JavaScriptJestNode.js

Testing React component including SVG file by using Jest and tsdx

When we use an SVG file inside a React component, the test will be throwing these error. Solution: use jest-sv […]

広告ここから
広告ここまで

When we use an SVG file inside a React component, the test will be throwing these error.

  ● Test suite failed to run

Jest encountered an unexpected token

This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.

By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".

Here's what you can do:
 • 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/en/configuration.html

Details:

Solution: use jest-svg-transformer to support an SVG file

Using the jest-svg-transformer library, we can test the React component that using an SVG file.

% yarn add -D jest-svg-transformer

If you using tsdx, we can put a new jest.config.js file like this example.

const {createJestConfig} = require('tsdx/dist/createJestConfig');
const {paths} = require('tsdx/dist/constants');

const config = createJestConfig(undefined, paths.appRoot)
config.transform["^.+\\.svg$"] = "jest-svg-transformer"
module.exports = config;

The SVG image does not render, but the test does not failed

The solution is not complete. Because the SVG file does not render on the test.

 PASS  src/components/Copyright/Copyright.spec.tsx
● Console

  console.error
    Warning: Invalid value for prop `src` on <img> tag. Either remove it from the element, or pass a string or number value to keep it in the DOM. For details, see https://reactjs.org/link/attribute-behavior 
        at img
        at ImageDigitalcubeLogo
        at a
        at small
        at p
        at footer

But, we can complete running the test, so I prefer to use the way until finding another solution.

ブックマークや限定記事(予定)など

WP Kyotoサポーター募集中

WordPressやフロントエンドアプリのホスティング、Algolia・AWSなどのサービス利用料を支援する「WP Kyotoサポーター」を募集しています。
月額または年額の有料プランを契約すると、ブックマーク機能などのサポーター限定機能がご利用いただけます。

14日間のトライアルも用意しておりますので、「このサイトよく見るな」という方はぜひご検討ください。

広告ここから
広告ここまで

Related Category posts