adding monkeytype

frontend/__tests__/utils/date-and-time.spec.ts

@@ -0,0 +1,88 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import * as DateAndTime from "../../src/ts/utils/date-and-time";
+
+describe("date-and-time", () => {
+  const testCases = [
+    { locale: "en-US", firstDayOfWeek: 0 },
+    { locale: "en", firstDayOfWeek: 0 },
+    { locale: "de-DE", firstDayOfWeek: 1 },
+    { locale: "en-DE", firstDayOfWeek: 1, firefoxFirstDayOfWeek: 0 },
+    { locale: "de-AT", firstDayOfWeek: 1 },
+    { locale: "ps-AF", firstDayOfWeek: 6, firefoxFirstDayOfWeek: 0 },
+    { locale: "de-unknown", firstDayOfWeek: 1 },
+    { locale: "xx-yy", firstDayOfWeek: 1, firefoxFirstDayOfWeek: 0 },
+  ];
+
+  describe("getFirstDayOfTheWeek", () => {
+    const languageMock = vi.spyOn(window.navigator, "language", "get");
+    const localeMock = vi.spyOn(Intl, "Locale");
+
+    beforeEach(() => {
+      languageMock.mockClear();
+      localeMock.mockClear();
+    });
+
+    it("fallback to sunday for missing language", () => {
+      //GIVEN
+      languageMock.mockReturnValue(null as any);
+
+      //WHEN / THEN
+      expect(DateAndTime.getFirstDayOfTheWeek()).toEqual(0);
+    });
+
+    describe("with weekInfo", () => {
+      it.for(testCases)(`$locale`, ({ locale, firstDayOfWeek }) => {
+        //GIVEN
+        languageMock.mockReturnValue(locale);
+        localeMock.mockImplementation(function (this: any) {
+          return { weekInfo: { firstDay: firstDayOfWeek } } as any;
+        });
+
+        //WHEN/THEN
+        expect(DateAndTime.getFirstDayOfTheWeek()).toEqual(firstDayOfWeek);
+      });
+    });
+
+    describe("with getWeekInfo", () => {
+      it("with getWeekInfo on monday", () => {
+        languageMock.mockReturnValue("en-US");
+        localeMock.mockImplementationOnce(function (this: any) {
+          return { getWeekInfo: () => ({ firstDay: 1 }) } as any;
+        });
+
+        //WHEN/THEN
+        expect(DateAndTime.getFirstDayOfTheWeek()).toEqual(1);
+      });
+      it("with getWeekInfo on sunday", () => {
+        languageMock.mockReturnValue("en-US");
+        localeMock.mockImplementationOnce(function (this: any) {
+          return { getWeekInfo: () => ({ firstDay: 7 }) } as any;
+        });
+
+        //WHEN/THEN
+        expect(DateAndTime.getFirstDayOfTheWeek()).toEqual(0);
+      });
+    });
+
+    describe("without weekInfo (firefox)", () => {
+      beforeEach(() => {
+        localeMock.mockImplementation(function (this: any) {
+          return {} as any;
+        });
+      });
+
+      it.for(testCases)(
+        `$locale`,
+        ({ locale, firstDayOfWeek, firefoxFirstDayOfWeek }) => {
+          //GIVEN
+          languageMock.mockReturnValue(locale);
+
+          //WHEN/THEN
+          expect(DateAndTime.getFirstDayOfTheWeek()).toEqual(
+            firefoxFirstDayOfWeek ?? firstDayOfWeek,
+          );
+        },
+      );
+    });
+  });
+});