From 0c800344d23a222a7b17c30d5c6dd7b00fa5b90d Mon Sep 17 00:00:00 2001
From: Michael Varrieur <mvarrieur@users.noreply.github.com>
Date: Mon, 10 Oct 2022 10:26:02 -0400
Subject: [PATCH] Add custom selectUnit, use in relativeTime function (#14008)

---
 package.json                          |  1 -
 src/common/datetime/relative_time.ts  |  2 +-
 src/common/util/select-unit.ts        | 97 +++++++++++++++++++++++++++
 test/common/datetime/relative_time.ts |  8 +++
 yarn.lock                             | 10 ---
 5 files changed, 106 insertions(+), 12 deletions(-)
 create mode 100644 src/common/util/select-unit.ts

diff --git a/package.json b/package.json
index 987792155e..2db10f8920 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,6 @@
     "@formatjs/intl-numberformat": "^7.2.5",
     "@formatjs/intl-pluralrules": "^4.1.5",
     "@formatjs/intl-relativetimeformat": "^9.3.2",
-    "@formatjs/intl-utils": "^3.8.4",
     "@fullcalendar/common": "5.9.0",
     "@fullcalendar/core": "5.9.0",
     "@fullcalendar/daygrid": "5.9.0",
diff --git a/src/common/datetime/relative_time.ts b/src/common/datetime/relative_time.ts
index 4b517c608d..1adc6b7973 100644
--- a/src/common/datetime/relative_time.ts
+++ b/src/common/datetime/relative_time.ts
@@ -1,7 +1,7 @@
-import { selectUnit } from "@formatjs/intl-utils";
 import memoizeOne from "memoize-one";
 import { FrontendLocaleData } from "../../data/translation";
 import { polyfillsLoaded } from "../translations/localize";
+import { selectUnit } from "../util/select-unit";
 
 if (__BUILD__ === "latest" && polyfillsLoaded) {
   await polyfillsLoaded;
diff --git a/src/common/util/select-unit.ts b/src/common/util/select-unit.ts
new file mode 100644
index 0000000000..e18845cd44
--- /dev/null
+++ b/src/common/util/select-unit.ts
@@ -0,0 +1,97 @@
+export type Unit =
+  | "second"
+  | "minute"
+  | "hour"
+  | "day"
+  | "week"
+  | "month"
+  | "quarter"
+  | "year";
+
+const MS_PER_SECOND = 1e3;
+const SECS_PER_MIN = 60;
+const SECS_PER_HOUR = SECS_PER_MIN * 60;
+const SECS_PER_DAY = SECS_PER_HOUR * 24;
+const SECS_PER_WEEK = SECS_PER_DAY * 7;
+
+// Adapted from https://github.com/formatjs/formatjs/blob/186cef62f980ec66252ee232f438a42d0b51b9f9/packages/intl-utils/src/diff.ts
+export function selectUnit(
+  from: Date | number,
+  to: Date | number = Date.now(),
+  thresholds: Partial<Thresholds> = {}
+): { value: number; unit: Unit } {
+  const resolvedThresholds: Thresholds = {
+    ...DEFAULT_THRESHOLDS,
+    ...(thresholds || {}),
+  };
+
+  const secs = (+from - +to) / MS_PER_SECOND;
+  if (Math.abs(secs) < resolvedThresholds.second) {
+    return {
+      value: Math.round(secs),
+      unit: "second",
+    };
+  }
+
+  const mins = secs / SECS_PER_MIN;
+  if (Math.abs(mins) < resolvedThresholds.minute) {
+    return {
+      value: Math.round(mins),
+      unit: "minute",
+    };
+  }
+
+  const hours = secs / SECS_PER_HOUR;
+  if (Math.abs(hours) < resolvedThresholds.hour) {
+    return {
+      value: Math.round(hours),
+      unit: "hour",
+    };
+  }
+
+  const days = secs / SECS_PER_DAY;
+  if (Math.abs(days) < resolvedThresholds.day) {
+    return {
+      value: Math.round(days),
+      unit: "day",
+    };
+  }
+
+  const weeks = secs / SECS_PER_WEEK;
+  if (Math.abs(weeks) < resolvedThresholds.week) {
+    return {
+      value: Math.round(weeks),
+      unit: "week",
+    };
+  }
+
+  const fromDate = new Date(from);
+  const toDate = new Date(to);
+  const years = fromDate.getFullYear() - toDate.getFullYear();
+  const months = years * 12 + fromDate.getMonth() - toDate.getMonth();
+  if (Math.round(Math.abs(months)) < resolvedThresholds.month) {
+    return {
+      value: Math.round(months),
+      unit: "month",
+    };
+  }
+
+  return {
+    value: Math.round(years),
+    unit: "year",
+  };
+}
+
+type Thresholds = Record<
+  "second" | "minute" | "hour" | "day" | "week" | "month",
+  number
+>;
+
+export const DEFAULT_THRESHOLDS: Thresholds = {
+  second: 45, // seconds to minute
+  minute: 45, // minutes to hour
+  hour: 22, // hour to day
+  day: 5, // day to week
+  week: 4, // week to months
+  month: 11, // month to years
+};
diff --git a/test/common/datetime/relative_time.ts b/test/common/datetime/relative_time.ts
index 8bb0be7133..2e020e1ddc 100644
--- a/test/common/datetime/relative_time.ts
+++ b/test/common/datetime/relative_time.ts
@@ -112,4 +112,12 @@ describe("relativeTime", () => {
       "1 month"
     );
   });
+
+  it("handles a jump between years", () => {
+    const inputdt = new Date("2021-12-29");
+    const compare = new Date("2022-01-01");
+
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "3 days ago");
+    assert.strictEqual(relativeTime(inputdt, locale, compare, false), "3 days");
+  });
 });
diff --git a/yarn.lock b/yarn.lock
index 6c3e5251be..5b3051dcaf 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1679,15 +1679,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@formatjs/intl-utils@npm:^3.8.4":
-  version: 3.8.4
-  resolution: "@formatjs/intl-utils@npm:3.8.4"
-  dependencies:
-    emojis-list: ^3.0.0
-  checksum: e38a98d391ec68d8abc4bb1824426bd804dfb022ce61be004459faec69f7843ddb3733bae8d0dce4aafbfafad59cb10e67fc21d22d62f68d98251ce0bce8e704
-  languageName: node
-  linkType: hard
-
 "@fullcalendar/common@npm:5.9.0, @fullcalendar/common@npm:~5.9.0":
   version: 5.9.0
   resolution: "@fullcalendar/common@npm:5.9.0"
@@ -8982,7 +8973,6 @@ fsevents@^1.2.7:
     "@formatjs/intl-numberformat": ^7.2.5
     "@formatjs/intl-pluralrules": ^4.1.5
     "@formatjs/intl-relativetimeformat": ^9.3.2
-    "@formatjs/intl-utils": ^3.8.4
     "@fullcalendar/common": 5.9.0
     "@fullcalendar/core": 5.9.0
     "@fullcalendar/daygrid": 5.9.0