E0191: event attributes must be camelCase

In HTML, attributes are case-insensitive; onclick is the same as onClick and ONCLICK. In React, attributes are case-sensitive. It is a mistake for an event attribute (starting with on) to be all lower-case:

import React from "react";

function TodoEntry({addTodo, changePendingTodo}) {
  return <form onsubmit={addTodo}>
    <input onchange={changePendingTodo} />
    <button>add todo</button>
  </form>;
}

To fix this error, fix the capitalization by writing the attribute in lowerCamelCase:

import React from "react";

function TodoEntry({addTodo, changePendingTodo}) {
  return <form onSubmit={addTodo}>
    <input onChange={changePendingTodo} />
    <button>add todo</button>
  </form>;
}

This diagnostic enabled in the "react" JSX mode.

Introduced in quick-lint-js version 2.0.0.

Documentation for other errors