This template is generated from the
lit-starter-js package in the main Lit
repo. Issues and PRs for this template should be
filed in that repo.
This is a pre-release of Lit 3.0, the next major version of Lit.
Lit 3.0 has very few breaking changes from Lit 2.0:
Lit 3.0 should require no changes to upgrade from Lit 2.0 for the vast majority of users. Once the full release is published, most apps and libraries will be able to extend their npm version ranges to include both 2.x and 3.x, like
"^2.7.0 || ^3.0.0".
Lit 2.x and 3.0 are interoperable: templates, base classes, directives, decorators, etc., from one version of Lit will work with those from another.
Please file any issues you find on our issue tracker.
Tests can be run with the
test script, which will run your tests against Lit's development mode (with more verbose errors) as well as against Lit's production mode:
For local testing during development, the
test:dev:watch command will run your tests in Lit's development mode (with verbose errors) on every change to your source files:
test:prod:watch commands will run your tests in Lit's production mode.
To run the dev server and open the project in a new browser tab:
npm run serve
There is a development HTML file located at
/dev/index.html that you can view at http://localhost:8000/dev/index.html. Note that this command will serve your code using Lit's development mode (with more verbose errors). To serve your code against Lit's production mode, use
npm run serve:prod.
If you use VS Code, we highly recommend the lit-plugin extension, which enables some extremely useful features for lit-html templates:
The project is setup to recommend lit-plugin to VS Code users if they don't already have it installed.
The rules are mostly the recommended rules from each project, but some have been turned off to make LitElement usage easier. The recommended rules are pretty strict, so you may want to relax them by editing
To lint the project run:
npm run lint
Prettier is used for code formatting. It has been pre-configured according to the Lit's style. You can change this in
Prettier has not been configured to run when committing files, but this can be added with Husky and
pretty-quick. See the prettier.io site for instructions.
This project includes a simple website generated with the eleventy static site generator and the templates and pages in
/docs-src. The site is generated to
/docs and intended to be checked in so that GitHub pages can serve the site from
/docs on the master branch.
To enable the site go to the GitHub settings and change the GitHub Pages "Source" setting to "master branch /docs folder".
To build the site, run:
npm run docs
To serve the site locally, run:
npm run docs:serve
To watch the site files, and re-build automatically, run:
npm run docs:watch
The site will usually be served at http://localhost:8000.
Note: The project uses Rollup to bundle and minify the source code for the docs site and not to publish to NPM. For bundling and minification, check the Bundling and minification section.
As stated in the static site generation section, the bundling and minification setup in the Rollup configuration in this project is there specifically for the docs generation.
Please check the Publishing best practices for information on publishing reusable Web Components, and Build for production for building application projects that include LitElement components, on the Lit site.
See Get started on the Lit site for more information.