Fix #12319: .exact modifier : Failed to generate render function

src/compiler/codegen/events.ts

@@ -114,12 +114,13 @@ function genHandler(
         }
       } else if (key === 'exact') {
         const modifiers = handler.modifiers
-        genModifierCode += genGuard(
-          ['ctrl', 'shift', 'alt', 'meta']
-            .filter(keyModifier => !modifiers[keyModifier])
-            .map(keyModifier => `$event.${keyModifier}Key`)
-            .join('||')
-        )
+        const condition = ['ctrl', 'shift', 'alt', 'meta']
+          .filter(keyModifier => !modifiers[keyModifier])
+          .map(keyModifier => `$event.${keyModifier}Key`)
+          .join('||')
+        if (condition) {
+          genModifierCode += genGuard(condition)
+        }
       } else {
         keys.push(key)
       }

test/unit/features/directives/on.spec.ts

@@ -324,6 +324,34 @@ describe('Directive v-on', () => {
     expect(spy.mock.calls.length).toBe(1)
   })
 
+  // #12319
+  it('should support all system modifiers with exact', () => {
+    vm = new Vue({
+      el,
+      template: `
+        <div>
+          <input ref="input" @keydown.ctrl.shift.alt.meta.exact="foo">
+        </div>
+      `,
+      methods: { foo: spy }
+    })
+
+    // should not trigger without all modifiers
+    triggerEvent(vm.$refs.input, 'keydown', e => {
+      e.ctrlKey = true
+    })
+    expect(spy.mock.calls.length).toBe(0)
+
+    // should trigger with all modifiers
+    triggerEvent(vm.$refs.input, 'keydown', e => {
+      e.ctrlKey = true
+      e.shiftKey = true
+      e.altKey = true
+      e.metaKey = true
+    })
+    expect(spy.mock.calls.length).toBe(1)
+  })
+
   it('should support number keyCode', () => {
     vm = new Vue({
       el,

test/unit/modules/compiler/codegen.spec.ts

@@ -455,6 +455,11 @@ describe('codegen', () => {
       '<input @click.ctrl.exact="onClick">',
       `with(this){return _c('input',{on:{"click":function($event){if(!$event.ctrlKey)return null;if($event.shiftKey||$event.altKey||$event.metaKey)return null;return onClick.apply(null, arguments)}}})}`
     )
+    // #12319
+    assertCodegen(
+      '<input @keydown.ctrl.shift.alt.meta.exact="onClick">',
+      `with(this){return _c('input',{on:{"keydown":function($event){if(!$event.ctrlKey)return null;if(!$event.shiftKey)return null;if(!$event.altKey)return null;if(!$event.metaKey)return null;return onClick.apply(null, arguments)}}})}`
+    )
   })
 
   it('generate events with multiple modifiers', () => {