Jest fails with "Unexpected token *" on import statement

Some react-native libraries ship uncompiled ES6 code.

ES6 code needs to be compiled before it can be run by Jest.

The Jest doc about Testing React Native Apps includes a section about compiling dependencies that don't ship pre-compiled code.

You will need to tell Jest to compile react-navigation-tabs by whitelisting it in the transformIgnorePatterns option in your Jest config.

Example:

Changing the jest.config.js file into something like below, fixed the issue mentioned in OP.

But the "react-native-reanimated" module (which requires native integration, as described in another post) needs further work, and we should Mock modules with such native requirements...

module.exports = {  preset: 'react-native',  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],  transformIgnorePatterns: [    "node_modules/(?!(react-native"      + "|react-navigation-tabs"      + "|react-native-splash-screen"      + "|react-native-screens"      + "|react-native-reanimated"    + ")/)",  ],}

Note: the transformIgnorePatterns option (which is an array of Regular-Expressions) is originally meant to exclude files from being compiled, but using (?!(some-dir-name|another-name)) pattern (the (?!...), negative look-ahead), we do tell Jest to exclude anything in node_modules directory, except the names that we did specify.

As it has been said, some modules needs to be transpiled, & some don't.Here is a regex I use that work in a lot of projects

  "jest": {    "preset": "react-native",    "transformIgnorePatterns": [      "node_modules/(?!(jest-)?react-native|react-(native|universal|navigation)-(.*)|@react-native-community/(.*)|@react-navigation/(.*)|bs-platform|(@[a-zA-Z]+/)?(bs|reason|rescript)-(.*)+)"    ]  }

It's working for most common react native thing, & include also a specific package (here bs-platform) as an example, when isn't captured by previous patterns.

I had a similar issue on a React + Typescript app.

The first mistake I made was to define the jest.config.js as jest.config.ts

Running on Node v12.latest

Then the configuration that worked for me were the following:

// jest.config.jsmodule.exports = {  preset: "ts-jest",  testEnvironment: "node",  roots: ["./src"],  transform: { "\\.ts$": ["ts-jest"] },  testRegex: "(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$",  moduleFileExtensions: ["ts", "tsx", "js", "jsx", "json", "node"],  globals: {    "ts-jest": {      tsConfig: {        // allow js in typescript        allowJs: true,      },    },  },};

// tsconfig.json{  "compilerOptions": {    "target": "es5",    "lib": ["dom", "dom.iterable", "esnext"],    "allowJs": true,    "skipLibCheck": true,    "esModuleInterop": true,    "allowSyntheticDefaultImports": true,    "strict": true,    "forceConsistentCasingInFileNames": true,    "module": "esnext",    "moduleResolution": "node",    "resolveJsonModule": true,    "isolatedModules": true,    "noEmit": true,    "jsx": "react",    "baseUrl": "."  },  "include": ["src"],  "exclude": ["node_modules", "**/*.spec.ts"]}

// package.json"devDependencies": {    "@types/jest": "^26.0.5",    "jest": "^26.1.0",    "ts-jest": "^26.1.3"}