Jest test configuration that works with babylon

Demos and projects
1

Hi everyone,

There were a few questions about jest and babylon, and how to use jest, testing your project that uses babylon.

I have added a jest configuration to my babylon template:

babylonjs-webpack-es6/jest.config.js at master · RaananW/babylonjs-webpack-es6 (github.com)

It currently only runs this (very unneeded!) test:

babylonjs-webpack-es6/createScene.unit.test.ts at master · RaananW/babylonjs-webpack-es6 · GitHub

But it should support any (esm) project configuration.

If you have issues, update me, show me examples, show me the errors. I’d be happy to debug it

6 Likes
2

Hi @RaananW

I’m going to necro this thread and take you up on that offer. I’m starting a “Floor is Lava” tutorial and I’m finding if I include any BabylonJS imports, I have failures.

Source: GitHub - kjduling/lava: The Floor is Lava

Errors:

Run npm run build
  npm run build
  shell: /usr/bin/bash -e {0}

> lava@1.0.0 build
> npm test && webpack


> lava@1.0.0 test
> jest

ts-jest[config] (WARN) message TS151001: If you have issues related to imports, you should consider setting `esModuleInterop` to `true` in your TypeScript configuration file (usually `tsconfig.json`). See https://blogs.msdn.microsoft.com/typescript/2018/01/31/announcing-typescript-2-7/#easier-ecmascript-module-interoperability for more information.
ts-jest[config] (WARN) message TS151001: If you have issues related to imports, you should consider setting `esModuleInterop` to `true` in your TypeScript configuration file (usually `tsconfig.json`). See https://blogs.msdn.microsoft.com/typescript/2018/01/31/announcing-typescript-2-7/#easier-ecmascript-module-interoperability for more information.
PASS tests/MathUtil.unit.test.ts (5.902 s)
  ● Console

    console.log
      RandomRange(1, 10)

      at Function.RandomRange (src/MathUtil.ts:10:17)

    console.log
      Shuffle(1,2,3,4,5,6,7,8,9,10)

      at Function.Shuffle (src/MathUtil.ts:20:17)

FAIL tests/Main.unit.test.ts
  ● 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:

    /home/runner/work/lava/lava/node_modules/@babylonjs/core/Debug/debugLayer.js:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import { Tools } from "../Misc/tools.js";
                                                                                      ^^^^^^

    SyntaxError: Cannot use import statement outside a module

    > 1 | import "@babylonjs/core/Debug/debugLayer";
        | ^
      2 | import "@babylonjs/inspector";
      3 | import { ArcRotateCamera, Engine, HemisphericLight, Mesh, Scene, Vector3 } from '@babylonjs/core';
      4 |

      at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1505:14)
      at Object.<anonymous> (src/Main.ts:1:1)
      at Object.<anonymous> (tests/Main.unit.test.ts:1:1)

Test Suites: 1 failed, 1 passed, 2 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        6.376 s
Ran all test suites.
Error: Process completed with exit code 1.

I’ve tried removing the debug imports, but it pushes the error further downstream.

In @babylonjs/inspector it’s failing on

    /Users/kevin/Dev/BabylonJS/lava/node_modules/@babylonjs/core/index.js:2
    export * from "./abstractScene.js";
    ^^^^^^

If I take them both out and just import the classes I need, I get the same error as above.

1 Like
3

Oh, I remember fighting with this one!!

This is node’s fault. Ok, that’s a little bit unfair. This is the javscript’s crazy ecosystem’s fault! There, i said it :slight_smile:

You need to turn on --experimental-vm-modules in node, and then it will work. The best way to do it cross-env i could find was this:

Add cross-env to your dev dependencies (latest is 7.0.3)

then change your test command to this:

cross-env NODE_OPTIONS=--experimental-vm-modules npx jest

Alternatively, you should get away with avoiding installing cross-env as dependency andd running

npx cross-env NODE_OPTIONS=--experimental-vm-modules npx jest,

but that’s not a pretty solution, to say the least.

I hope this helps!

2 Likes
4

That solved it, thanks!

1 Like