LibJS: Implement Intl.ListFormat.prototype.resolvedOptions

Userland/Libraries/LibJS/Tests/builtins/Intl/ListFormat/ListFormat.prototype.resolvedOptions.js

@@ -0,0 +1,38 @@
+describe("correct behavior", () => {
+    test("length is 0", () => {
+        expect(Intl.ListFormat.prototype.resolvedOptions).toHaveLength(0);
+    });
+
+    test("all valid types", () => {
+        ["conjunction", "disjunction", "unit"].forEach(type => {
+            const en = new Intl.ListFormat("en", { type: type });
+            expect(en.resolvedOptions()).toEqual({
+                locale: "en",
+                type: type,
+                style: "long",
+            });
+        });
+    });
+
+    test("all valid styles", () => {
+        ["long", "short", "narrow"].forEach(style => {
+            const en = new Intl.ListFormat("en", { style: style });
+            expect(en.resolvedOptions()).toEqual({
+                locale: "en",
+                type: "conjunction",
+                style: style,
+            });
+        });
+    });
+
+    test("locales with extensions", () => {
+        const en = new Intl.ListFormat("en-t-en");
+        expect(en.resolvedOptions().locale).toBe("en");
+
+        const es419 = new Intl.ListFormat("es-419-u-1k-aaa");
+        expect(es419.resolvedOptions().locale).toBe("es-419");
+
+        const zhHant = new Intl.ListFormat(["zh-Hant-x-aaa"]);
+        expect(zhHant.resolvedOptions().locale).toBe("zh-Hant");
+    });
+});