From 6b63ba2f453b3f9bbf9e9e2167030de42f76b5ac Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Mon, 13 Jul 2020 14:00:08 -0400
Subject: [PATCH] fix(compiler-dom): fix v-on .left .right modifier handling

---
 .../__tests__/transforms/vOn.spec.ts          | 36 +++++++++++++++++++
 packages/compiler-dom/src/transforms/vOn.ts   | 31 ++++++++++++----
 2 files changed, 60 insertions(+), 7 deletions(-)

diff --git a/packages/compiler-dom/__tests__/transforms/vOn.spec.ts b/packages/compiler-dom/__tests__/transforms/vOn.spec.ts
index adc063da2f5..57e9300cd1f 100644
--- a/packages/compiler-dom/__tests__/transforms/vOn.spec.ts
+++ b/packages/compiler-dom/__tests__/transforms/vOn.spec.ts
@@ -137,6 +137,42 @@ describe('compiler-dom: transform v-on', () => {
     })
   })
 
+  it('should wrap keys guard for static key event w/ left/right modifiers', () => {
+    const {
+      props: [prop]
+    } = parseWithVOn(`<div @keyup.left="test"/>`, {
+      prefixIdentifiers: true
+    })
+    expect(prop).toMatchObject({
+      type: NodeTypes.JS_PROPERTY,
+      value: {
+        callee: V_ON_WITH_KEYS,
+        arguments: [{ content: '_ctx.test' }, '["left"]']
+      }
+    })
+  })
+
+  it('should wrap both for dynamic key event w/ left/right modifiers', () => {
+    const {
+      props: [prop]
+    } = parseWithVOn(`<div @[e].left="test"/>`, {
+      prefixIdentifiers: true
+    })
+    expect(prop).toMatchObject({
+      type: NodeTypes.JS_PROPERTY,
+      value: {
+        callee: V_ON_WITH_KEYS,
+        arguments: [
+          {
+            callee: V_ON_WITH_MODIFIERS,
+            arguments: [{ content: `_ctx.test` }, `["left"]`]
+          },
+          '["left"]'
+        ]
+      }
+    })
+  })
+
   it('should not wrap normal guard if there is only keys guard', () => {
     const {
       props: [prop]
diff --git a/packages/compiler-dom/src/transforms/vOn.ts b/packages/compiler-dom/src/transforms/vOn.ts
index b4c013d43ff..f527d282ca9 100644
--- a/packages/compiler-dom/src/transforms/vOn.ts
+++ b/packages/compiler-dom/src/transforms/vOn.ts
@@ -7,7 +7,8 @@ import {
   createSimpleExpression,
   NodeTypes,
   createCompoundExpression,
-  ExpressionNode
+  ExpressionNode,
+  SimpleExpressionNode
 } from '@vue/compiler-core'
 import { V_ON_WITH_MODIFIERS, V_ON_WITH_KEYS } from '../runtimeHelpers'
 import { makeMap } from '@vue/shared'
@@ -19,14 +20,17 @@ const isNonKeyModifier = /*#__PURE__*/ makeMap(
     // system modifiers + exact
     `ctrl,shift,alt,meta,exact,` +
     // mouse
-    `left,middle,right`
+    `middle`
 )
+// left & right could be mouse or key modifiers based on event type
+const maybeKeyModifier = /*#__PURE__*/ makeMap('left,right')
 const isKeyboardEvent = /*#__PURE__*/ makeMap(
   `onkeyup,onkeydown,onkeypress`,
   true
 )
 
-const generateModifiers = (modifiers: string[]) => {
+const resolveModifiers = (key: ExpressionNode, modifiers: string[]) => {
+  const isStaticKey = key.type === NodeTypes.SIMPLE_EXPRESSION && key.isStatic
   const keyModifiers = []
   const nonKeyModifiers = []
   const eventOptionModifiers = []
@@ -39,10 +43,23 @@ const generateModifiers = (modifiers: string[]) => {
       eventOptionModifiers.push(modifier)
     } else {
       // runtimeModifiers: modifiers that needs runtime guards
-      if (isNonKeyModifier(modifier)) {
-        nonKeyModifiers.push(modifier)
+      if (maybeKeyModifier(modifier)) {
+        if (isStaticKey) {
+          if (isKeyboardEvent((key as SimpleExpressionNode).content)) {
+            keyModifiers.push(modifier)
+          } else {
+            nonKeyModifiers.push(modifier)
+          }
+        } else {
+          keyModifiers.push(modifier)
+          nonKeyModifiers.push(modifier)
+        }
       } else {
-        keyModifiers.push(modifier)
+        if (isNonKeyModifier(modifier)) {
+          nonKeyModifiers.push(modifier)
+        } else {
+          keyModifiers.push(modifier)
+        }
       }
     }
   }
@@ -82,7 +99,7 @@ export const transformOn: DirectiveTransform = (dir, node, context) => {
       keyModifiers,
       nonKeyModifiers,
       eventOptionModifiers
-    } = generateModifiers(modifiers)
+    } = resolveModifiers(key, modifiers)
 
     // normalize click.right and click.middle since they don't actually fire
     if (nonKeyModifiers.includes('right')) {