Add JS tests. Cleanup code and add github workflow to test.

jest.config.js

@@ -0,0 +1,30 @@
+module.exports = {
+  // The root of your source code, typically /src
+  // `<rootDir>` is a token Jest substitutes
+  roots: ['<rootDir>/src'],
+
+  // Jest transformations -- this adds support for TypeScript
+  // using ts-jest
+  transform: {
+    '^.+\\.tsx?$': 'ts-jest',
+  },
+
+  // Runs special logic, such as cleaning up components
+  // when using React Testing Library and adds special
+  // extended assertions to Jest
+  setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
+
+  // Test spec file resolution pattern
+  // Matches parent folder `__tests__` and filename
+  // should contain `test` or `spec`.
+  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',
+
+  // Module file extensions for importing
+  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
+
+  moduleNameMapper: {
+    '^.+\\.(css|scss)$': 'identity-obj-proxy',
+    '\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$':
+      '<rootDir>/fileMocks.js',
+  },
+};