Jest + Typescript Unable to Import Library (tiny-secp256k1)

Question

I am currently using the npm package tiny-secp256k1.

It provides non-default exports of many functions (with type declaration).

No matter how I try to import it, running my test suite. Jest throws:

    /pathToProject/node_modules/tiny-secp256k1/lib/index.js:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import { compare } from "uint8array-tools";
                                                                                      ^^^^^^

SyntaxError: Cannot use import statement outside a module

I cannot tell if this issue is isolated to the library, or is caused by my configuration. I can import other libraries without complication.

jest.config.ts

export default {
    verbose: true,
    transform: {
        '^.+\\.(ts|tsx)?$': 'ts-jest',
    },
    testPathIgnorePatterns: ['__tests__/helpers'],
};

tsconfig.json

{
    "compilerOptions": {
        "target": "ES2020",
        "module": "commonjs",
        "outDir": "dist",
        "allowJs": false,
        "sourceMap": true,
        "resolveJsonModule": true,
        "esModuleInterop": true,
        "allowSyntheticDefaultImports": true
    },
    "exclude": ["__tests__/"]
}

Ah sorry, no. It was a small project and I was on a time constraint so I ended up just switching over to use javascript instead. I had to redesign a significant amount of code still. I used jsdoc instead of typescript too but that really isn't the best solution. Sorry I couldn't have been more help. — Octal, Jan 29 '22 at 06:44

score 1 · Accepted Answer · edited Feb 10 '22 at 18:07

I was struggling with this for a while too. I found out that it is some weird issue with jest and the "cjs" modules. Don't know exactly why it's like this but after some research I found this post (Jest won't transform the module - SyntaxError: Cannot use import statement outside a module) that gave me a clue of what I needed to do. Below is my jest.config.js file that solves this issue:

module.exports = {
    preset: "ts-jest",
    moduleFileExtensions: [
        "ts",
        "js",
        "cjs",
        "mjs"
    ],
    transform: {
        "^.+\\.(ts|tsx)$": "ts-jest",
        "node_modules/tiny-secp256k1/lib/cjs/.+\\.(js|ts|cjs|mjs)$": "ts-jest",
        "node_modules/uint8array-tools/src/cjs.+\\.(js|ts|cjs|mjs)$": "ts-jest"
    },
    moduleNameMapper: {
        "^uint8array-tools$": "uint8array-tools/src/cjs",
        "^tiny-secp256k1$": "tiny-secp256k1/lib/cjs"
    },
    transformIgnorePatterns: [
        "node_modules/(?!tiny-secp256k1/lib/cjs/.*)",
        "node_modules/(?!uint8array-tools/src/cjs/.*)"
    ],
    testMatch: [
        "**/test/**/*.test.(ts|js)"
    ],
    testEnvironment: "node"
};

Jest + Typescript Unable to Import Library (tiny-secp256k1)

1 Answers1