Implement test render function for global theme and modes

It renders the passed components with the global theme and modes
provided through the `Root` core container component. This is necessary
for all styled components that make use of any theme properties either
simple values or functions.

Associated epic: 38
GH-64

test/__utils__/index.js

@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2018-present Arctic Ice Studio <[email protected]>
+ * Copyright (C) 2018-present Sven Greb <[email protected]>
+ *
+ * Project:    Nord Docs
+ * Repository: https://github.com/arcticicestudio/nord-docs
+ * License:    MIT
+ */
+
+/**
+ * @file Provides test utility functions and classes.
+ * @author Arctic Ice Studio <[email protected]>
+ * @author Sven Greb <[email protected]>
+ * @since 0.3.0
+ */
+
+import renderWithTheme from "./renderWithTheme";
+
+/* eslint-disable-next-line import/prefer-default-export */
+export { renderWithTheme };

test/__utils__/renderWithTheme.jsx

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2018-present Arctic Ice Studio <[email protected]>
+ * Copyright (C) 2018-present Sven Greb <[email protected]>
+ *
+ * Project:    Nord Docs
+ * Repository: https://github.com/arcticicestudio/nord-docs
+ * License:    MIT
+ */
+
+import React from "react";
+import { render } from "react-testing-library";
+
+import Root from "containers/core/Root";
+
+/**
+ * Renders the passed components with the global theme and modes provided through the `Root` core container component.
+ *
+ * @method renderWithTheme
+ * @author Arctic Ice Studio <[email protected]>
+ * @author Sven Greb <[email protected]>
+ * @since 0.3.0
+ */
+const renderWithTheme = components => render(<Root>{components}</Root>);
+
+export default renderWithTheme;