react18-lifecycle-patterns
Provides exact before/after migration patterns for the three unsafe class component lifecycle methods - componentWillMount, componentWillReceiveProps, and componentWillUpdate - targeting React 18.3.1. Use this skill whenever a class component needs its lifecycle methods migrated, when deciding between getDerivedStateFromProps vs componentDidUpdate, when adding getSnapshotBeforeUpdate, or when fixing React 18 UNSAFE_ lifecycle warnings. Always use this skill before writing any lifecycle migration code - do not guess the pattern from memory, the decision trees here prevent the most common migrat
Profile →npx skills add github/awesome-copilot --skill react18-lifecycle-patterns --agent copilot
Same command for any agent — swap --agent for claude-code, codex, cursor.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# 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](references/componentWillMount.md#case-a) | | Runs a side effect (fetch, subscription, DOM) | Move to `componentDidMount` | [→ componentWillMount.md](references/componentWillMount.md#case-b) | | Derives initial state from props | Move to `constructor` with props | [→ componentWillMount.md](references/componentWillMount.md#case-c) | ### componentWillReceiveProps - what does it do? | What it does | Correct migration | Reference | |---|---|---| | Async side effect triggered by prop change (fetch, cancel) | `componentDidUpdate` | [→ componentWillReceiveProps.md](references/componentWillReceiveProps.md#case-a) | | Pure state derivation from
- Quick Decision Guide
- componentWillMount - what does it do?
- componentWillReceiveProps - what does it do?
- componentWillUpdate - what does it do?
- The UNSAFE Prefix Rule
- Reference Files
What does the react18-lifecycle-patterns skill do?
Provides exact before/after migration patterns for the three unsafe class component lifecycle methods - componentWillMount, componentWillReceiveProps, and componentWillUpdate - targeting React 18.3.1. Use this skill whenever a class component needs its lifecycle methods migrated, when deciding between getDerivedStateFromProps vs componentDidUpdate, when adding getSnapshotBeforeUpdate, or when fixing React 18 UNSAFE_ lifecycle warnings. Always use this skill before writing any lifecycle migration code - do not guess the pattern from memory, the decision trees here prevent the most common migrat
How do I install it?
Run `npx skills add github/awesome-copilot --skill react18-lifecycle-patterns --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From github/awesome-copilot, a repository with 37,432 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.