Welcome to Jenkins.io Web Components

This is an attempt to build web components that can be used across various jenkins.io based projects

Setup

Install dependencies:

npm i

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.

Testing

This sample uses modern-web.dev's @web/test-runner for testing. See the modern-web.dev testing documentation for more information.

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:

npm test

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:

npm test:watch

Alternatively the test:prod and test:prod:watch commands will run your tests in Lit's production mode.

Dev Server

To run the dev server and open the project in a new browser tab:

npm run storybook

Editing

If you use VS Code, we highly recommend the lit-plugin extension, which enables some extremely useful features for lit-html templates:

• Syntax highlighting
• Type-checking
• Code completion
• Hover-over docs
• Jump to definition
• Linting
• Quick Fixes

The project is setup to recommend lit-plugin to VS Code users if they don't already have it installed.

Linting

Linting of TypeScript files is provided by ESLint and TypeScript ESLint. In addition, lit-analyzer is used to type-check and lint lit-html templates with the same engine and rules as lit-plugin.

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 .eslintrc.json and tsconfig.json.

To lint the project run:

npm run lint

Formatting

Prettier is used for code formatting. It has been pre-configured according to the Lit's style. You can change this in .prettierrc.json.

Prettier has not been configured to run when committing files, but this can be added with Husky and and pretty-quick. See the prettier.io site for instructions.