In defu, the first argument takes precedence, so it is not overwritten.
With this fix, props can now be overwritten just like in mount.

[danielroe]

thank you! ❤️

[sebbayer]

@wattanx thank you very much for the quick fix, but I think that this solution still does not work for wrapper.setProps('propName', null) or setting that prop to undefined because of defu.

I would suggest a simple object merge instead of defu, like this:

return () => h(clonedComponent, { ...props, ...setProps, ...attrs }, slots)

[wattanx]

Isn't the use of wrapper.setProps('prop', null) not an intended use case in the first place?

[sebbayer]

The only source in the docs I could find was https://vuejs.org/guide/components/props.html#nullable-type

export default {
  props: {
    id: {
      type: [String, null],
      required: true
    }
  }
}

Also on the same page in section "Prop Validation" it says

export default {
  props: {
    // Basic type check
    //  (`null` and `undefined` values will allow any type)
    propA: Number,

And here's a comment by Evan You in the PR where null type was implemented: vuejs/core#3948 (comment)

So in my understanding null can be a possible value, but undefined sets the prop to its default value.

https://vuejs.org/guide/components/props.html#prop-validation

[wattanx]

@sebbayer

Isn't the use of wrapper.setProps('prop', null) not an intended use case in the first place?

What I mean is that, in @vue/test-utils, the setProps function does not accept a second argument.
https://stackblitz.com/edit/vitest-tests-browser-examples-yoyouz72

https://test-utils.vuejs.org/api/#setProps

setProps(props: Record<string, any>): Promise<void>

[sebbayer]

Sorry for the confusion, I meant wrapper.setProps({ propName: null }).