feat(tests): add comprehensive unit tests for various components including AboutPage, CallPage, and MessagesPage

tests/frontend/LanguageSelector.test.js

@@ -0,0 +1,73 @@
+import { mount } from "@vue/test-utils";
+import { describe, it, expect, vi } from "vitest";
+import LanguageSelector from "@/components/LanguageSelector.vue";
+
+describe("LanguageSelector.vue", () => {
+    const mountLanguageSelector = (locale = "en") => {
+        return mount(LanguageSelector, {
+            global: {
+                mocks: {
+                    $t: (key) => key,
+                    $i18n: {
+                        locale: locale,
+                    },
+                },
+                stubs: {
+                    MaterialDesignIcon: true,
+                },
+            },
+        });
+    };
+
+    it("renders the language selector button", () => {
+        const wrapper = mountLanguageSelector();
+        expect(wrapper.find("button").exists()).toBe(true);
+    });
+
+    it("toggles the dropdown when the button is clicked", async () => {
+        const wrapper = mountLanguageSelector();
+        const button = wrapper.find("button");
+
+        expect(wrapper.find(".absolute").exists()).toBe(false);
+
+        await button.trigger("click");
+        expect(wrapper.find(".absolute").exists()).toBe(true);
+
+        await button.trigger("click");
+        expect(wrapper.find(".absolute").exists()).toBe(false);
+    });
+
+    it("lists all available languages in the dropdown", async () => {
+        const wrapper = mountLanguageSelector();
+        await wrapper.find("button").trigger("click");
+
+        const languageButtons = wrapper.findAll(".absolute button");
+        expect(languageButtons).toHaveLength(3);
+        expect(languageButtons[0].text()).toContain("English");
+        expect(languageButtons[1].text()).toContain("Deutsch");
+        expect(languageButtons[2].text()).toContain("Русский");
+    });
+
+    it("emits language-change when a different language is selected", async () => {
+        const wrapper = mountLanguageSelector("en");
+        await wrapper.find("button").trigger("click");
+
+        const deButton = wrapper.findAll(".absolute button")[1];
+        await deButton.trigger("click");
+
+        expect(wrapper.emitted("language-change")).toBeTruthy();
+        expect(wrapper.emitted("language-change")[0]).toEqual(["de"]);
+        expect(wrapper.find(".absolute").exists()).toBe(false);
+    });
+
+    it("does not emit language-change when the current language is selected", async () => {
+        const wrapper = mountLanguageSelector("en");
+        await wrapper.find("button").trigger("click");
+
+        const enButton = wrapper.findAll(".absolute button")[0];
+        await enButton.trigger("click");
+
+        expect(wrapper.emitted("language-change")).toBeFalsy();
+        expect(wrapper.find(".absolute").exists()).toBe(false);
+    });
+});