fix array asset component name check

Author: yyx990803

src/util/options.js

@@ -281,10 +281,12 @@ function guardArrayAssets (assets) {
     var asset
     while (i--) {
       asset = assets[i]
-      var id = asset.name || (asset.options && asset.options.name)
+      var id = typeof asset === 'function'
+        ? ((asset.options && asset.options.name) || asset.id)
+        : (asset.name || asset.id)
       if (!id) {
         process.env.NODE_ENV !== 'production' && _.warn(
-          'Array-syntax assets must provide a "name" field.'
+          'Array-syntax assets must provide a "name" or "id" field.'
         )
       } else {
         res[id] = asset

test/unit/specs/util/options_spec.js

@@ -327,7 +327,20 @@ describe('Util - Option merging', function () {
       components: [{}]
     }
     merge(a, b)
-    expect(hasWarned(_, 'must provide a "name" field')).toBe(true)
+    expect(hasWarned(_, 'must provide a "name" or "id" field')).toBe(true)
+  })
+
+  it('warn Array async component without id', function () {
+    var a = {
+      components: {
+        a: Vue.extend({})
+      }
+    }
+    var b = {
+      components: [function () {}]
+    }
+    merge(a, b)
+    expect(hasWarned(_, 'must provide a "name" or "id" field')).toBe(true)
   })
 
 })