workflow: add size-check package

package.json

@@ -6,7 +6,7 @@
   "scripts": {
     "dev": "node scripts/dev.js",
     "build": "node scripts/build.js",
-    "size-runtime": "node scripts/build.js runtime-dom -p -f global",
+    "size-runtime": "node scripts/build.js runtime-dom size-check -p -f global",
     "size-compiler": "node scripts/build.js compiler-dom -p -f global",
     "size": "yarn size-runtime && yarn size-compiler",
     "lint": "prettier --write --parser typescript \"packages/**/*.ts?(x)\"",

packages/size-check/README.md

@@ -0,0 +1,3 @@
+# Size Check
+
+This package is private and is used for checking the baseline runtime size after tree-shaking (with only the bare minimal code required to render something to the screen).

packages/size-check/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "@vue/size-check",
+  "version": "3.0.0-alpha.1",
+  "private": true,
+  "buildOptions": {
+    "name": "Vue",
+    "formats": ["global"]
+  }
+}

packages/size-check/src/index.ts

@@ -0,0 +1,4 @@
+import { render, createVNode } from '@vue/runtime-dom'
+
+// The bare minimum code required for rendering something to the screen
+render(createVNode('div'), document.getElementById('app')!)