Unexpected token 'export' when testing Angular app with Jest

[oxyeez]

When I run a jest test on a service importing ol-contextmenu, I have the error :

Test suite failed to run

    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.

    You'll find more details and examples of these config options in the docs:
    https://jestjs.io/docs/configuration
    For information about custom transformations, see:
    https://jestjs.io/docs/code-transformation

    Details:

    path/to/project/node_modules/ol-contextmenu/dist/ol-contextmenu.d.ts:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){export * from './main'
                                                                                      ^^^^^^

    SyntaxError: Unexpected token 'export'

      4 | import { Graticule, ImageTile, Map, Overlay, Tile, View } from 'ol';
    > 5 | import ContextMenu, { CallbackObject } from 'ol-contextmenu';
        | ^
      6 | import TileState from 'ol/TileState';
      7 | import { ScaleLine, defaults as defaultControls } from 'ol/control';
      8 | import ControlMousePosition from 'ol/control/MousePosition';

      at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1505:14)
      at Object.<anonymous> (src/app/services/my-service/my-service.service.ts:10:1)
      at Object.<anonymous> (src/app/services/my-service/my-service.service.spec.ts:10:1)

It's not related to the test because the test file is still the default one, only checking if the service is created well.

I've had the same issue when importing openlayers dependency, and I've fixed that by running a babel script :

babel node_modules/ol --extensions .js --out-dir node_modules/.compiled/ol --presets @babel/preset-env --source-maps

and adding in the jest.config.ts file :

transformIgnorePatterns: ['node_modules/(?!.*\\.mjs$)'],
moduleNameMapper: {
  'lodash-es': 'lodash',
  '^ol/(.*)$': 'node_modules/.compiled/ol/$1.js',
},
moduleDirectories: ['node_modules/.compiled', 'node_modules'],

So I did the same for the ol-contextmenu dependency, running first the babel script :

babel node_modules/ol-contextmenu/dist --extensions .js --out-dir node_modules/.compiled/ol-contextmenu/dist --presets @babel/preset-env --source-maps

and changing 'moduleNameMapper' of the jest.config.ts file to :

  moduleNameMapper: {
    'lodash-es': 'lodash',
    '^ol/(.*)$': 'node_modules/.compiled/ol/$1.js',
    '^ol-contextmenu/(.*)$': 'node_modules/.compiled/ol-contextmenu/$1.js',
  },

Does anyone had this issue and solved it?