Im trying to resolve the issue I encounter when Im trying to update jest in my package.json

jest 26.6.3 → 27.0.1

Im receiving error

TypeError: require(...).createTransformer is not a function
at Object.<anonymous> (/local/repo/elukchm/monorepo/packages/edf/jestPreprocess.js:34:40)
at Module._pile (internal/modules/cjs/loader.js:1137:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1157:10)
at Module.load (internal/modules/cjs/loader.js:985:32)
at Function.Module._load (internal/modules/cjs/loader.js:878:14)

The code mentioned in files:

jestPreprocess.js

const babelOptions = {
...
};

module.exports = require("babel-jest").createTransformer(babelOptions);

Inside "babel-jest"

const createTransformer = userOptions => {
var _inputOptions$plugins, _inputOptions$presets;

const inputOptions =
userOptions !== null && userOptions !== void 0 ? userOptions : {};
const options = {
...
};

Could you please take a look and tell what should I change? Thank you in advance.

Im trying to resolve the issue I encounter when Im trying to update jest in my package.json

jest 26.6.3 → 27.0.1

Im receiving error

TypeError: require(...).createTransformer is not a function
at Object.<anonymous> (/local/repo/elukchm/monorepo/packages/edf/jestPreprocess.js:34:40)
at Module._pile (internal/modules/cjs/loader.js:1137:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1157:10)
at Module.load (internal/modules/cjs/loader.js:985:32)
at Function.Module._load (internal/modules/cjs/loader.js:878:14)

The code mentioned in files:

jestPreprocess.js

const babelOptions = {
...
};

module.exports = require("babel-jest").createTransformer(babelOptions);

Inside "babel-jest"

const createTransformer = userOptions => {
var _inputOptions$plugins, _inputOptions$presets;

const inputOptions =
userOptions !== null && userOptions !== void 0 ? userOptions : {};
const options = {
...
};

Could you please take a look and tell what should I change? Thank you in advance.

• javascript
• node.js
• require

1 Answer 1

babel-jest@27 switched to ESM, so require is now getting the whole exported scope rather than just the default. Super simple to fix:

module.exports = require("babel-jest").createTransformer(babelOptions);
-->
module.exports = require("babel-jest").default.createTransformer(babelOptions);