LibJS: Implement Intl.Locale.prototype.weekInfo property

Userland/Libraries/LibJS/Tests/builtins/Intl/Locale/Locale.prototype.weekInfo.js

@@ -0,0 +1,68 @@
+describe("errors", () => {
+    test("called on non-Locale object", () => {
+        expect(() => {
+            Intl.Locale.prototype.weekInfo;
+        }).toThrowWithMessage(TypeError, "Not an object of type Intl.Locale");
+    });
+});
+
+describe("normal behavior", () => {
+    test("basic functionality", () => {
+        const weekInfo = new Intl.Locale("en-US").weekInfo;
+
+        expect(weekInfo).toBeDefined();
+        expect(Object.getPrototypeOf(weekInfo)).toBe(Object.prototype);
+
+        expect(weekInfo.firstDay).toBeDefined();
+        expect(Object.getPrototypeOf(weekInfo.firstDay)).toBe(Number.prototype);
+        expect(weekInfo.firstDay).toBe(7);
+
+        expect(weekInfo.weekend).toBeDefined();
+        expect(Array.isArray(weekInfo.weekend)).toBeTrue();
+        expect(weekInfo.weekend).toEqual([6, 7]);
+
+        expect(weekInfo.minimalDays).toBeDefined();
+        expect(Object.getPrototypeOf(weekInfo.minimalDays)).toBe(Number.prototype);
+        expect(weekInfo.minimalDays).toBe(1);
+    });
+
+    test("regions with CLDR-specified firstDay", () => {
+        expect(new Intl.Locale("en-AG").weekInfo.firstDay).toBe(7);
+        expect(new Intl.Locale("en-SY").weekInfo.firstDay).toBe(6);
+        expect(new Intl.Locale("en-MV").weekInfo.firstDay).toBe(5);
+    });
+
+    test("firstDay falls back to default region 001", () => {
+        expect(new Intl.Locale("en-AC").weekInfo.firstDay).toBe(1);
+    });
+
+    test("regions with CLDR-specified weekend", () => {
+        expect(new Intl.Locale("en-AF").weekInfo.weekend).toEqual([4, 5]);
+        expect(new Intl.Locale("en-IN").weekInfo.weekend).toEqual([7]);
+        expect(new Intl.Locale("en-YE").weekInfo.weekend).toEqual([5, 6]);
+    });
+
+    test("weekend falls back to default region 001", () => {
+        expect(new Intl.Locale("en-AC").weekInfo.weekend).toEqual([6, 7]);
+    });
+
+    test("regions with CLDR-specified minimalDays", () => {
+        expect(new Intl.Locale("en-AD").weekInfo.minimalDays).toBe(4);
+        expect(new Intl.Locale("en-CZ").weekInfo.minimalDays).toBe(4);
+    });
+
+    test("minimalDays falls back to default region 001", () => {
+        expect(new Intl.Locale("en-AC").weekInfo.minimalDays).toBe(1);
+    });
+
+    test("likely regional subtags are added to locales without a region", () => {
+        const defaultRegion = new Intl.Locale("en-001").weekInfo;
+
+        // "en" expands to "en-US" when likely subtags are added.
+        const en = new Intl.Locale("en").weekInfo;
+        const enUS = new Intl.Locale("en-US").weekInfo;
+
+        expect(en).toEqual(enUS);
+        expect(en).not.toEqual(defaultRegion);
+    });
+});