Add various js build configs

jest.config.js

@@ -1,11 +1,12 @@
 module.exports = {
   clearMocks: true,
-  moduleFileExtensions: ['js', 'ts'],
+  moduleFileExtensions: ['js', 'ts', 'json'],
   testEnvironment: 'node',
   testMatch: ['**/*.test.ts'],
   testRunner: 'jest-circus/runner',
   transform: {
     '^.+\\.ts$': 'ts-jest'
   },
-  verbose: true
-}
+  verbose: true,
+  setupFilesAfterEnv: ['./jest.setup.js']
+}