Allow assign all attributes as props

active-rfcs/0000-no-props-component.md

@@ -0,0 +1,95 @@
+- Start Date: 2021-03-12
+- Target Major Version: 3.x
+- Reference Issues: None
+- Implementation PR: None
+
+# Summary
+
+Allow defining props by Typescript interface
+
+# Basic example
+
+```ts
+import { defineComponent } from 'vue'
+
+interface CompProps {
+  name: string
+  age: number
+}
+
+// VCA
+defineComponent<CompProps>(
+  noProps: true,
+  setup(props) {
+    props.name // string
+    props.age // number
+  }
+)
+
+// VOA
+defineComponent<CompProps>({
+  noProps: true,
+  mounted(){
+    this.name // string
+    this.age // number
+  }
+})
+
+
+// No typescript
+// in this case `vm` will have a `Record<string, any>` to allow usage of any prop
+defineComponent({
+  noProps: true,
+  mounted(){
+    this.name // no typing
+  }
+})
+```
+
+# Motivation
+
+People coming form other frameworks (ReactJS) are used to pass `Props` interface as a first generic and expecting to "be working" when using `props`. That's not possible because `vue` has runtime checks and the props will be inferred by the `props` object.
+Other case could be: No need to have runtime validation.
+
+# Detailed design
+
+In `vue` everything declared in the `props` object will be bound to the component instance, allowing the direct access in the template (without `$props.` prefix), everything else will be added to `$attrs` object.
+
+When passing the first generic to `defineComponent` (eg: `defineComponent<{ title: string }>`), is expected that will be `props` and have the same behaviour, but in reality that is not possible since what drives the assigning to `$props`/`$attrs` is if that `prop` name is defined in `props` object.
+
+To achieve what's proposed in this RFC, attributes will need to be treated as props, for that to happen we need an extra option (eg: `noProps: true`) or passing `props:null`.
+
+If `noProps: true`:
+
+- Will have implicitly `inheritAttrs:false`.
+- `$attrs` will be bound to the `vm` (just like props are)
+- `class` and `style` will not be bound to the `vm` since they will be treated as native and allowed to fallthrough.
+- `props` cannot be declared with using `noProps:true`
+- If a attribute has the same name as a local property (`computed`, `data`, `methods`, etc), it should warn and do not update or override the local property, that attribute should be added on the `$attrs` or `$props` object
+
+# Drawbacks
+
+- Having an extra `prop` on the options might be a bit confusing
+- Having the implicit `inheritAttrs:false` might cause some confusing to more experienced users
+- Having `$attrs` bound to the `vm` might cause some unwanted behaviour.
+- Increased complexity on the `defineComponent` by having one more way to do handle the props from generic type.
+
+# Alternatives
+
+```ts
+defineComponent({
+  props: null,
+})
+// or
+defineComponent({
+  props: false,
+})
+```
+
+# Adoption strategy
+
+This is completely optional.
+
+# Unresolved questions
+
+There might be some unforeseen behaviour by bounding `$attrs` to the `vm`