tagged template syntax for svelte to simplify testing using svelte4
npm install svelte4-htm> Hyperscript Tagged Markup for svelte to simplify testing







> If your are already using babel take a look at [svelte-jsx].
Write svelte components in [jsx]-like syntax in Standard JavaScript [Tagged Templates] which works in [all modern browsers] and in node.
This is especially useful for testing svelte components.
``sh`
npm install --save-dev svelte-htm
And then import it:
`js
// using es modules
import html from 'svelte-htm';
// common.js
const html = require('svelte-htm');
`
Alternatively use UNPKG or jsDelivr packages:
With script tags and globals:
`html
`
Hotlinking from unpkg: _(no build tool needed!)_
`js`
import html from 'https://unpkg.com/svelte-htm?module';
`js
import {render, fireEvent} from '@testing-library/svelte';
import html from 'svelte-htm';
import Button from '../src/Button.svelte';
test('should render', async () => {
let clicked = 0;
const {getByRole} = render(html<${Button} on:click=${() => (clicked += 1)}>Click Me!/>);
const button = getByRole('button');
await fireEvent.click(button);
expect(clicked).toBe(1);
});
`
We aim to support all svelte features. In some cases this is not possible. For those cases we provided feasible workarounds. See [svelte-hyperscript] for further details.
Some notable differences are:
- Using stores to allow reactivity
`js
import {render} from '@testing-library/svelte';
import userEvent from '@testing-library/user-event';
import {writable, get} from 'svelte/store';
test('write into an input', async () => {
const text = writable();
const {getByRole} = render(html);
const input = getByRole('textbox');
await userEvent.type(input, 'some text');
expect(get(text)).toBe('some text');
});
`
- Action properties lack the possibility to pass parameters to the action
`js
import action from 'some-action-module';
html
;
`Related Projects
- [svelte-jsx] - write svelte components using [jsx]
- [svelte-hyperscript] - the core of this implementation
- [svelte-fragment-component] - a utility component
- htm - making Hyperscript Tagged Markup possible
- @testing-library/svelte - helps to test UI components in a user-centric way
Support
This project is free and open-source, so if you think this project can help you or anyone else, you may star it on GitHub. Feel free to open an issue if you have any idea, question, or you've found a bug.
Contribute
Thanks for being willing to contribute!
Working on your first Pull Request? You can learn how from this _free_ series How to Contribute to an Open Source Project on GitHub
We are following the Conventional Commits convention.
$3
-
npm test: Run test suite
- npm run build: Generate bundles
- npm run lint: Lints codeNPM Statistics

License
svelte-htm` is open source software licensed as MIT.[tagged templates]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals#Tagged_templates
[all modern browsers]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals#Browser_compatibility
[jsx]: https://reactjs.org/docs/introducing-jsx.html
[svelte-jsx]: https://www.npmjs.com/package/svelte-jsx
[svelte-hyperscript]: https://www.npmjs.com/package/svelte-hyperscript
[svelte-fragment-component]: https://www.npmjs.com/package/svelte-fragment-component
This package is originally written by kenoxa (Sascha Tandel). I edited personally to be using Svelte v4 since non updated was published yet.