Convert old tests to use "react-testing-library"

app/soapbox/features/ui/components/__tests__/compose-button.test.js

@@ -1,26 +1,39 @@
+import { fireEvent, render, screen } from '@testing-library/react';
 import { Map as ImmutableMap } from 'immutable';
 import React from 'react';
+import { IntlProvider } from 'react-intl';
+import { Provider } from 'react-redux';
+import '@testing-library/jest-dom';
 
 import { MODAL_OPEN } from 'soapbox/actions/modals';
+import { mockStore } from 'soapbox/jest/test-helpers';
 import rootReducer from 'soapbox/reducers';
-import { createComponent, mockStore } from 'soapbox/test_helpers';
 
 import ComposeButton from '../compose-button';
 
+const store = mockStore(rootReducer(ImmutableMap(), {}));
+const renderComposeButton = () => {
+  render(
+    <Provider store={store}>
+      <IntlProvider locale='en'>
+        <ComposeButton />
+      </IntlProvider>
+    </Provider>,
+  );
+};
+
 describe('<ComposeButton />', () => {
   it('renders a button element', () => {
-    const component = createComponent(<ComposeButton />);
-    const tree = component.toJSON();
+    renderComposeButton();
 
-    expect(tree).toMatchSnapshot();
+    expect(screen.getByRole('button')).toHaveTextContent('Compose');
   });
 
   it('dispatches the MODAL_OPEN action', () => {
-    const store = mockStore(rootReducer(ImmutableMap(), {}));
-    const component = createComponent(<ComposeButton />, { store });
+    renderComposeButton();
 
     expect(store.getActions().length).toEqual(0);
-    component.root.findByType('button').props.onClick();
+    fireEvent.click(screen.getByRole('button'));
     expect(store.getActions()[0].type).toEqual(MODAL_OPEN);
   });
 });