Initial commit

packages/i18n/tests/features/locale-maximization.ts

@@ -0,0 +1,61 @@
+import assert from "node:assert/strict";
+import { beforeEach, describe, it } from "node:test";
+import type I18n from "@websnacksjs/i18n";
+import { type Fixtures, withFixture } from "../fixtures.js";
+
+describe("i18n.supportedLocales()", () => {
+	let i18n: I18n<Fixtures["base"]>;
+	beforeEach(() => {
+		i18n = withFixture("base", {
+			supportedLocales: ["en", "fr", "fr-Arab"],
+		});
+	});
+
+	it("returns maximized locales for all declared, supported locales", () => {
+		assert.deepEqual(i18n.supportedLocales(), [
+			"en-Latn-US",
+			"fr-Latn-FR",
+			"fr-Arab-FR",
+		]);
+	});
+});
+
+describe("i18n.loadMessages(...)", () => {
+	let i18n: I18n<Fixtures["base"]>;
+	beforeEach(() => {
+		i18n = withFixture("base");
+	});
+
+	it("guesses region of locales w/o region tags", async () => {
+		const t = await i18n.loadMessages({
+			locale: "fr-Latn",
+		});
+		assert.equal(t.locale(), "fr-Latn-FR");
+	});
+
+	it("guesses script of locales w/ region tags", async () => {
+		const t = await i18n.loadMessages({
+			locale: "fr-FR",
+		});
+		assert.equal(t.locale(), "fr-Latn-FR");
+	});
+
+	it("guesses script & region of bare language locales", async () => {
+		const t = await i18n.loadMessages({
+			locale: "fr",
+		});
+		assert.equal(t.locale(), "fr-Latn-FR");
+	});
+
+	it("does NOT fallback to bare language locales", async () => {
+		await assert.rejects(
+			i18n.loadMessages({
+				locale: "en-Arab",
+			}),
+			{
+				message:
+					'no declared locale matches requested locale of "en-Arab-US" (maximized from "en-Arab")',
+			},
+		);
+	});
+});