Use browser default time and number formatting with polyfills if needed (#9481)

Co-authored-by: Paulus Schoutsen <balloob@gmail.com>

test/common/datetime/relative_time.ts

@@ -0,0 +1,115 @@
+import { assert } from "chai";
+
+import { relativeTime } from "../../../src/common/datetime/relative_time";
+import { NumberFormat, TimeFormat } from "../../../src/data/translation";
+
+describe("relativeTime", () => {
+  const locale = {
+    language: "en",
+    number_format: NumberFormat.language,
+    time_format: TimeFormat.language,
+  };
+
+  it("now", () => {
+    const now = new Date();
+    assert.strictEqual(relativeTime(now, locale, now), "now");
+    assert.strictEqual(relativeTime(now, locale, now, false), "0 seconds");
+  });
+
+  it("past_second", () => {
+    const inputdt = new Date("2021-02-03T11:22:00+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare),
+      "33 seconds ago"
+    );
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "33 seconds"
+    );
+  });
+
+  it("past_minute", () => {
+    const inputdt = new Date("2021-02-03T11:20:33+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "2 minutes ago");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "2 minutes"
+    );
+  });
+
+  it("past_hour", () => {
+    const inputdt = new Date("2021-02-03T09:22:33+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "2 hours ago");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "2 hours"
+    );
+  });
+
+  it("past_day", () => {
+    const inputdt = new Date("2021-02-01T11:22:33+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "2 days ago");
+    assert.strictEqual(relativeTime(inputdt, locale, compare, false), "2 days");
+  });
+
+  it("future_second", () => {
+    const inputdt = new Date("2021-02-03T11:22:55+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "in 22 seconds");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "22 seconds"
+    );
+  });
+
+  it("future_minute", () => {
+    const inputdt = new Date("2021-02-03T11:24:33+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "in 2 minutes");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "2 minutes"
+    );
+  });
+
+  it("future_hour", () => {
+    const inputdt = new Date("2021-02-03T13:22:33+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "in 2 hours");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "2 hours"
+    );
+  });
+
+  it("future_day", () => {
+    const inputdt = new Date("2021-02-05T11:22:33+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "in 2 days");
+    assert.strictEqual(relativeTime(inputdt, locale, compare, false), "2 days");
+  });
+
+  it("future_week", () => {
+    const inputdt = new Date("2021-03-24T11:22:33+00:00");
+    const compare = new Date("2021-03-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "in 3 weeks");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "3 weeks"
+    );
+  });
+
+  it("future_month", () => {
+    const inputdt = new Date("2021-03-03T11:22:33+00:00");
+    const compare = new Date("2021-02-03T11:22:33+00:00");
+    assert.strictEqual(relativeTime(inputdt, locale, compare), "next month");
+    assert.strictEqual(
+      relativeTime(inputdt, locale, compare, false),
+      "1 month"
+    );
+  });
+});