Start Date: 2019-11-08
Target Major Version: 3.x
Reference Issues: N/A
Implementation PR: N/A

Summary

Drop support for using numbers (keyCodes) as v-on modifiers
Remove config.keyCodes

Basic example

N/A

Motivation

In Vue 2.x, v-on already supports using the kebab-case version of any valid KeyboardEvent.key as a modifier. For example, to trigger the handler only when event.key === 'PageDown':

<input @keyup.page-down="onArrowUp">

This makes number keyCodes and config.keyCodes redundant. In addition, KeyboardEvent.keyCode has been deprecated, so it would make sense for Vue to stop supporting it as well.

Drawbacks

N/A

Alternatives

N/A

Adoption strategy

A codemod can detect usage of number keyCode modifier usage and convert it to key equivalents.
In compat build, config.keyCode can be supported, and the runtime can emit warning when a keyCode alias is matched to allow easy migration.