add constants mocking

frontend/app/common/__mocks__/constants.ts

@@ -0,0 +1,7 @@
+// @ts-ignore
+const mock: typeof import('@app/common/constants') = {
+  ...jest.requireActual('@app/common/constants'),
+  BASE_URL: 'https://demo.remark42.com/',
+};
+
+module.exports = mock;

frontend/app/common/__mocks__/settings.ts

@@ -0,0 +1,20 @@
+// @ts-ignore
+const mock: typeof import('@app/common/settings') = {
+  ...jest.requireActual('@app/common/settings'),
+  siteId: 'remark',
+  pageTitle: 'remark test',
+  url: 'https://remark42.com/test',
+  maxShownComments: 20,
+  token: 'abcd',
+  theme: 'light',
+  querySettings: {
+    site_id: 'remark',
+    page_title: 'remark test',
+    url: 'https://remark42.com/test',
+    max_shown_comments: 20,
+    token: 'abcd',
+    theme: 'light',
+  },
+};
+
+module.exports = mock;

frontend/app/testUtils/mockPostInfo.ts

@@ -0,0 +1,2 @@
+jest.mock('@app/common/settings');
+jest.mock('@app/common/constants');