Adding HTML lang attribute and description metadata

src/components/Metadata/__snapshots__/test.js.snap

@@ -4,6 +4,11 @@ exports[`Metadata rendering 1`] = `
 <HelmetWrapper
   defer={true}
   encodeSpecialCharacters={true}
+  htmlAttributes={
+    Object {
+      "lang": "test-lang",
+    }
+  }
 >
   <title>
     Regexper
@@ -11,13 +16,22 @@ exports[`Metadata rendering 1`] = `
 </HelmetWrapper>
 `;
 
-exports[`Metadata rendering with a title 1`] = `
+exports[`Metadata rendering with a title and description 1`] = `
 <HelmetWrapper
   defer={true}
   encodeSpecialCharacters={true}
+  htmlAttributes={
+    Object {
+      "lang": "test-lang",
+    }
+  }
 >
   <title>
     Regexper - Testing
   </title>
+  <meta
+    content="Test description"
+    name="description"
+  />
 </HelmetWrapper>
 `;

src/components/Metadata/index.js

@@ -1,15 +1,29 @@
 import React from 'react';
 import PropTypes from 'prop-types';
+import { withNamespaces } from 'react-i18next';
 import { Helmet } from 'react-helmet';
 
-const Metadata = ({ title }) => (
-  <Helmet>
-    <title>{ title ? `Regexper - ${ title }` : 'Regexper' }</title>
-  </Helmet>
-);
+class Metadata extends React.PureComponent {
+  static propTypes = {
+    title: PropTypes.string,
+    description: PropTypes.string,
+    i18n: PropTypes.shape({
+      language: PropTypes.string.isRequired
+    }).isRequired
+  }
 
-Metadata.propTypes = {
-  title: PropTypes.string
-};
+  render() {
+    const { title, description, i18n } = this.props;
+    const htmlAttributes = {
+      lang: i18n.language
+    };
 
-export default Metadata;
+    return <Helmet htmlAttributes={ htmlAttributes }>
+      <title>{ title ? `Regexper - ${ title }` : 'Regexper' }</title>
+      { description && <meta name="description" content={ description } /> }
+    </Helmet>;
+  }
+}
+
+export { Metadata };
+export default withNamespaces()(Metadata);

src/components/Metadata/test.js

@@ -1,19 +1,26 @@
 import React from 'react';
 import { shallow } from 'enzyme';
 
-import Metadata from 'components/Metadata';
+import { Metadata } from 'components/Metadata';
+
+const commonProps = {
+  i18n: { language: 'test-lang' }
+};
 
 describe('Metadata', () => {
   test('rendering', () => {
     const component = shallow(
-      <Metadata />
+      <Metadata { ...commonProps } />
     );
     expect(component).toMatchSnapshot();
   });
 
-  test('rendering with a title', () => {
+  test('rendering with a title and description', () => {
     const component = shallow(
-      <Metadata title="Testing" />
+      <Metadata
+        title="Testing"
+        description="Test description"
+        { ...commonProps } />
     );
     expect(component).toMatchSnapshot();
   });