test: update fragment tests

packages/runtime-core/__tests__/vdomAttrsFallthrough.spec.ts

@@ -1,6 +1,6 @@
 // using DOM renderer because this case is mostly DOM-specific
 import {
-  createVNode as h,
+  h,
   render,
   nextTick,
   mergeProps,

packages/runtime-core/__tests__/vdomFragment.spec.ts

@@ -1,201 +1,295 @@
-// These tests are outdated.
-
-// import {
-//   createVNode as h,
-//   render,
-//   nodeOps,
-//   NodeTypes,
-//   TestElement,
-//   Fragment,
-//   reactive,
-//   serialize,
-//   nextTick,
-//   resetOps,
-//   dumpOps,
-//   NodeOpTypes
-// } from '@vue/runtime-test'
-
-// describe('vdom: fragment', () => {
-//   it('should allow returning multiple component root nodes', async () => {
-//     class App extends Component {
-//       render() {
-//         return [h('div', 'one'), 'two']
-//       }
-//     }
-//     const root = nodeOps.createElement('div')
-//     await render(h(App), root)
-//     expect(serialize(root)).toBe(`<div><div>one</div>two</div>`)
-//     expect(root.children.length).toBe(2)
-//     expect(root.children[0]).toMatchObject({
-//       type: NodeTypes.ELEMENT,
-//       tag: 'div'
-//     })
-//     expect((root.children[0] as TestElement).children[0]).toMatchObject({
-//       type: NodeTypes.TEXT,
-//       text: 'one'
-//     })
-//     expect(root.children[1]).toMatchObject({
-//       type: NodeTypes.TEXT,
-//       text: 'two'
-//     })
-//   })
-
-//   it('should be able to explicitly create fragments', async () => {
-//     class App extends Component {
-//       render() {
-//         return h('div', [h(Fragment, [h('div', 'one'), 'two'])])
-//       }
-//     }
-//     const root = nodeOps.createElement('div')
-//     await render(h(App), root)
-//     const parent = root.children[0] as TestElement
-//     expect(serialize(parent)).toBe(`<div><div>one</div>two</div>`)
-//   })
-
-//   it('should be able to patch fragment children (unkeyed)', async () => {
-//     const state = observable({ ok: true })
-//     class App extends Component {
-//       render() {
-//         return state.ok
-//           ? createFragment(
-//               [h('div', 'one'), createTextVNode('two')],
-//               ChildrenFlags.NONE_KEYED_VNODES
-//             )
-//           : createFragment(
-//               [h('div', 'foo'), createTextVNode('bar'), createTextVNode('baz')],
-//               ChildrenFlags.NONE_KEYED_VNODES
-//             )
-//       }
-//     }
-//     const root = nodeOps.createElement('div')
-//     await render(h(App), root)
-
-//     expect(serialize(root)).toBe(`<div><div>one</div>two</div>`)
-
-//     state.ok = false
-//     await nextTick()
-//     expect(serialize(root)).toBe(`<div><div>foo</div>barbaz</div>`)
-//   })
-
-//   it('should be able to patch fragment children (implicitly keyed)', async () => {
-//     const state = observable({ ok: true })
-//     class App extends Component {
-//       render() {
-//         return state.ok
-//           ? [h('div', 'one'), 'two']
-//           : [h('pre', 'foo'), 'bar', 'baz']
-//       }
-//     }
-//     const root = nodeOps.createElement('div')
-//     await await render(h(App), root)
-
-//     expect(serialize(root)).toBe(`<div><div>one</div>two</div>`)
-
-//     state.ok = false
-//     await nextTick()
-//     expect(serialize(root)).toBe(`<div><pre>foo</pre>barbaz</div>`)
-//   })
-
-//   it('should be able to patch fragment children (explcitly keyed)', async () => {
-//     const state = observable({ ok: true })
-//     class App extends Component {
-//       render() {
-//         return state.ok
-//           ? [h('div', { key: 1 }, 'one'), h('div', { key: 2 }, 'two')]
-//           : [h('div', { key: 2 }, 'two'), h('div', { key: 1 }, 'one')]
-//       }
-//     }
-//     const root = nodeOps.createElement('div')
-//     await render(h(App), root)
-
-//     expect(serialize(root)).toBe(`<div><div>one</div><div>two</div></div>`)
-
-//     resetOps()
-//     state.ok = false
-//     await nextTick()
-//     expect(serialize(root)).toBe(`<div><div>two</div><div>one</div></div>`)
-//     const ops = dumpOps()
-//     // should be moving nodes instead of re-creating them
-//     expect(ops.some(op => op.type === NodeOpTypes.CREATE)).toBe(false)
-//   })
-
-//   it('should be able to move fragment', async () => {
-//     const state = observable({ ok: true })
-//     class App extends Component {
-//       render() {
-//         return state.ok
-//           ? h('div', [
-//               h('div', { key: 1 }, 'outer'),
-//               h(Fragment, { key: 2 }, [
-//                 h('div', { key: 1 }, 'one'),
-//                 h('div', { key: 2 }, 'two')
-//               ])
-//             ])
-//           : h('div', [
-//               h(Fragment, { key: 2 }, [
-//                 h('div', { key: 2 }, 'two'),
-//                 h('div', { key: 1 }, 'one')
-//               ]),
-//               h('div', { key: 1 }, 'outer')
-//             ])
-//       }
-//     }
-//     const root = nodeOps.createElement('div')
-//     await render(h(App), root)
-//     const parent = root.children[0] as TestElement
-
-//     expect(serialize(parent)).toBe(
-//       `<div><div>outer</div><div>one</div><div>two</div></div>`
-//     )
-
-//     resetOps()
-//     state.ok = false
-//     await nextTick()
-//     expect(serialize(parent)).toBe(
-//       `<div><div>two</div><div>one</div><div>outer</div></div>`
-//     )
-//     const ops = dumpOps()
-//     // should be moving nodes instead of re-creating them
-//     expect(ops.some(op => op.type === NodeOpTypes.CREATE)).toBe(false)
-//   })
-
-//   it('should be able to handle nested fragments', async () => {
-//     const state = observable({ ok: true })
-//     class App extends Component {
-//       render() {
-//         return state.ok
-//           ? [
-//               h('div', { key: 1 }, 'outer'),
-//               h(Fragment, { key: 2 }, [
-//                 h('div', { key: 1 }, 'one'),
-//                 h('div', { key: 2 }, 'two')
-//               ])
-//             ]
-//           : [
-//               h(Fragment, { key: 2 }, [
-//                 h('div', { key: 2 }, 'two'),
-//                 h('div', { key: 1 }, 'one')
-//               ]),
-//               h('div', { key: 1 }, 'outer')
-//             ]
-//       }
-//     }
-
-//     const root = nodeOps.createElement('div')
-//     await render(h(App), root)
-
-//     expect(serialize(root)).toBe(
-//       `<div><div>outer</div><div>one</div><div>two</div></div>`
-//     )
-
-//     resetOps()
-//     state.ok = false
-//     await nextTick()
-//     expect(serialize(root)).toBe(
-//       `<div><div>two</div><div>one</div><div>outer</div></div>`
-//     )
-//     const ops = dumpOps()
-//     // should be moving nodes instead of re-creating them
-//     expect(ops.some(op => op.type === NodeOpTypes.CREATE)).toBe(false)
-//   })
-// })
+import {
+  h,
+  createVNode,
+  render,
+  nodeOps,
+  NodeTypes,
+  TestElement,
+  serialize,
+  Fragment,
+  reactive,
+  nextTick,
+  PatchFlags,
+  resetOps,
+  dumpOps,
+  NodeOpTypes
+} from '@vue/runtime-test'
+
+describe('vdom: fragment', () => {
+  it('should allow returning multiple component root nodes', () => {
+    const App = {
+      render() {
+        return [h('div', 'one'), 'two']
+      }
+    }
+
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+
+    expect(serialize(root)).toBe(`<div><!----><div>one</div>two<!----></div>`)
+    expect(root.children.length).toBe(4)
+    expect(root.children[0]).toMatchObject({
+      type: NodeTypes.COMMENT
+    })
+    expect(root.children[1]).toMatchObject({
+      type: NodeTypes.ELEMENT,
+      tag: 'div'
+    })
+    expect((root.children[1] as TestElement).children[0]).toMatchObject({
+      type: NodeTypes.TEXT,
+      text: 'one'
+    })
+    expect(root.children[2]).toMatchObject({
+      type: NodeTypes.TEXT,
+      text: 'two'
+    })
+    expect(root.children[3]).toMatchObject({
+      type: NodeTypes.COMMENT
+    })
+  })
+
+  it('explicitly create fragments', () => {
+    const App = {
+      render() {
+        return h('div', [h(Fragment, [h('div', 'one'), 'two'])])
+      }
+    }
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+    const parent = root.children[0] as TestElement
+    expect(serialize(parent)).toBe(`<div><!----><div>one</div>two<!----></div>`)
+  })
+
+  it('patch fragment children (manual, keyed)', async () => {
+    const state = reactive({ ok: true })
+    const App = {
+      render() {
+        return state.ok
+          ? [h('div', { key: 1 }, 'one'), h('div', { key: 2 }, 'two')]
+          : [h('div', { key: 2 }, 'two'), h('div', { key: 1 }, 'one')]
+      }
+    }
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+
+    expect(serialize(root)).toBe(
+      `<div><!----><div>one</div><div>two</div><!----></div>`
+    )
+
+    resetOps()
+    state.ok = false
+    await nextTick()
+    expect(serialize(root)).toBe(
+      `<div><!----><div>two</div><div>one</div><!----></div>`
+    )
+    const ops = dumpOps()
+    // should be moving nodes instead of re-creating or patching them
+    expect(ops).toMatchObject([
+      {
+        type: NodeOpTypes.INSERT
+      }
+    ])
+  })
+
+  it('patch fragment children (manual, unkeyed)', async () => {
+    const state = reactive({ ok: true })
+    const App = {
+      render() {
+        return state.ok
+          ? [h('div', 'one'), h('div', 'two')]
+          : [h('div', 'two'), h('div', 'one')]
+      }
+    }
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+
+    expect(serialize(root)).toBe(
+      `<div><!----><div>one</div><div>two</div><!----></div>`
+    )
+
+    resetOps()
+    state.ok = false
+    await nextTick()
+    expect(serialize(root)).toBe(
+      `<div><!----><div>two</div><div>one</div><!----></div>`
+    )
+    const ops = dumpOps()
+    // should be patching nodes instead of moving or re-creating them
+    expect(ops).toMatchObject([
+      {
+        type: NodeOpTypes.SET_ELEMENT_TEXT
+      },
+      {
+        type: NodeOpTypes.SET_ELEMENT_TEXT
+      }
+    ])
+  })
+
+  it('patch fragment children (compiler generated, unkeyed)', async () => {
+    const state = reactive({ ok: true })
+    const App = {
+      render() {
+        return state.ok
+          ? createVNode(
+              Fragment,
+              0,
+              [h('div', 'one'), 'two'],
+              PatchFlags.UNKEYED
+            )
+          : createVNode(
+              Fragment,
+              0,
+              [h('div', 'foo'), 'bar', 'baz'],
+              PatchFlags.UNKEYED
+            )
+      }
+    }
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+
+    expect(serialize(root)).toBe(`<div><!----><div>one</div>two<!----></div>`)
+
+    state.ok = false
+    await nextTick()
+    expect(serialize(root)).toBe(
+      `<div><!----><div>foo</div>barbaz<!----></div>`
+    )
+  })
+
+  it('patch fragment children (compiler generated, keyed)', async () => {
+    const state = reactive({ ok: true })
+    const App = {
+      render() {
+        return state.ok
+          ? createVNode(
+              Fragment,
+              0,
+              [h('div', { key: 1 }, 'one'), h('div', { key: 2 }, 'two')],
+              PatchFlags.KEYED
+            )
+          : createVNode(
+              Fragment,
+              0,
+              [h('div', { key: 2 }, 'two'), h('div', { key: 1 }, 'one')],
+              PatchFlags.KEYED
+            )
+      }
+    }
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+
+    expect(serialize(root)).toBe(
+      `<div><!----><div>one</div><div>two</div><!----></div>`
+    )
+
+    resetOps()
+    state.ok = false
+    await nextTick()
+    expect(serialize(root)).toBe(
+      `<div><!----><div>two</div><div>one</div><!----></div>`
+    )
+    const ops = dumpOps()
+    // should be moving nodes instead of re-creating or patching them
+    expect(ops).toMatchObject([
+      {
+        type: NodeOpTypes.INSERT
+      }
+    ])
+  })
+
+  it('move fragment', async () => {
+    const state = reactive({ ok: true })
+    const App = {
+      render() {
+        return state.ok
+          ? h('div', [
+              h('div', { key: 1 }, 'outer'),
+              h(Fragment, { key: 2 }, [
+                h('div', { key: 1 }, 'one'),
+                h('div', { key: 2 }, 'two')
+              ])
+            ])
+          : h('div', [
+              h(Fragment, { key: 2 }, [
+                h('div', { key: 2 }, 'two'),
+                h('div', { key: 1 }, 'one')
+              ]),
+              h('div', { key: 1 }, 'outer')
+            ])
+      }
+    }
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+    const parent = root.children[0] as TestElement
+
+    expect(serialize(parent)).toBe(
+      `<div><div>outer</div><!----><div>one</div><div>two</div><!----></div>`
+    )
+
+    resetOps()
+    state.ok = false
+    await nextTick()
+    expect(serialize(parent)).toBe(
+      `<div><!----><div>two</div><div>one</div><!----><div>outer</div></div>`
+    )
+    const ops = dumpOps()
+    // should be moving nodes instead of re-creating them
+    expect(ops).toMatchObject([
+      // 1. re-order inside the fragment
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'element' } },
+      // 2. move entire fragment, including anchors
+      // not the most efficient move, but this case is super rare
+      // and optimizing for this special case complicates the algo quite a bit
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'comment' } },
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'element' } },
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'element' } },
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'comment' } }
+    ])
+  })
+
+  it('handle nested fragments', async () => {
+    const state = reactive({ ok: true })
+    const App = {
+      render() {
+        return state.ok
+          ? [
+              h('div', { key: 1 }, 'outer'),
+              h(Fragment, { key: 2 }, [
+                h('div', { key: 1 }, 'one'),
+                h('div', { key: 2 }, 'two')
+              ])
+            ]
+          : [
+              h(Fragment, { key: 2 }, [
+                h('div', { key: 2 }, 'two'),
+                h('div', { key: 1 }, 'one')
+              ]),
+              h('div', { key: 1 }, 'outer')
+            ]
+      }
+    }
+
+    const root = nodeOps.createElement('div')
+    render(h(App), root)
+
+    expect(serialize(root)).toBe(
+      `<div><!----><div>outer</div><!----><div>one</div><div>two</div><!----><!----></div>`
+    )
+
+    resetOps()
+    state.ok = false
+    await nextTick()
+    expect(serialize(root)).toBe(
+      `<div><!----><!----><div>two</div><div>one</div><!----><div>outer</div><!----></div>`
+    )
+    const ops = dumpOps()
+    // should be moving nodes instead of re-creating them
+    expect(ops).toMatchObject([
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'element' } },
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'comment' } },
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'element' } },
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'element' } },
+      { type: NodeOpTypes.INSERT, targetNode: { type: 'comment' } }
+    ])
+  })
+})

packages/runtime-core/src/createRenderer.ts

@@ -694,7 +694,9 @@ export function createRenderer(options: RendererOptions) {
       if (prevShapeFlag & ShapeFlags.ARRAY_CHILDREN) {
         unmountChildren(c1 as VNode[], parentComponent)
       }
-      hostSetElementText(container, c2 as string)
+      if (c2 !== c1) {
+        hostSetElementText(container, c2 as string)
+      }
     } else {
       if (prevShapeFlag & ShapeFlags.TEXT_CHILDREN) {
         hostSetElementText(container, '')

packages/runtime-core/src/h.ts

@@ -0,0 +1,49 @@
+import { VNodeTypes, VNode, createVNode } from './vnode'
+import { isObject, isArray } from '@vue/shared'
+
+// `h` is a more user-friendly version of `createVNode` that allows omitting the
+// props when possible. It is intended for manually written render functions.
+// Compiler-generated code uses `createVNode` because
+// 1. it is monomorphic and avoids the extra call overhead
+// 2. it allows specifying patchFlags for optimization
+
+/*
+// type only
+h('div')
+
+// type + props
+h('div', {})
+
+// type + omit props + children
+// Omit props does NOT support named slots
+h('div', []) // array
+h('div', () => {}) // default slot
+h('div', 'foo') // text
+
+// type + props + children
+h('div', {}, []) // array
+h('div', {}, () => {}) // default slot
+h('div', {}, {}) // named slots
+h('div', {}, 'foo') // text
+
+// named slots without props requires explicit `null` to avoid ambiguity
+h('div', null, {})
+**/
+
+export function h(
+  type: VNodeTypes,
+  propsOrChildren?: any,
+  children?: any
+): VNode {
+  if (arguments.length === 2) {
+    if (isObject(propsOrChildren) && !isArray(propsOrChildren)) {
+      // props without children
+      return createVNode(type, propsOrChildren)
+    } else {
+      // omit props
+      return createVNode(type, null, propsOrChildren)
+    }
+  } else {
+    return createVNode(type, propsOrChildren, children)
+  }
+}

packages/runtime-core/src/index.ts

@@ -10,6 +10,7 @@ export * from './apiInject'
 // Advanced API ----------------------------------------------------------------
 
 // For raw render function users
+export { h } from './h'
 export {
   createVNode,
   cloneVNode,

packages/runtime-core/src/vnode.ts

@@ -18,7 +18,7 @@ export const Text = Symbol('Text')
 export const Empty = Symbol('Empty')
 export const Portal = Symbol('Portal')
 
-type VNodeTypes =
+export type VNodeTypes =
   | string
   | Function
   | Object

packages/runtime-test/__tests__/testRuntime.spec.ts

@@ -1,5 +1,5 @@
 import {
-  createVNode as h,
+  h,
   render,
   nodeOps,
   NodeTypes,
@@ -125,7 +125,7 @@ describe('test renderer', () => {
           {
             id: 'test'
           },
-          [h('span', 0, 'foo'), 'hello']
+          [h('span', 'foo'), 'hello']
         )
       }
     }

packages/runtime-test/src/nodeOps.ts

@@ -145,7 +145,8 @@ function insert(child: TestNode, parent: TestElement, ref?: TestNode | null) {
     parentNode: parent,
     refNode: ref
   })
-  remove(child)
+  // remove the node first, but don't log it as a REMOVE op
+  remove(child, false)
   if (refIndex === undefined) {
     parent.children.push(child)
     child.parentNode = parent
@@ -155,14 +156,16 @@ function insert(child: TestNode, parent: TestElement, ref?: TestNode | null) {
   }
 }
 
-function remove(child: TestNode) {
+function remove(child: TestNode, logOp: boolean = true) {
   const parent = child.parentNode
   if (parent != null) {
-    logNodeOp({
-      type: NodeOpTypes.REMOVE,
-      targetNode: child,
-      parentNode: parent
-    })
+    if (logOp) {
+      logNodeOp({
+        type: NodeOpTypes.REMOVE,
+        targetNode: child,
+        parentNode: parent
+      })
+    }
     const i = parent.children.indexOf(child)
     if (i > -1) {
       parent.children.splice(i, 1)