Disallows elements with duplicated ID (no-dup-id)

The ID of an element must be unique.

Rule details

Examples of incorrect code for this rule:

<div id="foo"></div>
<div id="foo"></div>

error: Duplicate ID "foo" (no-dup-id) at inline:2:10:
  1 | <div id="foo"></div>
> 2 | <div id="foo"></div>
    |          ^^^


1 error found.

Examples of correct code for this rule:

<div id="foo"></div>
<div id="bar"></div>