➕ jest

must be 26.x.y, 27 throws error
- callstack/react-native-testing-library#743
- https://stackoverflow.com/questions/68734508/typeerror-jest-a-transform-must-export-a-process-function-jest

package.json

@@ -11,7 +11,11 @@
     "eject": "expo eject",
     "commit": "cz",
     "lint": "eslint . --fix --ext ts,js,tsx,jsx",
-    "changelog": "npx gitmoji-changelog"
+    "changelog": "npx gitmoji-changelog",
+    "test": "jest",
+    "test:watch": "yarn test --watch",
+    "test:ci": "yarn test --coverage",
+    "test:badges": "yarn test:ci  && jest-coverage-badges --input coverage/coverage-summary.json --output __badges__"
   },
   "dependencies": {
     "@react-navigation/native": "^6.0.8",
@@ -42,12 +46,16 @@
     "@storybook/addon-ondevice-actions": "^5.3.23",
     "@storybook/addon-ondevice-knobs": "^5.3.25",
     "@storybook/react-native": "^5.3.25",
+    "@types/jest": "^27.4.0",
     "@types/react": "~17.0.21",
     "@types/react-native": "~0.64.12",
+    "@types/react-test-renderer": "17",
     "@types/styled-components-react-native": "^5.1.3",
     "@typescript-eslint/eslint-plugin": "^5.12.0",
     "@typescript-eslint/parser": "^5.12.0",
+    "babel-jest": "^27.5.1",
     "babel-loader": "^8.2.3",
+    "babel-polyfill": "^6.26.0",
     "commitizen": "^4.2.4",
     "commitlint-config-gitmoji": "^2.2.5",
     "cz-gitmoji": "0.0.7",
@@ -62,8 +70,12 @@
     "eslint-plugin-promise": "^5.2.0",
     "eslint-plugin-react": "^7.28.0",
     "husky": "^7.0.4",
+    "jest": "26.3.0",
+    "jest-coverage-badges": "^1.1.2",
+    "jest-expo": "^44.0.1",
     "lint-staged": "^12.3.4",
     "prettier": "2.5.1",
+    "react-test-renderer": "17",
     "typescript": "~4.3.5"
   },
   "private": true,