From f35f7e35cd48efc21e759752058c07a1ff32cfb6 Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Sat, 8 Oct 2016 14:15:05 -0400
Subject: [PATCH] add v-model dynamic type warning

---
 src/platforms/web/compiler/directives/model.js     |  9 +++++++++
 .../unit/features/directives/model-dynamic.spec.js | 14 ++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 test/unit/features/directives/model-dynamic.spec.js

diff --git a/src/platforms/web/compiler/directives/model.js b/src/platforms/web/compiler/directives/model.js
index 2c867887..a59752e6 100644
--- a/src/platforms/web/compiler/directives/model.js
+++ b/src/platforms/web/compiler/directives/model.js
@@ -15,6 +15,15 @@ export default function model (
   const modifiers = dir.modifiers
   const tag = el.tag
   const type = el.attrsMap.type
+  if (process.env.NODE_ENV !== 'production') {
+    const dynamicType = el.attrsMap['v-bind:type'] || el.attrsMap[':type']
+    if (tag === 'input' && dynamicType) {
+      warn(
+        `<input :type="${dynamicType}" v-model="${value}">:\n` +
+        `v-model does not support dynamic input types. Use v-if branches instead.`
+      )
+    }
+  }
   if (tag === 'select') {
     return genSelect(el, value)
   } else if (tag === 'input' && type === 'checkbox') {
diff --git a/test/unit/features/directives/model-dynamic.spec.js b/test/unit/features/directives/model-dynamic.spec.js
new file mode 100644
index 00000000..87a4cb5c
--- /dev/null
+++ b/test/unit/features/directives/model-dynamic.spec.js
@@ -0,0 +1,14 @@
+import Vue from 'vue'
+
+describe('Directive v-model dynamic input type', () => {
+  it('should warn', function () {
+    new Vue({
+      data: {
+        type: 'text',
+        text: 'hi'
+      },
+      template: `<input :type="type" v-model="text">`
+    }).$mount()
+    expect(`v-model does not support dynamic input types`).toHaveBeenWarned()
+  })
+})