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I have spent a long time looking at other questions about this and looking at other projects on Github but none of the answers seem to work for me.

I am loading a third party library in my project, and when running Jest tests I get the error

export default portalCommunication;
^^^^^^
SyntaxError: Unexpected token export
> 1 | import portalCommunication from 'mathletics-portal-communication-service';
I have tried updating my Jest config in many ways to get it to transpile this library but I always get the same error.
This is my current jest.config.js file:
module.exports = {
    moduleNameMapper: {
        '\\.(css|scss)$': 'identity-obj-proxy',
        '\\.svg$': '<rootDir>/test/mocks/svg-mock.js'
    setupFiles: ['./test/test-setup.js'],
    transformIgnorePatterns: [
        '<rootDir>/node_modules/(?!mathletics-portal-communication-service)'
I have also tried adding the transform property to run babel-jest against this mathletics-portal-communication-service directory.
Please help!
                My project has babel set up and working fine, is there something special I would need to do for Jest? I thought it used babel-jest automatically?
– Heather Roberts
                May 3, 2018 at 23:33
The transformIgnorePatterns didn't work for me until I changed my .babelrc to babel.config.js, like this:
module.exports = {
    "presets": [
        "@babel/preset-env"
as seen on this comment: https://github.com/facebook/jest/issues/6229#issuecomment-403539460
                Do you know if a .babelrc or babel.config.js file is absolutely necessary? I'm trying to get mine working with just a transformIgnorePatterns declaration in my package.json
– Yorkshireman
                Oct 23, 2019 at 16:46
                Looking at the linked github issue, it seems like it won't work in the package.json either, but I haven't tried it.
– NJCodeMonkey
                Oct 24, 2019 at 22:02
                This response is underrated!! I had been bumping my head for several hours until I saw this! Heck this should be in the docs!
– Samuel Imolorhe
                Jan 9, 2020 at 14:26
Another team at my org added some common module. This was not transpiled and so the issue.
I followed this: https://babeljs.io/docs/en/configuration#whats-your-use-case
Converted my .babelrc to babel.config.json
in jest config added this:
transformIgnorePatterns: ['/node_modules/(?!(@companyName)/).*/'],
This solved my problem.
As a workaround for now I have changed my config to use the moduleNameMapper option to load a mock class for that library instead. I would have preferred to use transformIgnorePatterns instead so would still appreciate any ideas.
New config:
module.exports = {
    moduleNameMapper: {
        '\\.(css|scss)$': 'identity-obj-proxy',
        '\\.svg$': '<rootDir>/test/mocks/svg-mock.js',
        'mathletics-portal-communication-service': '<rootDir>/test/mocks/mathletics-portal-communication-service-mock.js'
    setupFiles: ['./test/test-setup.js']
    // ...
    transformIgnorePatterns: [
        '<rootDir>/node_modules/(?!mathletics-portal-communication-service/)'
        
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