test for the platformstyle.js (#4168)

* Create platformstyle.test.js

* Update jest.config.js

* Update musicutils.test.js

resolving conflicts with the platformstyle.test.js

jest.config.js

@@ -2,4 +2,5 @@ module.exports = {
     testMatch: ['**/__tests__/**/*.test.js', '**/?(*.)+(spec|test).[jt]s?(x)'],
     clearMocks: true,
     moduleFileExtensions: ['js', 'json', 'node'],
+    testEnvironment: 'jsdom',
 };

js/utils/__tests__/musicutils.test.js

@@ -1,3 +1,5 @@
+const { TextEncoder } = require('util');
+global.TextEncoder = TextEncoder;
 global._ = jest.fn((str) => str);
 global.window = {
     btoa: jest.fn((str) => Buffer.from(str, "utf8").toString("base64"))

js/utils/__tests__/platformstyle.test.js

@@ -0,0 +1,19 @@
+describe('Platform Style Tests', () => {
+    beforeEach(() => {
+        const meta = document.createElement('meta');
+        meta.name = 'theme-color';
+        document.head.appendChild(meta);
+    });
+
+    afterEach(() => {
+        document.head.innerHTML = '';
+    });
+
+    test('should set the meta theme-color content based on platformColor', () => {
+        const platformColor = { header: '#ff0000' };
+        document.querySelector("meta[name=theme-color]").content = platformColor.header;
+
+        const meta = document.querySelector("meta[name=theme-color]");
+        expect(meta.content).toBe('#ff0000');
+    });
+});