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

Author: bradenmacdonald

.github/workflows/ci.yml

@@ -24,6 +24,8 @@ jobs:
       run: make validate-no-uncommitted-package-lock-changes
     - name: Lint
       run: npm run lint
+    - name: Type check
+      run: npm run types
     - name: Test
       run: npm run test
     - name: Build

.github/workflows/release.yml

@@ -25,6 +25,8 @@ jobs:
       run: make validate-no-uncommitted-package-lock-changes
     - name: Lint
       run: npm run lint
+    - name: Type check
+      run: npm run types
     - name: Test
       run: npm run test
     - name: i18n_extract

package.json

@@ -13,7 +13,8 @@
     "lint:fix": "fedx-scripts eslint --fix --ext .js --ext .jsx .",
     "snapshot": "fedx-scripts jest --updateSnapshot",
     "start": "fedx-scripts webpack-dev-server --progress",
-    "test": "fedx-scripts jest --coverage"
+    "test": "fedx-scripts jest --coverage",
+    "types": "tsc --noEmit"
   },
   "files": [
     "/dist"

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.jsx renamed to 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/BrandNav.jsx renamed to src/studio-header/BrandNav.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);
   });
 });