fix bugs and add new features (#25)

* fix bugs and add new features

* add unit test

* fix tab/tag/datetime-picker bugs

packages/steps/src/steps.vue

@@ -1,7 +1,7 @@
 <template>
   <div class="van-steps" :class="`van-steps--${steps.length}`">
     <div class="van-steps__status" v-if="title || description">
-      <div class="van-steps__icon" v-if="icon || $slot.icon">
+      <div class="van-steps__icon" v-if="icon || $slots.icon">
         <slot name="icon">
           <van-icon :name="icon" :class="iconClass"></van-icon>
         </slot>

packages/tab/src/tabs.vue

@@ -35,6 +35,11 @@
       type: {
         type: String,
         default: 'line'
+      },
+      // 切换tab的动画时间
+      duration: {
+        type: Number,
+        default: 0.3
       }
     },
 
@@ -66,7 +71,8 @@
 
         return {
           width: offsetWidth,
-          transform: `translate3d(${offsetLeft}, 0px, 0px)`
+          transform: `translate3d(${offsetLeft}, 0px, 0px)`,
+          transitionDuration: `${this.duration}s`
         };
       }
     },

packages/tag/src/main.vue

@@ -5,10 +5,17 @@
 </template>
 
 <script>
+  const ALLOW_TYPE = ['danger', 'success', 'primary'];
+
   export default {
     name: 'van-tag',
     props: {
-      type: String,
+      type: {
+        type: String,
+        validator: function (val) {
+          return ~ALLOW_TYPE.indexOf(val);
+        }
+      },
       mark: Boolean,
       plain: Boolean
     }

packages/vant-css/src/tab.css

@@ -86,7 +86,6 @@
     font-size: 14px;
     line-height: 44px;
     box-sizing: border-box;
-    transition: color .3s cubic-bezier(.645, .045, .355, 1);
     cursor: pointer;
     text-align: center;
     float: left;