Setup enzyme for JSX tests

Signed-off-by: Marcos Loureiro <mloureiro.dev@gmail.com>

Author: mloureiro

.gitignore

@@ -3,3 +3,7 @@
 
 # TypeScript
 /dist
+
+# Jest
+.jest/
+/coverage/

jest.config.json

@@ -1,7 +1,11 @@
 {
+  "preset": "react-native",
   "transform": {
-    "^.+\\.(t|j)sx?$": "ts-jest"
+    "^.+\\.js$": "<rootDir>/node_modules/react-native/jest/preprocessor.js",
+    "^.+\\.tsx?$": "ts-jest"
   },
   "testRegex": "(/__tests__/.*|(\\.|/)(test|spec))\\.(jsx?|tsx?)$",
-  "moduleFileExtensions": ["ts", "tsx", "js", "jsx", "json", "node"]
+  "moduleFileExtensions": ["ts", "tsx", "js", "jsx", "json", "node"],
+  "modulePaths": ["<rootDir>"],
+  "setupFiles": ["<rootDir>/jest.setup.js"]
 }

jest.setup.js

@@ -0,0 +1,28 @@
+import { configure } from 'enzyme'
+import Adapter from 'enzyme-adapter-react-16'
+import { JSDOM } from 'jsdom'
+import 'react-native-mock-render/mock'
+
+function copyProps(src, target) {
+	Object.defineProperties(target, {
+		...Object.getOwnPropertyDescriptors(src),
+		...Object.getOwnPropertyDescriptors(target),
+	})
+}
+
+const jsdom = new JSDOM()
+const { window } = jsdom
+
+global.window = window
+global.document = window.document
+global.navigator = {
+	userAgent: 'node.js',
+}
+copyProps(window, global)
+
+configure({ adapter: new Adapter() })
+
+// react-native-jest-mock throws too many of warnings due to
+// unbridged new API methods/signature.
+// In order to reduce irrelevant spam, we mock these errors.
+console.error = message => message

package.json

@@ -29,16 +29,25 @@
 		"test:coverage": "yarn test --coverage --coverageReporters=text-lcov | coveralls"
 	},
 	"devDependencies": {
+		"@types/enzyme": "^3.1.15",
+		"@types/enzyme-adapter-react-16": "^1.0.3",
 		"@types/jest": "^23.3.12",
+		"@types/jsdom": "^12.2.1",
 		"@types/react": "^16.7.18",
 		"@types/react-native": "^0.57.27",
 		"coveralls": "^3.0.2",
+		"enzyme": "^3.8.0",
+		"enzyme-adapter-react-16": "^1.7.1",
 		"husky": "^1.3.1",
 		"jest": "^23.6.0",
+		"jest-fetch-mock": "^2.1.0",
+		"jsdom": "^13.1.0",
 		"lint-staged": "^8.1.0",
 		"prettier": "^1.15.3",
 		"react": "^16.7.0",
+		"react-dom": "^16.7.0",
 		"react-native": "^0.57.8",
+		"react-native-mock-render": "^0.1.2",
 		"ts-jest": "^23.10.5",
 		"tslint": "^5.12.1",
 		"tslint-config-prettier": "^1.17.0",