@mizchi/svelte-printer

Svelte

npm install @mizchi/svelte-printer prettier;

import { printCode } from '@mizchi/svelte-printer';
import { parse } from 'svelte/compiler';

const code = `<script>let x = 1</script>
<button on:click={() => x += 1}>{x}</button>
`;

const parsed = parse(code);
const printed = printCode(ast);
console.log(printed);

---

Prettier for Svelte 3 components

Format your Svelte components using Prettier.

Features

• Format your HTML, CSS, and JavaScript using prettier
• Format Svelte syntax, e.g. each loops, if statements, await blocks, etc.
• Format the JavaScript expressions embedded in the Svelte syntax
  • e.g. expressions inside of {}, event bindings on:click="", and more

How to use in VS Code and Atom

This plugin comes with Svelte for VS Code and Svelte for Atom so just install the extension for your favorite editor and enjoy.

If you want to customize some formatting behavior, see section "Options" below.

Some of the extensions let you define options through extension-specific configuration. These settings are ignored however if there's any configuration file (.prettierrc for example) present.

How to install manually

npm i --save-dev prettier-plugin-svelte prettier

How to use (CLI)

Install prettier and prettier-plugin-svelte as dev dependencies in your project.

Then format your code using Prettier CLI. You may need to add --plugin-search-dir=.

prettier --write --plugin-search-dir=. ./**/*.html

If you want to customize some formatting behavior, see section "Options" below.

Options

Configurations are optional

Make a .prettierrc file in your project directory (Read more about prettier config files here) and add your preferred configuration options. When using Prettier through the CLI, you can also pass options through CLI flags, but a .prettierrc file is recommended.

Svelte Sort Order

Sort order for svelte:options, scripts, markup, and styles.

Format: join the keywords options, scripts, markup, styles with a - in the order you want.

Default	CLI Override	API Override
options-scripts-markup-styles	--svelte-sort-order <string>	svelteSortOrder: <string>

The options order option only exists since version 2. If you use version 1 of prettier-plugin-svelte, omit that option (so for example only write scripts-markup-styles).

Svelte Strict Mode

More strict HTML syntax: less self-closed tags, quotes in attributes, no attribute shorthand (overrules svelteAllowShorthand).

Example:

<!-- svelteStrictMode: true -->
<div foo="{bar}"></div>

<!-- svelteStrictMode: false -->
<div foo="{bar}" />

Default	CLI Override	API Override
false	--svelte-strict-mode <bool>	svelteStrictMode: <bool>

Svelte Allow Shorthand

Option to enable/disable component attribute shorthand if attribute name and expression are same.

Example:

<!-- allowShorthand: true -->
<input type="text" {value} />

<!-- allowShorthand: false -->
<input type="text" value="{value}" />

Default	CLI Override	API Override
true	--svelte-allow-shorthand <bool>	svelteAllowShorthand: <bool>

Svelte Bracket New Line

Put the > of a multiline element on a new line. Roughly the Svelte equivalent of the jsxBracketSameLine rule. Setting this to false will have no effect for whitespace-sensitive tags (inline elements) when there's no whitespace between the > of the start tag and the inner content, or when there's no whitespace after the > of the end tag.

Example:

<!-- before formatting -->
<span
    ><div>foo</div>
    <span>bar</span></span
>
<div pretend break>content</div>

<!-- after formatting, svelteBracketNewLine true -->
<span
    ><div>foo</div>
    <span>bar</span></span
>
<div pretend break>content</div>

<!-- after formatting, svelteBracketNewLine false -->
<span
    ><div>foo</div>
    <span>bar</span></span
>
<div pretend break>content</div>

Default	CLI Override	API Override
true	--svelte-bracket-new-line <bool>	svelteBracketNewLine: <bool>

Svelte Indent Script And Style

Whether or not to indent the code inside <script> and <style> tags in Svelte files. This saves an indentation level, but might break code folding in your editor.

Default	CLI Override	API Override
true	--svelte-indent-script-and-style <bool>	svelteIndentScriptAndStyle: <bool>

.prettierrc example

{
    "svelteSortOrder": "options-styles-scripts-markup",
    "svelteStrictMode": true,
    "svelteBracketNewLine": false,
    "svelteAllowShorthand": false,
    "svelteIndentScriptAndStyle": false
}