Coding & Refactoringlow risk
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 migration mistakes.
github/awesome-copilot·skills/react18-lifecycle-patterns/SKILL.md
100/ 100品質分
匯入這個 Skill
選擇你的 coding agent，複製專案級或個人級安裝指令。
匯入目前專案.agents/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a codex -y匯入個人環境~/.agents/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a codex -g -y匯入目前專案.claude/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a claude-code -y匯入個人環境~/.claude/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a claude-code -g -y匯入目前專案.agents/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a github-copilot -y匯入個人環境~/.copilot/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a github-copilot -g -y匯入目前專案.agents/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a cursor -y匯入個人環境~/.cursor/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a cursor -g -y匯入目前專案.agents/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a gemini-cli -y匯入個人環境~/.gemini/skills/react18-lifecycle-patterns
npx skills add https://github.com/github/awesome-copilot/tree/0aaced533251f5b86c69dfbc5e55db74c4b4d1af/skills/react18-lifecycle-patterns -a gemini-cli -g -yNative Gemini CLI
gemini skills install https://github.com/github/awesome-copilot.git --scope workspace --path skills/react18-lifecycle-patterns⚠ 安裝指令使用開源 skills CLI。執行前請檢查來源、腳本與權限。
Skill 指令
在 GitHub 查看原始檔案 ↗# 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 new props (no side effects) | `getDerivedStateFromProps` | [→ componentWillReceiveProps.md](references/componentWillReceiveProps.md#case-b) | ### componentWillUpdate - what does it do? | What it does | Correct migration | Reference | |---|---|---| | Reads the DOM before update (scroll, size, position) | `getSnapshotBeforeUpdate` | [→ componentWillUpdate.md](references/componentWillUpdate.md#case-a) | | Cancels requests / runs effects before update | `componentDidUpdate` with prev comparison | [→ componentWillUpdate.md](references/componentWillUpdate.md#case-b) | --- ## The UNSAFE_ Prefix Rule **Never use `UNSAFE_componentWillMount`, `UNSAFE_componentWillReceiveProps`, or `UNSAFE_componentWillUpdate` as a permanent fix.** Prefixing suppresses the React 18.3.1 warning but does NOT: - Fix concurrent mode safety issues - Prepare the codebase for React 19 (where these are removed, with or without the prefix) - Fix the underlying semantic problem the migration is meant to address The UNSAFE_ prefix is only appropriate as a temporary hold while scheduling the real migration sprint. Mark any UNSAFE_ prefix additions with: ```jsx // TODO: React 19 will remove this. Migrate before React 19 upgrade. // UNSAFE_ prefix added temporarily - replace with componentDidMount / getDerivedStateFromProps / etc. ``` --- ## Reference Files Read the full reference file for the lifecycle method you are migrating: - **`references/componentWillMount.md`** - 3 cases with full before/after code - **`references/componentWillReceiveProps.md`** - getDerivedStateFromProps trap warnings, full examples - **`references/componentWillUpdate.md`** - getSnapshotBeforeUpdate + componentDidUpdate pairing Read the relevant file before writing any migration code.