[test] Refactor translation loading test to use async/await and mock fetch

Author: KristjanESPERANTO

tests/unit/classes/translator_spec.js

@@ -198,28 +198,32 @@ describe("Translator", () => {
 			});
 		});
 
-		it("should not load translations, if module fallback exists", () => {
-			return new Promise((done) => {
-				const dom = new JSDOM(`<script>var Log = {log: () => {}};</script><script src="file://${path.join(__dirname, "..", "..", "..", "js", "translator.js")}">`, { runScripts: "dangerously", resources: "usable" });
-				dom.window.onload = async () => {
-					const { Translator, XMLHttpRequest } = dom.window;
-					const file = "translation_test.json";
+		it("should not load translations, if module fallback exists", async () => {
+			const dom = new JSDOM(`<script>var Log = {log: () => {}};</script><script src="file://${path.join(__dirname, "..", "..", "..", "js", "translator.js")}">`, { runScripts: "dangerously", resources: "usable" });
+			await new Promise((resolve) => dom.window.onload = resolve);
 
-					XMLHttpRequest.prototype.send = () => {
-						throw new Error("Shouldn't load files");
-					};
+			const { Translator } = dom.window;
+			const file = "translation_test.json";
 
-					Translator.translationsFallback[mmm.name] = {
-						Hello: "Hallo"
-					};
+			// Mock fetch to ensure no actual requests are made
+			const originalFetch = dom.window.fetch;
+			dom.window.fetch = jest.fn(() => {
+				throw new Error("Shouldn't load files");
+			});
 
-					await Translator.load(mmm, file, false);
-					expect(Translator.translations[mmm.name]).toBeUndefined();
-					expect(Translator.translationsFallback[mmm.name]).toEqual({
-						Hello: "Hallo"
-					});
-					done();
-				};
+			// Restore the original fetch after the test
+			afterAll(() => {
+				dom.window.fetch = originalFetch;
+			});
+
+			Translator.translationsFallback[mmm.name] = {
+				Hello: "Hallo"
+			};
+
+			await Translator.load(mmm, file, false);
+			expect(Translator.translations[mmm.name]).toBeUndefined();
+			expect(Translator.translationsFallback[mmm.name]).toEqual({
+				Hello: "Hallo"
 			});
 		});
 	});