feat: require JSDoc in new api (#50429)

Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>

api/src/utils/normalize.ts

@@ -9,6 +9,12 @@ type NoNullProperties<T> = {
   [P in keyof T]: NullToUndefined<T[P]>;
 };
 
+/**
+ * Converts a Twitter handle or URL to a URL.
+ *
+ * @param handleOrUrl Twitter handle or URL.
+ * @returns Twitter URL.
+ */
 export const normalizeTwitter = (
   handleOrUrl: string | null
 ): string | undefined => {
@@ -23,6 +29,12 @@ export const normalizeTwitter = (
   return url ?? handleOrUrl;
 };
 
+/**
+ * Ensure that the user's profile UI settings are valid.
+ *
+ * @param maybeProfileUI A null or the user's profile UI settings.
+ * @returns The input with nulls removed or a default value if there is no input.
+ */
 export const normalizeProfileUI = (
   maybeProfileUI: ProfileUI | null
 ): NoNullProperties<ProfileUI> => {
@@ -42,6 +54,12 @@ export const normalizeProfileUI = (
       };
 };
 
+/**
+ * Remove all the null properties from an object.
+ *
+ * @param obj Any object.
+ * @returns The input with nulls removed.
+ */
 export const removeNulls = <T extends Record<string, unknown>>(
   obj: T
 ): NoNullProperties<T> =>
@@ -65,6 +83,12 @@ type NormalizedChallenge = {
   solution?: string;
 };
 
+/**
+ * Remove all the null properties from a CompletedChallenge array.
+ *
+ * @param completedChallenges The CompletedChallenge array.
+ * @returns The input with nulls removed.
+ */
 export const normalizeChallenges = (
   completedChallenges: CompletedChallenge[]
 ): NormalizedChallenge[] => {