[bugfix] Stepper: 修复组件不传 max 情况下，默认置灰的问题 (#269)

* 修复stepper文档错误

* 采用极大数字来代替 infinity

example/pages/stepper/index.js

@@ -2,8 +2,7 @@ Page(Object.assign({}, {
   data: {
     stepper1: {
       stepper: 10,
-      min: 1,
-      max: 20
+      min: 1
     },
     stepper2: {
       stepper: 10,

example/pages/stepper/index.wxml

@@ -4,7 +4,6 @@
       <zan-stepper
         stepper="{{ stepper1.stepper }}"
         min="{{ stepper1.min }}"
-        max="{{ stepper1.max }}"
         data-component-id="stepper1"
         bind:change="handleZanStepperChange"
       >

packages/stepper/README.md

@@ -30,19 +30,11 @@ Page({
   },
 
   handleZanStepperChange({
-
     // stepper 代表操作后，应该要展示的数字，需要设置到数据对象里，才会更新页面展示
-    detail: stepper,
-
-    // 模板中传入的 componentId，用于区分一个页面上的多个stepper
-    target: {
-      dataset: {
-        componentId
-      }
-    }
+    detail: stepper
   }) {
     this.setData({
-      [`${componentId}.stepper`]: stepper
+      'stepper.stepper': stepper
     });
   }
 });
@@ -57,7 +49,6 @@ Page({
   stepper="{{ stepper.stepper }}"
   min="{{ stepper.min }}"
   max="{{ stepper.max }}"
-  component-id="stepper"
   bind:change="handleZanStepperChange"
 >
 </zan-stepper>
@@ -72,7 +63,6 @@ Page({
 | min | 计数器最小值 | Number | `1` | |
 | max | 计数器最大值 | Number | 无穷大 | |
 | step | 步数 | Number | `1` | |
-| componentId | 用于区分输入框之间的唯一名称 | String | - | |
 
 ### Event
 

packages/stepper/index.js

@@ -1,3 +1,7 @@
+// Note that the bitwise operators and shift operators operate on 32-bit ints
+// so in that case, the max safe integer is 2^31-1, or 2147483647
+const VERY_LARGE_NUMBER = 2147483647;
+
 Component({
   properties: {
     size: String,
@@ -11,7 +15,7 @@ Component({
     },
     max: {
       type: Number,
-      value: Infinity
+      value: VERY_LARGE_NUMBER
     },
     step: {
       type: Number,