topic Re: 🔥 ArcGIS JS API can't be used in Jest unit tests in ArcGIS JavaScript Maps SDK Questions

🔥 ArcGIS JS API can't be used in Jest unit tests

RussellMGreen — Thu, 16 Nov 2023 18:47:19 GMT

Trying to use the ArcGIS JS API in a unit test in Jest results in an import error:

Environment:

OS: Windows 10

Node: v20.1.0

Setup: nx repo > library > jest unit test

This issue can be found by simply creating a new NX monorepo/project and creating a TypeScript library and trying to use any ArcGIS JS API class within a Jest spec file (unit test).

Example:

`my-test.spec.ts`

// This import will fail! import { Point } from '@arcgis/core/geometry'; describe('my test', ()=>{ it('will fail', ()=>{ new Point({ latitude: 42, longitude: -72 }); }); });

Steps to Reproduce:

git clone https://github.com/rustygreen/arcgis-js-api-issue-example.git
cd arcgis-js-api-issue-example
npm install
npm run test -- arcgis-angular
🔥 test will fail with import error

Re: 🔥 ArcGIS JS API can't be used in Jest unit tests

AndyGup — Thu, 16 Nov 2023 21:05:08 GMT

It's been a while since I used Jest with Angular and no guarantee that it will work, but you may need to do something like this in your Jest config:

"transformIgnorePatterns": [
"node_modules/(?!(@angular|@arcgis|@esri|@stencil/)"
],

And, you might also need: https://www.npmjs.com/package/jest-preset-angular.

Re: 🔥 ArcGIS JS API can't be used in Jest unit tests

RussellMGreen — Thu, 16 Nov 2023 21:17:19 GMT

The current Jest config in the sample repo should already be handling this dynamically (unless I'm missing something):

arcgis-js-api-issue-example/libs/arcgis-angular/jest.config.ts at main · rustygreen/arcgis-js-api-issue-example (github.com)

Also, just to note; you can take Angular out of this mix and the same issue will occur. I just happened to create the library as an Angular library using the NX cli.

Re: 🔥 ArcGIS JS API can't be used in Jest unit tests

AndyGup — Thu, 16 Nov 2023 23:20:04 GMT

Ah okay, I clearly didn't look deep enough. Yep, that ignore pattern isn't working correctly. This isn't a problem with "@arcgis/core". The error "Cannot use import statement outside a module" is a well known JavaScript configuration issue.

I changed this in your app and it worked:

    "transformIgnorePatterns": [
      "node_modules/(?!(@angular|@arcgis|@esri|@stencil|@popperjs)/)"
    ],

Re: 🔥 ArcGIS JS API can't be used in Jest unit tests

RussellMGreen — Fri, 17 Nov 2023 14:40:15 GMT

Yep, that solved it. Thanks, @AndyGup!