Error Boundaries React
Skill Profile
(Select at least one profile to enable specific modules)
Overview
Error boundaries are React components that catch JavaScript errors anywhere in their component tree, log those errors, and display a fallback UI instead of a component tree that crashed. Introduced in React 16, error boundaries are essential for building resilient React applications that can recover from errors gracefully.
Why This Matters
- Reduces Downtime: Error boundaries prevent application crashes by catching and handling errors at component level
- Improves User Retention: Users are less likely to abandon applications with good error handling
- Reduces Support Costs: Good error reporting enables faster diagnosis and resolution of issues
- Builds Trust: Applications that handle errors gracefully build trust with users
- Enhances User Experience: Good fallback UI helps users understand situation and provides recovery options
- Improves Development Velocity: Cleaner, well-structured code is faster to develop and maintain
Core Concepts & Rules
1. Core Principles
- Follow established patterns and conventions
- Maintain consistency across codebase
- Document decisions and trade-offs
2. Implementation Guidelines
- Start with the simplest viable solution
- Iterate based on feedback and requirements
- Test thoroughly before deployment
Inputs / Outputs / Contracts
- Inputs:
- React components
- Error tracking configuration
- Fallback UI components
- User session data
- Entry Conditions:
- React 16+ is available
- Error tracking service is configured
- Fallback UI components are designed
- Outputs:
- Error boundary components
- Error logging integration
- Fallback UI implementations
- Error recovery mechanisms
- Artifacts Required (Deliverables):
- Error boundary components
- Error logging configuration
- Fallback UI components
- Error tracking dashboards
- Acceptance Evidence:
- Errors are caught and logged
- Fallback UI is displayed appropriately
- Users can recover from errors
- Error tracking is configured
- Success Criteria:
- All errors are caught and handled
- User experience is maintained during errors
- Error tracking is working
- Application remains stable
Skill Composition
Quick Start / Implementation Example
- Review requirements and constraints
- Set up development environment
- Implement core functionality following patterns
- Write tests for critical paths
- Run tests and fix issues
- Document any deviations or decisions
# Example implementation following best practices
def example_function():
# Your implementation here
pass
Assumptions / Constraints / Non-goals
- Assumptions:
- Development environment is properly configured
- Required dependencies are available
- Team has basic understanding of domain
- Constraints:
- Must follow existing codebase conventions
- Time and resource limitations
- Compatibility requirements
- Non-goals:
- This skill does not cover edge cases outside scope
- Not a replacement for formal training
Compatibility & Prerequisites
- Supported Versions:
- Python 3.8+
- Node.js 16+
- Modern browsers (Chrome, Firefox, Safari, Edge)
- Required AI Tools:
- Code editor (VS Code recommended)
- Testing framework appropriate for language
- Version control (Git)
- Dependencies:
- Language-specific package manager
- Build tools
- Testing libraries
- Environment Setup:
.env.example keys: API_KEY, DATABASE_URL (no values)
Test Scenario Matrix (QA Strategy)
| Type |
Focus Area |
Required Scenarios / Mocks |
| Unit |
Core Logic |
Must cover primary logic and at least 3 edge/error cases. Target minimum 80% coverage |
| Integration |
DB / API |
All external API calls or database connections must be mocked during unit tests |
| E2E |
User Journey |
Critical user flows to test |
| Performance |
Latency / Load |
Benchmark requirements |
| Security |
Vuln / Auth |
SAST/DAST or dependency audit |
| Frontend |
UX / A11y |
Accessibility checklist (WCAG), Performance Budget (Lighthouse score) |
Technical Guardrails & Security Threat Model
1. Security & Privacy (Threat Model)
- Top Threats: Injection attacks, authentication bypass, data exposure
2. Performance & Resources
3. Architecture & Scalability
4. Observability & Reliability
Agent Directives & Error Recovery
(ข้อกำหนดสำหรับ AI Agent ในการคิดและแก้ปัญหาเมื่อเกิดข้อผิดพลาด)
- Thinking Process: Analyze root cause before fixing. Do not brute-force.
- Fallback Strategy: Stop after 3 failed test attempts. Output root cause and ask for human intervention/clarification.
- Self-Review: Check against Guardrails & Anti-patterns before finalizing.
- Output Constraints: Output ONLY the modified code block. Do not explain unless asked.
Definition of Done (DoD) Checklist
Anti-patterns / Pitfalls
- ⛔ Don't: Log PII, catch-all exception, N+1 queries
- ⚠️ Watch out for: Common symptoms and quick fixes
- 💡 Instead: Use proper error handling, pagination, and logging
Reference Links & Examples
- Internal documentation and examples
- Official documentation and best practices
- Community resources and discussions
Versioning & Changelog
- Version: 1.0.0
- Changelog:
- 2026-02-22: Initial version with complete template structure
Converted and distributed by TomeVault — claim your Tome and manage your conversions.
1---2name: error-boundaries-react3description: Error boundaries are React components that catch JavaScript errors anywhere Use when this capability is needed.4---56# Error Boundaries React78## Skill Profile9*(Select at least one profile to enable specific modules)*10- [ ] **DevOps**11- [x] **Backend**12- [ ] **Frontend**13- [ ] **AI-RAG**14- [ ] **Security Critical**1516## Overview17Error boundaries are React components that catch JavaScript errors anywhere in their component tree, log those errors, and display a fallback UI instead of a component tree that crashed. Introduced in React 16, error boundaries are essential for building resilient React applications that can recover from errors gracefully.1819## Why This Matters20- **Reduces Downtime**: Error boundaries prevent application crashes by catching and handling errors at component level21- **Improves User Retention**: Users are less likely to abandon applications with good error handling22- **Reduces Support Costs**: Good error reporting enables faster diagnosis and resolution of issues23- **Builds Trust**: Applications that handle errors gracefully build trust with users24- **Enhances User Experience**: Good fallback UI helps users understand situation and provides recovery options25- **Improves Development Velocity**: Cleaner, well-structured code is faster to develop and maintain2627---2829## Core Concepts & Rules3031### 1. Core Principles32- Follow established patterns and conventions33- Maintain consistency across codebase34- Document decisions and trade-offs3536### 2. Implementation Guidelines37- Start with the simplest viable solution38- Iterate based on feedback and requirements39- Test thoroughly before deployment404142## Inputs / Outputs / Contracts43* **Inputs**:44 - React components45 - Error tracking configuration46 - Fallback UI components47 - User session data48* **Entry Conditions**:49 - React 16+ is available50 - Error tracking service is configured51 - Fallback UI components are designed52* **Outputs**:53 - Error boundary components54 - Error logging integration55 - Fallback UI implementations56 - Error recovery mechanisms57* **Artifacts Required (Deliverables)**:58 - Error boundary components59 - Error logging configuration60 - Fallback UI components61 - Error tracking dashboards62* **Acceptance Evidence**:63 - Errors are caught and logged64 - Fallback UI is displayed appropriately65 - Users can recover from errors66 - Error tracking is configured67* **Success Criteria**:68 - All errors are caught and handled69 - User experience is maintained during errors70 - Error tracking is working71 - Application remains stable7273## Skill Composition74* **Depends on**: [react-best-practices](../react-best-practices/SKILL.md), [state-management](../state-management/SKILL.md)75* **Compatible with**: [form-handling](../form-handling/SKILL.md), [nextjs-patterns](../nextjs-patterns/SKILL.md)76* **Conflicts with**: None77* **Related Skills**: [animation](../animation/SKILL.md), [infinite-scroll](../infinite-scroll/SKILL.md)7879---8081## Quick Start / Implementation Example82831. Review requirements and constraints842. Set up development environment853. Implement core functionality following patterns864. Write tests for critical paths875. Run tests and fix issues886. Document any deviations or decisions8990```python91# Example implementation following best practices92def example_function():93 # Your implementation here94 pass95```969798## Assumptions / Constraints / Non-goals99100* **Assumptions**:101 - Development environment is properly configured102 - Required dependencies are available103 - Team has basic understanding of domain104* **Constraints**:105 - Must follow existing codebase conventions106 - Time and resource limitations107 - Compatibility requirements108* **Non-goals**:109 - This skill does not cover edge cases outside scope110 - Not a replacement for formal training111112113## Compatibility & Prerequisites114115* **Supported Versions**:116 - Python 3.8+117 - Node.js 16+118 - Modern browsers (Chrome, Firefox, Safari, Edge)119* **Required AI Tools**:120 - Code editor (VS Code recommended)121 - Testing framework appropriate for language122 - Version control (Git)123* **Dependencies**:124 - Language-specific package manager125 - Build tools126 - Testing libraries127* **Environment Setup**:128 - `.env.example` keys: `API_KEY`, `DATABASE_URL` (no values)129130131## Test Scenario Matrix (QA Strategy)132133| Type | Focus Area | Required Scenarios / Mocks |134| :--- | :--- | :--- |135| **Unit** | Core Logic | Must cover primary logic and at least 3 edge/error cases. Target minimum 80% coverage |136| **Integration** | DB / API | All external API calls or database connections must be mocked during unit tests |137| **E2E** | User Journey | Critical user flows to test |138| **Performance** | Latency / Load | Benchmark requirements |139| **Security** | Vuln / Auth | SAST/DAST or dependency audit |140| **Frontend** | UX / A11y | Accessibility checklist (WCAG), Performance Budget (Lighthouse score) |141142143## Technical Guardrails & Security Threat Model144145### 1. Security & Privacy (Threat Model)146* **Top Threats**: Injection attacks, authentication bypass, data exposure147- [ ] **Data Handling**: Sanitize all user inputs to prevent Injection attacks. Never log raw PII148- [ ] **Secrets Management**: No hardcoded API keys. Use Env Vars/Secrets Manager149- [ ] **Authorization**: Validate user permissions before state changes150151### 2. Performance & Resources152- [ ] **Execution Efficiency**: Consider time complexity for algorithms153- [ ] **Memory Management**: Use streams/pagination for large data154- [ ] **Resource Cleanup**: Close DB connections/file handlers in finally blocks155156### 3. Architecture & Scalability157- [ ] **Design Pattern**: Follow SOLID principles, use Dependency Injection158- [ ] **Modularity**: Decouple logic from UI/Frameworks159160### 4. Observability & Reliability161- [ ] **Logging Standards**: Structured JSON, include trace IDs `request_id`162- [ ] **Metrics**: Track `error_rate`, `latency`, `queue_depth`163- [ ] **Error Handling**: Standardized error codes, no bare except164- [ ] **Observability Artifacts**:165 - **Log Fields**: timestamp, level, message, request_id166 - **Metrics**: request_count, error_count, response_time167 - **Dashboards/Alerts**: High Error Rate > 5%168169170## Agent Directives & Error Recovery171*(ข้อกำหนดสำหรับ AI Agent ในการคิดและแก้ปัญหาเมื่อเกิดข้อผิดพลาด)*172173- **Thinking Process**: Analyze root cause before fixing. Do not brute-force.174- **Fallback Strategy**: Stop after 3 failed test attempts. Output root cause and ask for human intervention/clarification.175- **Self-Review**: Check against Guardrails & Anti-patterns before finalizing.176- **Output Constraints**: Output ONLY the modified code block. Do not explain unless asked.177178179## Definition of Done (DoD) Checklist180181- [ ] Tests passed + coverage met182- [ ] Lint/Typecheck passed183- [ ] Logging/Metrics/Trace implemented184- [ ] Security checks passed185- [ ] Documentation/Changelog updated186- [ ] Accessibility/Performance requirements met (if frontend)187188189## Anti-patterns / Pitfalls190191* ⛔ **Don't**: Log PII, catch-all exception, N+1 queries192* ⚠️ **Watch out for**: Common symptoms and quick fixes193* 💡 **Instead**: Use proper error handling, pagination, and logging194195196## Reference Links & Examples197198* Internal documentation and examples199* Official documentation and best practices200* Community resources and discussions201202203## Versioning & Changelog204205* **Version**: 1.0.0206* **Changelog**:207 - 2026-02-22: Initial version with complete template structure208209---210> Converted and distributed by [TomeVault](https://tomevault.io/claim/amnadtaowsoam) — claim your Tome and manage your conversions.211<!-- tomevault:4.0:skill_md:2026-04-13 -->