fix(core): Add warning message if prop type=null and value=null

[jamesnakagawa]

Description

Adds a warning when the prop's type=null and the value is also null or undefined.

Motivation

defineProps will generate type=null if the static type cannot be compiled into a basic type. However, this also means null values will be allowed even though the prop is required.

See a live demo of the bug here

[github-actions]

Size Report

Bundles

File	Size	Gzip	Brotli
runtime-dom.global.prod.js	100 kB	37.9 kB	34.2 kB
vue.global.prod.js	158 kB	57.8 kB	51.4 kB

Usages

Name	Size	Gzip	Brotli
createApp (CAPI only)	46.6 kB	18.3 kB	16.7 kB
createApp	54.6 kB	21.3 kB	19.4 kB
createSSRApp	58.7 kB	23 kB	20.9 kB
defineCustomElement	59.4 kB	22.8 kB	20.8 kB
overall	68.4 kB	26.4 kB	24 kB

[pkg-pr-new]

Open in Stackblitz

@vue/compiler-core

npm i https://pkg.pr.new/@vue/compiler-core@12571

@vue/compiler-dom

npm i https://pkg.pr.new/@vue/compiler-dom@12571

@vue/compiler-ssr

npm i https://pkg.pr.new/@vue/compiler-ssr@12571

@vue/compiler-sfc

npm i https://pkg.pr.new/@vue/compiler-sfc@12571

@vue/reactivity

npm i https://pkg.pr.new/@vue/reactivity@12571

@vue/runtime-core

npm i https://pkg.pr.new/@vue/runtime-core@12571

@vue/runtime-dom

npm i https://pkg.pr.new/@vue/runtime-dom@12571

@vue/server-renderer

npm i https://pkg.pr.new/@vue/server-renderer@12571

@vue/shared

npm i https://pkg.pr.new/@vue/shared@12571

vue

npm i https://pkg.pr.new/vue@12571

@vue/compat

npm i https://pkg.pr.new/@vue/compat@12571

commit: 5d65b1e