fix some tests

fix merge issues

src/elements/GPElements/Button.module.css

@@ -0,0 +1,8 @@
+.button {
+    background-color: green;
+    border-radius: 5px;
+    border-width: 0;
+    color: white;
+    margin-right: 15px;
+    padding: 6px;
+}

src/elements/GPElements/Button.test.js

@@ -0,0 +1,32 @@
+import {shallow} from 'enzyme';
+import React from 'react';
+import {Button} from './Button';
+
+function prepareFetchApi(response) {
+    const mockJsonPromise = Promise.resolve(response);
+    const mockFetchPromise = Promise.resolve({
+        json: () => mockJsonPromise
+    });
+    return (jest.fn().mockImplementation(() => mockFetchPromise));
+}
+
+describe('<Button/>', function () {
+    it('renders without crashing ', function () {
+        const wrapper = shallow(<Button onClick={() => {}} title='test'/>);
+        wrapper.unmount();
+    });
+
+    it('renders title', function () {
+        const wrapper = shallow(<Button onClick={() => {}} title='test1'/>);
+        expect(wrapper.text()).toBe('test1');
+    });
+
+    it('test onclick handling', () => {
+        const func = jest.fn();
+        const wrapper = shallow(<Button onClick={func} title='test1'/>);
+
+        wrapper.find('button').simulate('click');
+
+        expect(func).toHaveBeenCalledTimes(1);
+    });
+});

src/elements/GPElements/Button.tsx

@@ -0,0 +1,16 @@
+import React from 'react';
+import style from './Button.module.css';
+
+interface ButtonProps {
+    title: string;
+    onClick?: () => void;
+    color?: React.CSSProperties;
+}
+
+export function Button(props: ButtonProps): JSX.Element {
+    return (
+        <button className={style.button} style={props.color} onClick={props.onClick}>
+            {props.title}
+        </button>
+    );
+}