feat: enable the use of TypeScript in this repo (#604)

* feat: enable Typescript in this repo

* refactor: rename studio-header files to .ts[x]

* chore: fix minor type warnings

* chore: add types for frontend-platform

* chore: fix type issues

* chore: update name of suppressed lint check

src/desktop-header/DesktopHeader.jsx

@@ -22,7 +22,7 @@ import messages from '../Header.messages';
 import { CaretIcon } from '../Icons';
 
 class DesktopHeader extends React.Component {
-  constructor(props) { // eslint-disable-line no-useless-constructor
+  constructor(props) { // eslint-disable-line @typescript-eslint/no-useless-constructor
     super(props);
   }
 

src/frontend-platform.d.ts

@@ -0,0 +1,41 @@
+// frontend-platform currently doesn't provide types... do it ourselves for i18n module at least.
+// We can remove this in the future when we migrate to frontend-shell, or when frontend-platform gets types
+// (whichever comes first).
+
+declare module '@edx/frontend-platform/i18n' {
+  // eslint-disable-next-line import/no-extraneous-dependencies
+  import { injectIntl as _injectIntl } from 'react-intl';
+  /** @deprecated Use useIntl() hook instead. */
+  export const injectIntl: typeof _injectIntl;
+  /** @deprecated Use useIntl() hook instead. */
+  export const intlShape: any;
+
+  // eslint-disable-next-line import/no-extraneous-dependencies
+  export {
+    createIntl,
+    FormattedDate,
+    FormattedTime,
+    FormattedRelativeTime,
+    FormattedNumber,
+    FormattedPlural,
+    FormattedMessage,
+    defineMessages,
+    IntlProvider,
+    useIntl,
+  } from 'react-intl';
+
+  // Other exports from the i18n module:
+  export const configure: any;
+  export const getPrimaryLanguageSubtag: (code: string) => string;
+  export const getLocale: (locale?: string) => string;
+  export const getMessages: any;
+  export const isRtl: (locale?: string) => boolean;
+  export const handleRtl: any;
+  export const mergeMessages: any;
+  export const LOCALE_CHANGED: any;
+  export const LOCALE_TOPIC: any;
+  export const getCountryList: any;
+  export const getCountryMessages: any;
+  export const getLanguageList: any;
+  export const getLanguageMessages: any;
+}

src/mobile-header/MobileHeader.jsx

@@ -21,7 +21,7 @@ import messages from '../Header.messages';
 import { MenuIcon } from '../Icons';
 
 class MobileHeader extends React.Component {
-  constructor(props) { // eslint-disable-line no-useless-constructor
+  constructor(props) { // eslint-disable-line @typescript-eslint/no-useless-constructor
     super(props);
   }
 

src/studio-header/BrandNav.test.tsx

@@ -34,7 +34,7 @@ describe('BrandNav Component', () => {
   it('displays a link that navigates to studioBaseUrl', () => {
     render(<RootWrapper />);
 
-    const link = screen.getByRole('link');
+    const link = screen.getByRole('link') as HTMLAnchorElement;
     expect(link.href).toBe(studioBaseUrl);
   });
 });

src/studio-header/CourseLockUp.test.tsx

@@ -16,7 +16,7 @@ const mockProps = {
 
 const RootWrapper = (props) => (
   <MemoryRouter>
-    <IntlProvider locale="en" messages={messages}>
+    <IntlProvider locale="en" messages={{}}>
       <CourseLockUp {...props} />
     </IntlProvider>
   </MemoryRouter>
@@ -52,7 +52,8 @@ describe('CourseLockUp Component', () => {
   it('navigates to an absolute URL when clicked', () => {
     render(<RootWrapper {...mockProps} />);
 
-    const link = screen.getByTestId('course-lock-up-block');
+    // FIXME: don't use testId - https://testing-library.com/docs/queries/about#priority
+    const link = screen.getByTestId('course-lock-up-block') as HTMLAnchorElement;
     expect(link.href).toBe(mockProps.outlineLink);
   });
 });

src/studio-header/HeaderBody.test.tsx

@@ -35,7 +35,7 @@ const defaultProps = {
 
 const RootWrapper = (props) => (
   <MemoryRouter>
-    <IntlProvider locale="en" messages={messages}>
+    <IntlProvider locale="en" messages={{}}>
       <HeaderBody {...props} />
     </IntlProvider>
   </MemoryRouter>

src/studio-header/HeaderBody.tsx

@@ -135,6 +135,7 @@ const HeaderBody = ({
               logoutUrl,
               authenticatedUserAvatar,
               isAdmin,
+              isMobile,
             }}
           />
         </Nav>

src/studio-header/MobileHeader.tsx

@@ -13,6 +13,7 @@ const MobileHeader = ({
 
   return (
     <>
+      {/* @ts-expect-error The type of 'props' is any until we convert from propTypes to TypeScript interface/types */}
       <HeaderBody
         {...props}
         isMobile

src/studio-header/StudioHeader.test.tsx

@@ -26,7 +26,7 @@ let screenWidth = 1280;
 
 const RootWrapper = ({
   ...props
-}) => {
+}: React.ComponentProps<typeof StudioHeader>) => {
   const appContextValue = useMemo(() => ({
     authenticatedUser: currentUser,
     config: {
@@ -55,7 +55,7 @@ const RootWrapper = ({
   );
 };
 
-const props = {
+const props: React.ComponentProps<typeof StudioHeader> = {
   number: '123',
   org: 'Ed',
   title: 'test',
@@ -74,6 +74,10 @@ const props = {
   outlineLink: 'tEsTLInK',
   searchButtonAction: null,
   isNewHomePage: true,
+  // These default values shouldn't be needed but typescript is confused by propTypes; can remove after converting
+  // from propTypes to TypeScript:
+  containerProps: {},
+  isHiddenMainMenu: false,
 };
 
 describe('Header', () => {

src/studio-header/StudioHeader.tsx

@@ -19,6 +19,7 @@ const StudioHeader = ({
   number, org, title, containerProps, isHiddenMainMenu, mainMenuDropdowns,
   outlineLink, searchButtonAction, isNewHomePage,
 }) => {
+  // @ts-expect-error - frontend-platform doesn't yet have type information :/
   const { authenticatedUser, config } = useContext(AppContext);
   const props = {
     logo: config.LOGO_URL,