feat(compiler-core): support v-is

see https://github.com/vuejs/rfcs/pull/149 for details

packages/compiler-core/__tests__/parse.spec.ts

@@ -646,6 +646,55 @@ describe('compiler: parse', () => {
       })
     })
 
+    test('v-is without `isNativeTag`', () => {
+      const ast = baseParse(
+        `<div></div><div v-is="'foo'"></div><Comp></Comp>`,
+        {
+          isNativeTag: tag => tag === 'div'
+        }
+      )
+
+      expect(ast.children[0]).toMatchObject({
+        type: NodeTypes.ELEMENT,
+        tag: 'div',
+        tagType: ElementTypes.ELEMENT
+      })
+
+      expect(ast.children[1]).toMatchObject({
+        type: NodeTypes.ELEMENT,
+        tag: 'div',
+        tagType: ElementTypes.COMPONENT
+      })
+
+      expect(ast.children[2]).toMatchObject({
+        type: NodeTypes.ELEMENT,
+        tag: 'Comp',
+        tagType: ElementTypes.COMPONENT
+      })
+    })
+
+    test('v-is with `isNativeTag`', () => {
+      const ast = baseParse(`<div></div><div v-is="'foo'"></div><Comp></Comp>`)
+
+      expect(ast.children[0]).toMatchObject({
+        type: NodeTypes.ELEMENT,
+        tag: 'div',
+        tagType: ElementTypes.ELEMENT
+      })
+
+      expect(ast.children[1]).toMatchObject({
+        type: NodeTypes.ELEMENT,
+        tag: 'div',
+        tagType: ElementTypes.COMPONENT
+      })
+
+      expect(ast.children[2]).toMatchObject({
+        type: NodeTypes.ELEMENT,
+        tag: 'Comp',
+        tagType: ElementTypes.COMPONENT
+      })
+    })
+
     test('custom element', () => {
       const ast = baseParse('<div></div><comp></comp>', {
         isNativeTag: tag => tag === 'div',

packages/compiler-core/__tests__/transforms/transformElement.spec.ts

@@ -829,6 +829,25 @@ describe('compiler: element transform', () => {
         }
       })
     })
+
+    test('v-is', () => {
+      const { node, root } = parseWithBind(`<div v-is="'foo'" />`)
+      expect(root.helpers).toContain(RESOLVE_DYNAMIC_COMPONENT)
+      expect(node).toMatchObject({
+        tag: {
+          callee: RESOLVE_DYNAMIC_COMPONENT,
+          arguments: [
+            {
+              type: NodeTypes.SIMPLE_EXPRESSION,
+              content: `'foo'`,
+              isStatic: false
+            }
+          ]
+        },
+        // should skip v-is runtime check
+        directives: undefined
+      })
+    })
   })
 
   test('<svg> should be forced into blocks', () => {