修复表单组件样式和单元测试用例 (#7)

* fix: loading small style, search style and dialog style

* fix: scroll to top

* fix mobile scroll

* fix scroll to top

* 文档细节优化

* unit test

* dialog and image-preview unit test

* fix form component style

* fix radio and checkbox style

* fix search component style

packages/dialog/src/dialog.js

@@ -9,13 +9,8 @@ let instance;
 let dialogQueue = [];
 
 const defaultCallback = action => {
+  /* istanbul ignore else */
   if (currentDialog) {
-    const callback = currentDialog.callback;
-
-    if (typeof callback === 'function') {
-      callback(action);
-    }
-
     if (currentDialog.resolve && action === 'confirm') {
       currentDialog.resolve(action);
     } else if (currentDialog.reject && action === 'cancel') {
@@ -43,6 +38,7 @@ const showNextDialog = () => {
     const options = currentDialog.options;
 
     for (const prop in options) {
+      /* istanbul ignore else */
       if (options.hasOwnProperty(prop)) {
         instance[prop] = options[prop];
       }

packages/dialog/src/dialog.vue

@@ -60,12 +60,14 @@ export default {
     },
 
     close() {
+      /* istanbul ignore if */
       if (this.closing) return;
 
       this.closing = true;
 
       this.value = false;
 
+      /* istanbul ignore else */
       if (this.lockOnScroll) {
         setTimeout(() => {
           if (this.overlay && this.bodyOverflow !== 'hidden') {