bugfix (redux-form) Add missing parameter to onChange method (#29636)

* - [redux-form] add missing parameter to onChange function

* - test added

* - fix tests

types/redux-form/index.d.ts

@@ -10,6 +10,7 @@
 //                 Ethan Resnick <https://github.com/ethanresnick>
 //                 Tim de Koning <https://github.com/reggino>
 //                 Maddi Joyce <https://github.com/maddijoyce>
+//                 Kamil Wojcik <https://github.com/smifun>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 import {

types/redux-form/lib/reduxForm.d.ts

@@ -111,7 +111,7 @@ export interface ConfigProps<FormData = {}, P = {}, ErrorType = string> {
     initialValues?: Partial<FormData>;
     keepDirtyOnReinitialize?: boolean;
     updateUnregisteredFields?: boolean;
-    onChange?(values: Partial<FormData>, dispatch: Dispatch<any>, props: P & InjectedFormProps<FormData, P, ErrorType>): void;
+    onChange?(values: Partial<FormData>, dispatch: Dispatch<any>, props: P & InjectedFormProps<FormData, P, ErrorType>, previousValues: Partial<FormData>): void;
     onSubmit?: FormSubmitHandler<FormData, P & InjectedFormProps<FormData, P, ErrorType>, ErrorType> | SubmitHandler<FormData, P & InjectedFormProps<FormData, P, ErrorType>, ErrorType>;
     onSubmitFail?(
         errors: FormErrors<FormData, ErrorType> | undefined,

types/redux-form/redux-form-tests.tsx

@@ -231,6 +231,14 @@ const testFormWithInitialValuesAndValidationDecorator = reduxForm<MultivalueForm
     }
 });
 
+const testFormWithChangeFunctionDecorator = reduxForm<TestFormData, TestFormComponentProps>({
+    form: "testWithValidation",
+    onChange: (values: Partial<TestFormData>,
+        dispatch: Dispatch<any>,
+        props: TestFormComponentProps & InjectedFormProps<TestFormData, TestFormComponentProps>,
+        previousValues: Partial<TestFormData>) => {}
+});
+
 type TestProps = {} & InjectedFormProps<TestFormData>;
 const Test = reduxForm<TestFormData>({
     form : "test"