7.5 KiB
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 bindingson:click=""
, and more
- e.g. expressions inside of
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=.
As a one-time run:
npx prettier --write --plugin-search-dir=. ./**/*.html
As part of your scripts in package.json
:
"format": "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 and add your preferred options to configure Prettier. 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; or none
if you don't want Prettier to reorder anything.
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 ofprettier-plugin-svelte
, omit that option (so for example only writescripts-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
Deprecated since 2.5.0. Use Prettier 2.4.0 and bracketSameLine instead.
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. You can read more about HTML whitespace sensitivity here. You can adjust whitespace sensitivity through this setting.
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
}
Usage with Tailwind Prettier Plugin
There is a Tailwind Prettier Plugin to format classes in a certain way. This plugin must be loaded last, so if you want to use the Tailwind plugin, disable Prettier auto-loading and place prettier-plugin-tailwindcss
in the end of the plugins array. If you are using VS Code, make sure to have the Prettier extension installed and switch the default formatter for Svelte files to it.
// .prettierrc
{
// ..
"plugins": [
"prettier-plugin-svelte",
"prettier-plugin-tailwindcss" // MUST come last
],
"pluginSearchDirs": false
}
FAQ
Why is the closing or opening tag (>
or <
) hugging the inner tag or text?
If you are wondering why this code
<span><span>assume very long text</span></span>
becomes this
<span
><span>assume very long text</span
></span
>
it's because of whitespsace sensitivity. For inline elements (span
, a
, etc) it makes a difference when rendered if there's a space (or newline) between them. Since we don't know if your slot inside your Svelte component is surrounded by inline elements, Svelte components are treated as such, too. You can adjust this whitespace sensitivity through this setting. You can read more about HTML whitespace sensitivity here.