Initial commit

packages/i18n/tests/features/translation.test.ts

@@ -0,0 +1,127 @@
+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.ts";
+
+describe("new I18n(...)", () => {
+	it("throws error when passed messageUrlTemplate w/o :locale, :namespace placeholders", () => {
+		assert.throws(
+			() =>
+				withFixture("base", {
+					messagesUrlTemplate: new URL(
+						"../some/path",
+						import.meta.url,
+					),
+				}),
+			{
+				message:
+					'messagesUrlTemplate is missing required placeholders [":locale", ":namespace"]',
+			},
+		);
+
+		assert.throws(
+			() =>
+				withFixture("base", {
+					messagesUrlTemplate: new URL(
+						"../some/path/:namespace",
+						import.meta.url,
+					),
+				}),
+			{
+				message:
+					'messagesUrlTemplate is missing required placeholders [":locale"]',
+			},
+		);
+	});
+
+	it("throws error when passed empty array of supportedLocales", () => {
+		assert.throws(
+			() =>
+				withFixture("base", {
+					supportedLocales: [],
+				}),
+			{
+				message:
+					"supportedLocales is empty and no locales would be supported",
+			},
+		);
+	});
+
+	it("throws error when passed locale strings that don't conform to RFC 5646", () => {
+		const invalidLocales = ["en_US", "zh-CN-UTF-8", "en-GB@euro"];
+		assert.throws(
+			() =>
+				withFixture("base", {
+					supportedLocales: ["fr-Latn-FR", ...invalidLocales],
+				}),
+			{
+				message: `supportedLocales contains invalid RFC 5646 locale strings ["en_US","zh-CN-UTF-8","en-GB@euro"]`,
+			},
+		);
+	});
+});
+
+describe("i18n.loadMessages(...)", () => {
+	let i18n: I18n<Fixtures["base"]>;
+	beforeEach(() => {
+		i18n = withFixture("base");
+	});
+
+	it("throws error when requesting namespaces that weren't declared", async () => {
+		await assert.rejects(
+			i18n.loadMessages({
+				locale: "en",
+				// @ts-ignore
+				namespaces: ["doesnt-exist", "neither-does-this"],
+			}),
+			{
+				message:
+					'attempted to load messages from undeclared namespaces ["doesnt-exist", "neither-does-this"] ' +
+					"(did you declare them in the I18n constructor?)",
+			},
+		);
+	});
+
+	it("throws error when requesting locales that weren't declared", async () => {
+		await assert.rejects(
+			i18n.loadMessages({
+				locale: "de",
+				namespaces: ["drama"],
+			}),
+			{
+				message:
+					'no declared locale matches requested locale of "de-Latn-DE" (maximized from "de")',
+			},
+		);
+	});
+});
+
+describe("t(...)", () => {
+	let i18n: I18n<Fixtures["base"]>;
+	beforeEach(() => {
+		i18n = withFixture("base");
+	});
+
+	it("correctly translates common messages", async () => {
+		const t = await i18n.loadMessages({ locale: "fr" });
+		assert.equal(t("denial"), "Je ne l'ai pas frappée. Je ne l'ai pas.");
+	});
+
+	it("correctly substitutes placeholders in translations", async () => {
+		const t = await i18n.loadMessages({ locale: "fr" });
+		assert.equal(t("oh hai", { name: "Mark" }), "Oh salut, Mark !");
+	});
+
+	it("correctly translates messages with nested keys", async () => {
+		const t = await i18n.loadMessages({ locale: "fr" });
+		assert.equal(t("flower shop.doggy"), "Salut toutou !");
+	});
+
+	it("correctly translates namespaced messages", async () => {
+		const t = await i18n.loadMessages({
+			locale: "fr",
+			namespaces: ["drama"],
+		});
+		assert.equal(t("drama:tearing me apart"), "Tu me déchires, Lisa !");
+	});
+});