refactor: monorepo setup with lerna (#243)

packages/app/jest.config.js

@@ -0,0 +1,18 @@
+const { pathsToModuleNameMapper } = require('ts-jest');
+
+const { compilerOptions } = require('./tsconfig.base');
+
+module.exports = {
+  preset: 'ts-jest',
+  transform: {
+    '\\.[jt]sx?$': ['ts-jest', { tsConfig: 'tsconfig.dev.json' }],
+    '^.+\\.svg$': './test/fileTransformer',
+  },
+  moduleNameMapper: {
+    ...pathsToModuleNameMapper(compilerOptions.paths, { prefix: '<rootDir>/' }),
+    '\\.(css|less)$': '<rootDir>/src/__mocks__/styleMock.ts',
+  },
+  setupFiles: ['./test/setupEnv.js'],
+  testRegex: '\\.spec\\.tsx?$',
+  snapshotSerializers: ['@emotion/jest/serializer'],
+};