fix(input): numeric input v-model 为 null 时会报错

src/components/dao-input/dao-numeric-input.vue

@@ -19,18 +19,19 @@
 <script>
 
   import DaoTriangle from './dao-triangle/dao-triangle.vue';
+  import { _toString } from '../../utils/assist';
 
   function isInt(num) {
     if (num === undefined) return false;
-    return /^(0|[1-9][0-9]*)$/.test(num >= 0 ? num : num.toString().slice(1));
+    return /^(0|[1-9][0-9]*)$/.test(num >= 0 ? num : _toString(num).slice(1));
   }
 
   function isFloat(num) {
     return /^(-?\d+)(\.\d+)?$/.test(num);
   }
 
   function isEndWithDot(num) {
-    const arr = num.toString().split('.');
+    const arr = _toString(num).split('.');
     if (arr.length === 2 && isInt(arr[0]) && arr[1] === '') {
       return true;
     }
@@ -117,7 +118,7 @@
       onBlur() {
         this.dirty = true;
         if (this.type === 'float' && isEndWithDot(this.num)) {
-          this.preCheck(this.num.toString().split('.').shift());
+          this.preCheck(_toString(this.num).split('.').shift());
         }
       },
       preCheck(num) {

src/utils/assist.js

@@ -17,6 +17,7 @@ export { default as _chunk } from 'lodash/chunk';
 export { default as _get } from 'lodash/get';
 export { default as _flatten } from 'lodash/flatten';
 export { default as _toNumber } from 'lodash/toNumber';
+export { default as _toString } from 'lodash/toString';
 export { default as _findIndex } from 'lodash/findIndex';
 export { default as _merge } from 'lodash/merge';
 export { default as _uniqBy } from 'lodash/uniqBy';