add tests to project

package.json

@@ -7,7 +7,8 @@
     "android": "expo start --android",
     "ios": "expo start --ios",
     "web": "expo start --web",
-    "lint": "eslint --ext .js,.jsx,.ts,.tsx"
+    "lint": "eslint --ext .js,.jsx,.ts,.tsx",
+    "test": "jest"
   },
   "dependencies": {
     "@react-native/metro-config": "^0.73.3",
@@ -22,6 +23,8 @@
   "devDependencies": {
     "@babel/core": "^7.20.0",
     "@expo/webpack-config": "^19.0.0",
+    "@testing-library/react-native": "^12.4.3",
+    "@types/jest": "^29.5.11",
     "@types/react": "~18.2.14",
     "eslint": "^8.54.0",
     "eslint-config-universe": "^12.0.0",
@@ -30,10 +33,15 @@
     "eslint-plugin-react-hooks": "^4.6.0",
     "eslint-plugin-react-native": "^4.1.0",
     "eslint-plugin-simple-import-sort": "^10.0.0",
+    "jest": "^29.7.0",
     "prettier": "^3.1.0",
     "react-dom": "18.2.0",
     "react-native-web": "~0.19.6",
+    "react-test-renderer": "^18.2.0",
     "typescript": "^5.1.3"
   },
+  "jest": {
+    "preset": "@testing-library/react-native"
+  },
   "private": true
 }

src/components/Button/PrimaryButton.test.tsx

@@ -0,0 +1,20 @@
+import { fireEvent, render, screen } from '@testing-library/react-native';
+
+import PrimaryButton from './PrimaryButton';
+
+const onPress = jest.fn();
+
+describe('PrimaryButton component tests', () => {
+  it('properly renders button with provided title', () => {
+    render(<PrimaryButton title="test" onPress={onPress} />);
+
+    expect(screen.getByText('test')).toBeDefined();
+  });
+  it('calls provieded onPress method', () => {
+    render(<PrimaryButton title="test" onPress={onPress} />);
+
+    fireEvent(screen.getByText('test'), 'press');
+
+    expect(onPress).toHaveBeenCalledTimes(1);
+  });
+});

src/components/Button/index.ts

@@ -0,0 +1 @@
+export { default as PrimaryButton } from './PrimaryButton';