Setup

Install dependencies:

pnpm install

Build

This sample uses the TypeScript compiler to produce JavaScript that runs in modern browsers.

To build the JavaScript version of your component:

npm run build

To watch files and rebuild when the files are modified, run the following command in a separate shell:

npm run build:watch

Both the TypeScript compiler and lit-analyzer are configured to be very strict. You may want to change tsconfig.json to make them less strict.

Dev Server

This sample uses modern-web.dev's @web/dev-server for previewing the project without additional build steps. Web Dev Server handles resolving Node-style "bare" import specifiers, which aren't supported in browsers. It also automatically transpiles JavaScript and adds polyfills to support older browsers. See modern-web.dev's Web Dev Server documentation for more information.

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.