66 lines
2.0 KiB
Markdown
66 lines
2.0 KiB
Markdown
# LitElement TypeScript starter
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This project includes a sample component using LitElement with TypeScript.
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## Setup
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Install dependencies:
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```bash
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npm i
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```
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## Build
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This sample uses the TypeScript compiler to produce JavaScript that runs in modern browsers.
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To build the JavaScript version of your component:
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```bash
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npm run build
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```
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To watch files and rebuild when the files are modified, run the following command in a separate shell:
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```bash
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npm run build:watch
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```
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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.
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## Testing
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This sample uses Karma, Chai, Mocha, and the open-wc test helpers for testing. See the [open-wc testing documentation](https://open-wc.org/testing/testing.html) for more information.
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Tests can be run with the `test` script:
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```bash
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npm test
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```
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## Dev Server
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This sample uses open-wc's [es-dev-server](https://github.com/open-wc/open-wc/tree/master/packages/es-dev-server) for previewing the project without additional build steps. ES 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.
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To run the dev server and open the project in a new browser tab:
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```bash
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npm run serve
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```
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## Linting
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Linting of TypeScript files is provided by [ESLint](eslint.org) and [TypeScript ESLint](https://github.com/typescript-eslint/typescript-eslint). In addition, [lit-analyzer](https://www.npmjs.com/package/lit-analyzer) is used to type-check and lint lit-html templates.
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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`.
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To lint the project run:
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```bash
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npm run lint
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```
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## More information
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See [Get started](https://lit-element.polymer-project.org/guide/start) on the LitElement site for more information.
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