react18-lifecycle-patterns

SKILL.md

React 18 Lifecycle Patterns

Reference for migrating the three unsafe class component lifecycle methods to React 18.3.1 compliant patterns.

Quick Decision Guide

Before migrating any lifecycle method, identify the semantic category of what the method does. Wrong category = wrong migration. The table below routes you to the correct reference file.

componentWillMount - what does it do?

What it does
Correct migration
Reference

Sets initial state (this.setState(...))
Move to constructor
→ componentWillMount.md

Runs a side effect (fetch, subscription, DOM)
Move to componentDidMount
→ componentWillMount.md

Derives initial state from props
Move to constructor with props
→ componentWillMount.md

componentWillReceiveProps - what does it do?