jsx-tag-spacing.md

Validate whitespace in and around the JSX opening and closing brackets (react/jsx-tag-spacing)

Enforce or forbid spaces after the opening bracket, before the closing bracket of self-closing elements, and between the angle bracket and slash of JSX closing or self-closing elements.

Fixable: This rule is automatically fixable using the --fix flag on the command line.

Rule Details

This rule checks the whitespace inside and surrounding the JSX syntactic elements.

This rule takes one argument, an object with 3 possible keys: closingSlash, beforeSelfClosing and afterOpening. Each key can receive the value "allow" to disable that specific check.

The default values are:

{
  "closingSlash": "never",
  "beforeSelfClosing": "always",
  "afterOpening": "never"
}

The options for each sub-option are documented in the following subsections.

closingSlash

This check can be set to "always", "never" or "allow" (to disable it).

If it is "never", the check warns whenever a space is separating the two characters in the JSX tokens </ and />. If it is "always" then it warns whenever a space is missing separating the mentioned two characters. The default value of this check is "never".

The following patterns are considered warnings when configured "never":

<App/ >
<input/
>
<Provider>< /Provider>

The following patterns are not considered warnings when configured "never":

<App/>
<input/>
<Provider></Provider>

The following patterns are considered warnings when configured "always":

<Hello/>
<Goodbye></Goodbye>

The following patterns are not considered warnings when configured "always":

<Hello/ >
<Goodbye>< /Goodbye>

beforeSelfClosing

This check can be set to "always", "never" or "allow" (to disable it).

If it is "always", the check warns whenever a space is missing before the closing bracket. If "never" then it warns if a space is present before the closing bracket. The default value of this check is "always".

The following patterns are considered warnings when configured "always":

<Hello/>
<Hello firstname="John"/>

The following patterns are not considered warnings when configured "always":

<Hello />
<Hello firstName="John" />
<Hello
  firstName="John"
  lastName="Smith"
/>

The following patterns are considered warnings when configured "never":

<Hello />
<Hello firstName="John" />

The following patterns are not considered warnings when configured "never":

<Hello/>
<Hello firstname="John"/>
<Hello
  firstName="John"
  lastName="Smith"
/>

afterOpening

This check can be set to "always", "never", "allow-multiline" or "allow" (to disable it).

If it is "always", the check warns whenever a space is missing after the opening bracket of either a JSX opening element or closing element. If "never" then it warns if a space is present after the opening bracket of either a JSX opening element or closing element. If "allow-multiline" then it behaves like "never", but allows if the separator includes a newline character. The default value of this check is "never".

The following patterns are considered warnings when configured "always":

<Hello></Hello>
<Hello firstname="John"/>
<Hello
  firstName="John"
  lastName="Smith"
/>

The following patterns are not considered warnings when configured "always":

< Hello></ Hello>
< Hello firstName="John"/>
<
  Hello
  firstName="John"
  lastName="Smith"
/>

The following patterns are considered warnings when configured "never":

< Hello></ Hello>
< Hello firstName="John"/>
<
  Hello
  firstName="John"
  lastName="Smith"
/>

The following patterns are not considered warnings when configured "never":

<Hello></Hello>
<Hello firstname="John"/>
<Hello
  firstName="John"
  lastName="Smith"
/>

The following patterns are considered warnings when configured "allow-multiline":

< Hello></ Hello>
< Hello firstName="John"/>
< Hello
  firstName="John"
  lastName="Smith"
/>

The following patterns are not considered warnings when configured "allow-multiline":

<Hello></Hello>
<Hello firstName="John"/>
<
  Hello
  firstName="John"
  lastName="Smith"
/>

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing in or around JSX brackets.