Unable to test Lightweight-Charts in React app

Question

In my Create React App when importing the lightweight-chars like so everything's working:

import { createChart } from 'lightweight-charts';

However, when running tests with:

yarn test --all

this error is shown:

● Test suite failed to run

.../node_modules/lightweight-charts/dist/lightweight-charts.esm.development.js:7
import { bindToDevicePixelRatio } from 'fancy-canvas/coordinate-space';
^^^^^^

SyntaxError: Cannot use import statement outside a module

  at ScriptTransformer._transformAndBuildScript (node_modules/@jest/transform/build/ScriptTransformer.js:537:17)
  ...

Please suggest if looks familiar.

timocov · Answer 1 · 2020-12-11T22:29:14.320

2

Currently it's impossible to use/import lightweight-charts in nodejs context. You can subscribe on https://github.com/tradingview/lightweight-charts/issues/488 to be notified when it'll be solved.

edited Dec 11 '20 at 22:29

answered Dec 10 '20 at 07:18

timocov

1,088
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Till Kolter · Answer 2 · 2021-02-23T23:20:44.540

2

It might not be the perfect solution to fix the root cause, but I was able to fix the errors via jest option in package.json.

...
"transformIgnorePatterns": [
      "node_modules/(?!(lightweight-charts|fancy-canvas)/)"
    ]

edited Feb 23 '21 at 23:20

answered Feb 23 '21 at 19:53

Till Kolter

602
1
9
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score 0 · Answer 3 · answered Jun 19 '22 at 17:18

This is the only thing that worked for me:

npm test -- --transformIgnorePatterns "node_modules/(?!(lightweight-charts|fancy-canvas)/)"

This worked for me because I have an unejected create react app project and therefore transformIgnorePatterns is not available via jest.config.js or the package.json.

Unable to test Lightweight-Charts in React app

3 Answers3