#no-late-event-control

#Configuration

import { defineConfig, unicornPlugin } from '@rslint/core';

export default defineConfig([
  unicornPlugin.configs.recommended,
  {
    rules: {
      'unicorn/no-late-event-control': 'error',
    },
  },
]);

#Rule details

Disallow calling preventDefault(), stopPropagation(), or stopImmediatePropagation() on an event after synchronous dispatch has finished. Call these methods before the handler suspends or defers work.

The rule recognizes common event parameter names such as e, event, evt, and mouseDownEvent, as well as DOM and React event types. A known non-event type takes precedence over the name.

Examples of incorrect code for this rule

element.addEventListener("click", async (event) => {
  await save();
  event.preventDefault();
});

element.addEventListener("click", (event) => {
  setTimeout(() => {
    event.stopPropagation();
  });
});

Examples of correct code for this rule

element.addEventListener("click", async (event) => {
  event.preventDefault();
  await save();
});

element.addEventListener("click", (event) => {
  event.stopPropagation();
  setTimeout(() => {
    update();
  });
});

#Limitations

• The rule reports calls inside nested functions, including callbacks that run synchronously. It also reports calls in generator handler bodies, which run when the iterator advances.
• The rule treats an earlier await or yield as a suspension even when the suspension and the call are in mutually exclusive branches. It also checks repeated parts of loops that can suspend.
• The rule checks calls on the original parameter. Calls on aliases or in a separate function that receives the event can go undetected.

#Differences from upstream

Rslint recognizes event types passed through a local generic alias even without TypeScript project information. For example, if type Identity<T> = T, a parameter declared as input: Identity<MouseEvent> is still checked for late calls. Upstream needs project information to report that case.

Rslint reports calls in instance field initializers because those run when an instance is created. Static fields and computed names are checked in the surrounding handler because they run during class evaluation.

Generator parameter defaults run synchronously when the handler is called, so Rslint allows direct event-control calls there. It reports calls in the generator body and callbacks that capture the event.

#Original documentation

• Upstream documentation
• Upstream source