Fix type definition of ValueType and InputNumber onChange (#482)

Resolves #481

Author: fnimick

src/InputNumber.tsx

@@ -78,7 +78,7 @@ export interface InputNumberProps<T extends ValueType = ValueType>
   decimalSeparator?: string;
 
   onInput?: (text: string) => void;
-  onChange?: (value: T) => void;
+  onChange?: (value: T | null) => void;
   onPressEnter?: React.KeyboardEventHandler<HTMLInputElement>;
 
   onStep?: (value: T, info: { offset: ValueType; type: 'up' | 'down' }) => void;

src/utils/MiniDecimal.ts

@@ -3,7 +3,7 @@
 import { getNumberPrecision, isE, num2str, trimNumber, validateNumber } from './numberUtil';
 import { supportBigInt } from './supportUtil';
 
-export type ValueType = string | number | null;
+export type ValueType = string | number;
 
 export interface DecimalClass {
   add: (value: ValueType) => DecimalClass;