chore: Move to Typescript (#2783)

This PR moves the entire project to Typescript. Due to the ~1000 ignores this will lead to a messy codebase for a while, but the churn is worth it – all of those ignore comments are places that were never type-safe previously.

closes #1282

app/utils/dates.ts

@@ -0,0 +1,64 @@
+import {
+  isToday,
+  isYesterday,
+  differenceInCalendarWeeks,
+  differenceInCalendarMonths,
+  differenceInCalendarYears,
+  format as formatDate,
+} from "date-fns";
+import { TFunction } from "react-i18next";
+import { dateLocale } from "~/utils/i18n";
+
+export function dateToHeading(
+  dateTime: string,
+  t: TFunction,
+  userLocale: string | null | undefined
+) {
+  const date = Date.parse(dateTime);
+  const now = new Date();
+  const locale = dateLocale(userLocale);
+
+  if (isToday(date)) {
+    return t("Today");
+  }
+
+  if (isYesterday(date)) {
+    return t("Yesterday");
+  }
+
+  // If the current calendar week but not today or yesterday then return the day
+  // of the week as a string. We use the LocaleTime component here to gain
+  // async bundle loading of languages
+  const weekDiff = differenceInCalendarWeeks(now, date);
+
+  if (weekDiff === 0) {
+    return formatDate(Date.parse(dateTime), "iiii", {
+      locale,
+    });
+  }
+
+  if (weekDiff === 1) {
+    return t("Last week");
+  }
+
+  const monthDiff = differenceInCalendarMonths(now, date);
+
+  if (monthDiff === 0) {
+    return t("This month");
+  }
+
+  if (monthDiff === 1) {
+    return t("Last month");
+  }
+
+  const yearDiff = differenceInCalendarYears(now, date);
+
+  if (yearDiff === 0) {
+    return t("This year");
+  }
+
+  // If older than the current calendar year then just print the year e.g 2020
+  return formatDate(Date.parse(dateTime), "y", {
+    locale,
+  });
+}