Jest tests fail after using 'csv-parse/sync' lirbary

Question

I am using NestJs with Nx.dev for monorepo. After I installed csv-parse/sync and used my Jest tests don't work anymore.

Jest encountered an unexpected token

Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.

Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.

By default "node_modules" folder is ignored by transformers.

Here's what you can do:
 • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
 • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
 • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
 • If you need a custom transformation specify a "transform" option in your config.
 • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.

Details:

    /home/username/project/node_modules/csv-parse/lib/sync.js:2
    import { Parser } from './index.js';

I tried to follow the above links but had no luck. Anyone faces the same problem?

have you tried the following? https://github.com/adaltas/node-csv/issues/309 "jest": { "moduleNameMapper":{ "^csv-parse/sync": "/node_modules/csv-parse/dist/cjs/sync.cjs" } }, — Tonino, Jan 31 '22 at 11:36

score 3 · Answer 1 · answered Jun 09 '22 at 10:55

3

add lines to package.json

    "moduleNameMapper": {
      "^csv-parse/sync": "<rootDir>/node_modules/csv-parse/dist/cjs/sync.cjs"
    }

answered Jun 09 '22 at 10:55

user19306150

31
2

1

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community Jun 11 '22 at 06:38

score -1 · Answer 2 · answered Jan 23 '23 at 19:56

What worked for me was adding the line from @user19306150 to my jest.config.js:

  "moduleNameMapper": {
      "^csv-parse/sync": "<rootDir>/node_modules/csv-parse/dist/cjs/sync.cjs"
    }

Here also link to the jest documentation regarding the moduleNameMapper: https://jestjs.io/docs/configuration#modulenamemapper-objectstring-string--arraystring

Jest tests fail after using 'csv-parse/sync' lirbary

2 Answers2