prefix deprecation warning

Author: yyx990803

src/config.js

@@ -1,13 +1,5 @@
 module.exports = {
 
-  /**
-   * The prefix to look for when parsing directives.
-   *
-   * @type {String}
-   */
-
-  prefix: 'v-',
-
   /**
    * Whether to print debug messages.
    * Also enables stack trace for warnings.
@@ -104,6 +96,25 @@ module.exports = {
 
 }
 
+/**
+ * The prefix to look for when parsing directives.
+ *
+ * @type {String}
+ */
+
+var prefix = 'v-'
+Object.defineProperty(module.exports, 'prefix', {
+  get: function () {
+    return prefix
+  },
+  set: function (val) {
+    prefix = val
+    if (process.env.NODE_ENV !== 'production') {
+      require('./util').deprecation.PREFIX()
+    }
+  }
+})
+
 /**
  * Interpolation delimiters.
  * We need to mark the changed flag so that the text parser

src/deprecations.js

@@ -220,6 +220,13 @@ if (process.env.NODE_ENV !== 'production') {
         'It is no longer necessary to declare literal directives in 1.0.0. Just ' +
         'use the dot-equal syntax (v-dir.="string") to indicate a literal value.'
       )
+    },
+
+    PREFIX: function () {
+      warn(
+        'The "prefix" global config will be deprecated in 1.0.0. All directives ' +
+        'will consistently use the v- or v. prefixes.'
+      )
     }
 
   }

test/unit/specs/misc_spec.js

@@ -358,4 +358,17 @@ describe('Misc', function () {
     })
     expect(hasWarned(__, 'Unknown custom element')).toBe(true)
   })
+
+  it('changing prefix', function () {
+    Vue.config.prefix = 'lol-'
+    var vm = new Vue({
+      el: document.createElement('div'),
+      template: '<div lol-text="text"></div>',
+      data: {
+        text: 'hi'
+      }
+    })
+    expect(vm.$el.textContent).toBe('hi')
+    Vue.config.prefix = 'v-'
+  })
 })