Merge pull request #177 from microsoft/users/t-xunguy/react-jest

Set up Unit Test for typescript/react

Author: xnkevinnguyen

jest.config.js

@@ -0,0 +1,28 @@
+module.exports = {
+    // The root of your source code, typically /src
+    // `<rootDir>` is a token Jest substitutes
+    roots: ["<rootDir>/src"],
+  
+    // Jest transformations -- this adds support for TypeScript
+    // using ts-jest
+    transform: {
+      '^.+\\.tsx?$': 'ts-jest',
+      ".+\\.(css|styl|less|sass|scss)$": "jest-transform-css"
+    },
+  
+    // Runs special logic, such as cleaning up components
+    // when using React Testing Library and adds special
+    // extended assertions to Jest
+    setupFilesAfterEnv: [
+      "@testing-library/jest-dom/extend-expect"
+    ],
+
+    // Test spec file resolution pattern
+    // Matches parent folder `__tests__` and filename
+    // should contain `test` or `spec`.
+    testRegex: "(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$",
+  
+    // Module file extensions for importing
+    moduleFileExtensions: ["ts", "tsx", "js", "jsx", "json", "node"],
+    
+  };