Revert "fix(compiler-core): generate incremental keys for v-if/else-i…

…f/else chains (vuejs#1589)"

This reverts commit 64c7b2f.

packages/compiler-core/__tests__/transforms/__snapshots__/vIf.spec.ts.snap

@@ -14,46 +14,6 @@ return function render(_ctx, _cache) {
 }"
 `;
 
-exports[`compiler: v-if codegen increasing key: v-if + v-else-if + v-else 1`] = `
-"const _Vue = Vue
-
-return function render(_ctx, _cache) {
-  with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
-
-    return (_openBlock(), _createBlock(_Fragment, null, [
-      ok
-        ? (_openBlock(), _createBlock(\\"div\\", { key: 0 }))
-        : (_openBlock(), _createBlock(\\"p\\", { key: 1 })),
-      another
-        ? (_openBlock(), _createBlock(\\"div\\", { key: 2 }))
-        : orNot
-          ? (_openBlock(), _createBlock(\\"p\\", { key: 3 }))
-          : (_openBlock(), _createBlock(\\"p\\", { key: 4 }))
-    ], 64 /* STABLE_FRAGMENT */))
-  }
-}"
-`;
-
-exports[`compiler: v-if codegen multiple v-if that are sibling nodes should have different keys 1`] = `
-"const _Vue = Vue
-
-return function render(_ctx, _cache) {
-  with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
-
-    return (_openBlock(), _createBlock(_Fragment, null, [
-      ok
-        ? (_openBlock(), _createBlock(\\"div\\", { key: 0 }))
-        : _createCommentVNode(\\"v-if\\", true),
-      orNot
-        ? (_openBlock(), _createBlock(\\"p\\", { key: 1 }))
-        : _createCommentVNode(\\"v-if\\", true)
-    ], 64 /* STABLE_FRAGMENT */))
-  }
-}"
-`;
-
 exports[`compiler: v-if codegen template v-if 1`] = `
 "const _Vue = Vue
 

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

@@ -29,19 +29,16 @@ import { createObjectMatcher } from '../testUtils'
 function parseWithIfTransform(
   template: string,
   options: CompilerOptions = {},
-  returnIndex: number = 0,
-  childrenLen: number = 1
+  returnIndex: number = 0
 ) {
   const ast = parse(template, options)
   transform(ast, {
     nodeTransforms: [transformIf, transformSlotOutlet, transformElement],
     ...options
   })
   if (!options.onError) {
-    expect(ast.children.length).toBe(childrenLen)
-    for (let i = 0; i < childrenLen; i++) {
-      expect(ast.children[i].type).toBe(NodeTypes.IF)
-    }
+    expect(ast.children.length).toBe(1)
+    expect(ast.children[0].type).toBe(NodeTypes.IF)
   }
   return {
     root: ast,
@@ -487,68 +484,6 @@ describe('compiler: v-if', () => {
       expect(generate(root).code).toMatchSnapshot()
     })
 
-    test('multiple v-if that are sibling nodes should have different keys', () => {
-      const { root } = parseWithIfTransform(
-        `<div v-if="ok"/><p v-if="orNot"/>`,
-        {},
-        0 /* returnIndex, just give the default value */,
-        2 /* childrenLen */
-      )
-
-      const ifNode = root.children[0] as IfNode & {
-        codegenNode: IfConditionalExpression
-      }
-      expect(ifNode.codegenNode.consequent).toMatchObject({
-        tag: `"div"`,
-        props: createObjectMatcher({ key: `[0]` })
-      })
-      const ifNode2 = root.children[1] as IfNode & {
-        codegenNode: IfConditionalExpression
-      }
-      expect(ifNode2.codegenNode.consequent).toMatchObject({
-        tag: `"p"`,
-        props: createObjectMatcher({ key: `[1]` })
-      })
-      expect(generate(root).code).toMatchSnapshot()
-    })
-
-    test('increasing key: v-if + v-else-if + v-else', () => {
-      const { root } = parseWithIfTransform(
-        `<div v-if="ok"/><p v-else/><div v-if="another"/><p v-else-if="orNot"/><p v-else/>`,
-        {},
-        0 /* returnIndex, just give the default value */,
-        2 /* childrenLen */
-      )
-      const ifNode = root.children[0] as IfNode & {
-        codegenNode: IfConditionalExpression
-      }
-      expect(ifNode.codegenNode.consequent).toMatchObject({
-        tag: `"div"`,
-        props: createObjectMatcher({ key: `[0]` })
-      })
-      expect(ifNode.codegenNode.alternate).toMatchObject({
-        tag: `"p"`,
-        props: createObjectMatcher({ key: `[1]` })
-      })
-      const ifNode2 = root.children[1] as IfNode & {
-        codegenNode: IfConditionalExpression
-      }
-      expect(ifNode2.codegenNode.consequent).toMatchObject({
-        tag: `"div"`,
-        props: createObjectMatcher({ key: `[2]` })
-      })
-      const branch = ifNode2.codegenNode.alternate as IfConditionalExpression
-      expect(branch.consequent).toMatchObject({
-        tag: `"p"`,
-        props: createObjectMatcher({ key: `[3]` })
-      })
-      expect(branch.alternate).toMatchObject({
-        tag: `"p"`,
-        props: createObjectMatcher({ key: `[4]` })
-      })
-      expect(generate(root).code).toMatchSnapshot()
-    })
-
     test('key injection (only v-bind)', () => {
       const {
         node: { codegenNode }

packages/compiler-core/src/transforms/vIf.ts

@@ -39,34 +39,21 @@ export const transformIf = createStructuralDirectiveTransform(
   /^(if|else|else-if)$/,
   (node, dir, context) => {
     return processIf(node, dir, context, (ifNode, branch, isRoot) => {
-      // #1587: We need to dynamically increment the key based on the current
-      // node's sibling nodes, since chained v-if/else branches are
-      // rendered at the same depth
-      const siblings = context.parent!.children
-      let i = siblings.indexOf(ifNode)
-      let key = 0
-      while (i-- >= 0) {
-        const sibling = siblings[i]
-        if (sibling && sibling.type === NodeTypes.IF) {
-          key += sibling.branches.length
-        }
-      }
-
       // Exit callback. Complete the codegenNode when all children have been
       // transformed.
       return () => {
         if (isRoot) {
           ifNode.codegenNode = createCodegenNodeForBranch(
             branch,
-            key,
+            0,
             context
           ) as IfConditionalExpression
         } else {
           // attach this branch's codegen node to the v-if root.
           const parentCondition = getParentCondition(ifNode.codegenNode!)
           parentCondition.alternate = createCodegenNodeForBranch(
             branch,
-            key + ifNode.branches.length - 1,
+            ifNode.branches.length - 1,
             context
           )
         }