feat(test): ensure frontend translations are valid JSON

src/services/i18n.spec.ts

@@ -0,0 +1,19 @@
+import { describe, expect, it } from "vitest";
+import * as i18n from "./i18n.js";
+import path from "path";
+import fs from "fs";
+
+describe("i18n", () => {
+    it("frontend translations are valid JSON", () => {
+        const translationDir = "src/public/translations";
+        const locales = i18n.getLocales();
+
+        for (const locale of locales) {
+            const translationPath = path.join(translationDir, locale.id, "translation.json");
+            const translationFile = fs.readFileSync(translationPath, { encoding: "utf-8" });
+            expect(() => {
+                JSON.parse(translationFile);
+            }, `JSON error while parsing locale '${locale.id}' at "${translationPath}"`).not.toThrow();
+        }
+    });
+});