chore: course banner hook tests

src/setupTest.jsx

@@ -18,19 +18,21 @@ jest.mock('react', () => ({
 jest.mock('@edx/frontend-platform/i18n', () => {
   const i18n = jest.requireActual('@edx/frontend-platform/i18n');
   const PropTypes = jest.requireActual('prop-types');
+  const formatMessage = jest.fn((msg) => (
+    <formatMessage
+      msg={msg.defaultMessage}
+      {...(msg.values && { values: msg.values })}
+    />
+  ));
+  const formatDate = jest.fn().mockName('useIntl.formatDate');
   return {
     ...i18n,
     intlShape: PropTypes.shape({
       formatMessage: PropTypes.func,
     }),
     useIntl: () => ({
-      formatMessage: (msg) => (
-        <formatMessage
-          msg={msg.defaultMessage}
-          {...(msg.values && { values: msg.values })}
-        />
-      ),
-      formatDate: jest.fn().mockName('useIntl.formatDate'),
+      formatMessage,
+      formatDate,
     }),
     IntlProvider: () => 'IntlProvider',
     defineMessages: m => m,