EPMRPP-90262 || Setup tests for UI-kit and cover Button component

.eslintrc.cjs

@@ -2,17 +2,17 @@ module.exports = {
   root: true,
   env: {
     browser: true,
-    es2020: true
+    es2020: true,
   },
   extends: [
     'airbnb-typescript',
     'plugin:@typescript-eslint/recommended',
     'plugin:storybook/recommended',
-    "plugin:prettier/recommended",
-    "plugin:import/recommended",
+    'plugin:prettier/recommended',
+    'plugin:import/recommended',
     'plugin:react-hooks/recommended',
   ],
-  ignorePatterns: ['dist', '.eslintrc.cjs'],
+  ignorePatterns: ['dist', '.eslintrc.cjs', 'coverage', 'vitest.config.ts'],
   parser: '@typescript-eslint/parser',
   parserOptions: {
     ecmaVersion: 2020,
@@ -24,14 +24,17 @@ module.exports = {
       typescript: {
         alwaysTryTypes: true,
         project: ['./tsconfig.eslint.json'],
-      }
-    }
+      },
+    },
   },
   plugins: ['react-refresh', 'prettier', 'react'],
   rules: {
-    'react-refresh/only-export-components': ['warn', {
-      allowConstantExport: true
-    }],
-    "import/no-extraneous-dependencies": ["error", {"devDependencies": true}]
-  }
+    'react-refresh/only-export-components': [
+      'warn',
+      {
+        allowConstantExport: true,
+      },
+    ],
+    'import/no-extraneous-dependencies': ['error', { devDependencies: true }],
+  },
 };

.gitignore

@@ -24,3 +24,9 @@ dist-ssr
 *.njsproj
 *.sln
 *.sw?
+
+# Test coverage
+coverage
+.coverage
+coverage.json
+*.lcov

README.md

@@ -234,4 +234,27 @@ The CSS custom properties that come from DS are prefixed with `rp-ui-base` to av
 
 ### Testing
 
-To be provided.
+#### Testing Tools
+
+The project uses the following testing tools:
+- **Vitest**: Fast testing framework, compatible with Vite
+- **React Testing Library**: For testing React components with a focus on user interactions
+- **@testing-library/user-event**: For simulating user events in tests
+- **JSDOM**: For simulating a DOM environment in Node.js
+- **@vitest/coverage-v8**: For code coverage reporting
+
+#### Test Scripts
+
+Available npm scripts for testing:
+- `npm run test` - Run tests in watch mode
+- `npm run test:coverage` - Run tests with coverage report
+- `npm run test:ci` - Run tests once (for CI environments)
+- `npm run test:ui` - Run tests with UI interface
+
+#### Test Coverage
+
+The project maintains a minimum of 80% test coverage threshold for:
+- Statements
+- Branches
+- Functions
+- Lines