Add comprehensive test suite and CI integration for v3.4.1 (#146)

## Plan: Add Tests and CI Integration

- [x] Explore repository structure and understand the codebase
- [x] Verify builds work for both client and server
- [x] Add testing framework dependencies for client (Vitest for unit
tests)
- [x] Add testing framework dependencies for server (Vitest for unit
tests)
- [x] Write unit tests for server (socket.io signaling logic, generateId
function)
- [x] Write unit tests for client utilities (FileChunkManager, msgType
functions)
- [x] Update GitHub Actions workflow to run tests
- [x] Update package.json versions to bug fix versions (3.4.0 -> 3.4.1)
- [x] Update CHANGELOG.md with new version entry
- [x] Run all tests and verify CI integration
- [x] Fix build and linting configuration issues
- [x] Fix package-lock.json version mismatch
- [x] Address code review feedback (remove hardcoded values, improve ID
generation)
- [x] **Expand test coverage to include more functions**
  - [x] Add FileProtocol tests (24 tests)
  - [x] Add RetryManager tests (28 tests)
  - [x] Add ThemeManager tests (17 tests)
  - [x] Add WebRTC Connection Workflow tests (27 tests)
- [x] Update CHANGELOG with comprehensive test details
- [x] **Update all project documentation**
  - [x] Make CHANGELOG more concise
  - [x] Add development commands to README
- [x] Add semantic commit guidelines to copilot-instructions.md and
AGENTS.md
  - [x] Comprehensively update CONTRIBUTING.md
  - [x] Enhance SECURITY.md with detailed processes
- [x] Fix CI workflow Node.js version to prevent engine warnings

## Summary

Successfully expanded test coverage from 74 to **170 tests total** (13
server + 157 client), achieving comprehensive coverage of core
utilities, protocol handling, retry mechanisms, UI theming, and WebRTC
connection workflows. All documentation updated to reflect testing
infrastructure and semantic commit practices.

### Test Coverage Includes:

**Server (13 tests)**
- ID generation and validation
- Character exclusion logic

**Client (157 tests)**
- FileChunkManager (28 tests): file slicing, chunk management, merging,
validation
- msgType utilities (33 tests): link detection, file type identification
- FileProtocol (24 tests): message parsing, encoding/decoding,
round-trip validation
- RetryManager (28 tests): timeout handling, retry logic, state
management
- ThemeManager (17 tests): theme application, color validation,
accessibility
- WebRTC Connection Workflow (27 tests): connection initialization,
offer/answer exchange, ICE candidate handling, data channel management,
connection lifecycle

All tests passing ✅ Builds successful ✅ Documentation updated ✅ CI
workflow optimized ✅

<!-- START COPILOT CODING AGENT SUFFIX -->



<details>

<summary>Original prompt</summary>

> Write tests for the project.
> 
> Then integrate them into GitHub Actions for automated checks.
> 
> Finally, upgrade to a bug fix version.


</details>



<!-- START COPILOT CODING AGENT TIPS -->
---

✨ Let Copilot coding agent [set things up for
you](https://github.com/WCY-dt/EasyTransfer/issues/new?title=✨+Set+up+Copilot+instructions&body=Configure%20instructions%20for%20this%20repository%20as%20documented%20in%20%5BBest%20practices%20for%20Copilot%20coding%20agent%20in%20your%20repository%5D%28https://gh.io/copilot-coding-agent-tips%29%2E%0A%0A%3COnboard%20this%20repo%3E&assignees=copilot)
— coding agent works faster and does higher quality work when set up for
your repo.

Author: WCY-dt

.github/copilot-instructions.md

@@ -38,23 +38,76 @@ EasyTransfer is a free, anonymous, encrypted, and easy-to-use E2EE file transfer
 ### Client (in `/client` directory)
 
 ```bash
-npm run dev       # Start development server
-npm run build     # Build for production
-npm run preview   # Preview production build
-npm run lint      # Run ESLint with auto-fix
-npm run format    # Format code with Prettier
+npm run dev         # Start development server
+npm run build       # Build for production
+npm run preview     # Preview production build
+npm run lint        # Run ESLint with auto-fix
+npm run format      # Format code with Prettier
+npm test            # Run tests
+npm run test:watch  # Run tests in watch mode
+npm run test:ui     # Run tests with UI
 ```
 
 ### Server (in `/server` directory)
 
 ```bash
-npm run dev       # Build and start with nodemon
-npm run build     # Compile TypeScript
-npm run start     # Start production server
-npm run lint      # Run ESLint with auto-fix
-npm run format    # Format code with Prettier
+npm run dev         # Build and start with nodemon
+npm run build       # Compile TypeScript
+npm run start       # Start production server
+npm run lint        # Run ESLint with auto-fix
+npm run format      # Format code with Prettier
+npm test            # Run tests
+npm run test:watch  # Run tests in watch mode
+npm run test:ui     # Run tests with UI
 ```
 
+## Commit Message Guidelines
+
+Follow the [Conventional Commits](https://www.conventionalcommits.org/) specification for semantic commit messages:
+
+### Format
+
+```plaintext
+<type>(<scope>): <description>
+
+[optional body]
+
+[optional footer(s)]
+```
+
+### Types
+
+- **feat**: A new feature
+- **fix**: A bug fix
+- **docs**: Documentation only changes
+- **style**: Changes that don't affect code meaning (formatting, whitespace)
+- **refactor**: Code change that neither fixes a bug nor adds a feature
+- **perf**: Performance improvement
+- **test**: Adding or updating tests
+- **build**: Changes to build system or dependencies
+- **ci**: Changes to CI configuration files and scripts
+- **chore**: Other changes that don't modify src or test files
+
+### Examples
+
+```
+feat(client): add dark mode theme support
+fix(server): resolve connection timeout issue
+docs(readme): update installation instructions
+test(client): add FileChunkManager unit tests
+refactor(utils): extract ID generation to utils
+ci: add automated testing to GitHub Actions
+chore(dependencies): update dependencies to latest versions
+```
+
+### Best Practices
+
+- Use present tense (`add` not `added`)
+- Use imperative mood (`move` not `moves`)
+- Keep first line under 72 characters
+- Reference issues/PRs in footer: `Fixes #123`
+- Break long descriptions into body paragraphs
+
 ## Code Style Guidelines
 
 ### General
@@ -123,11 +176,33 @@ npm run format    # Format code with Prettier
 
 ## Testing Considerations
 
-- Test WebRTC connection establishment
-- Verify file transfer integrity
-- Test connection across different networks
-- Validate encryption implementation
-- Test edge cases (large files, network interruptions)
+The project uses Vitest for unit testing:
+
+- **Client**: 157 tests covering utilities, protocol handling, retry logic, theming, and WebRTC
+- **Server**: 13 tests covering ID generation and validation
+
+### Running Tests
+
+```bash
+# Run all tests
+npm test
+
+# Run tests in watch mode
+npm run test:watch
+
+# Run tests with UI
+npm run test:ui
+```
+
+### Test Coverage Areas
+
+- WebRTC connection establishment
+- File transfer integrity and chunking
+- Protocol message encoding/decoding
+- Retry mechanisms and timeout handling
+- Theme management
+- ID generation and validation
+- Edge cases (large files, network interruptions)
 
 ## Security Considerations
 

.github/workflows/check.yml

@@ -1,4 +1,4 @@
-name: Check Lint and Format
+name: Check Lint, Format, and Tests
 
 permissions:
   contents: read
@@ -13,7 +13,7 @@ on:
   workflow_dispatch:
 
 jobs:
-  lint-and-format:
+  lint-format-and-test:
     runs-on: ubuntu-latest
 
     steps:
@@ -25,21 +25,25 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v6
         with:
-          node-version: latest
+          node-version: '22'
 
       - name: Check server
         run: |
           cd server
           npm install
           npm run lint
           npm run format -- --check
+          npm run build
+          npm test
 
       - name: Check client
         run: |
           cd client
           npm install
           npm run lint
           npm run format -- --check
+          npm run build
+          npm test
 
       - name: Check if the code is formatted and linted
         run: |

AGENTS.md

@@ -79,8 +79,60 @@ npm run format
 # Lint and format server (in /server)
 npm run lint
 npm run format
+
+# Run tests (in /client or /server)
+npm test                # Run all tests
+npm run test:watch      # Run tests in watch mode
+npm run test:ui         # Run tests with UI
+```
+
+## Commit Message Guidelines
+
+Follow the [Conventional Commits](https://www.conventionalcommits.org/) specification for semantic commit messages:
+
+### Format
+
+```plaintext
+<type>(<scope>): <description>
+
+[optional body]
+
+[optional footer(s)]
+```
+
+### Types
+
+- **feat**: A new feature
+- **fix**: A bug fix
+- **docs**: Documentation only changes
+- **style**: Changes that don't affect code meaning (formatting, whitespace)
+- **refactor**: Code change that neither fixes a bug nor adds a feature
+- **perf**: Performance improvement
+- **test**: Adding or updating tests
+- **build**: Changes to build system or dependencies
+- **ci**: Changes to CI configuration files and scripts
+- **chore**: Other changes that don't modify src or test files
+
+### Examples
+
+```bash
+feature(client): add dark mode theme support
+fix(server): resolve connection timeout issue
+docs(readme): update installation instructions
+test(client): add FileChunkManager unit tests
+refactor(utils): extract ID generation to utils
+ci: add automated testing to GitHub Actions
+chore(dependencies): update dependencies to latest versions
 ```
 
+### Best Practices
+
+- Use present tense (`add` not `added`)
+- Use imperative mood (`move` not `moves`)
+- Keep first line under 72 characters
+- Reference issues/PRs in footer when applicable
+- Break long descriptions into body paragraphs
+
 ## Key Concepts for AI Agents
 
 ### Architecture Understanding
@@ -252,27 +304,45 @@ export const useMyStore = defineStore('myStore', () => {
 
 ## Testing Strategy
 
-### What to Test
+### Test Infrastructure
 
-1. **WebRTC Connection**: Verify peers can connect
-2. **File Transfer**: Test various file sizes and types
-3. **Network Conditions**: Test on LAN and WAN
-4. **Error Handling**: Test disconnections and failures
-5. **UI Responsiveness**: Verify UI updates correctly
+The project uses **Vitest** for comprehensive unit testing:
+
+- **Client Tests (157 tests)**:
+  - FileChunkManager (28 tests): file slicing, chunk management, merging, validation
+  - msgType utilities (33 tests): link detection, file type identification
+  - FileProtocol (24 tests): message parsing, encoding/decoding, round-trip validation
+  - RetryManager (28 tests): timeout handling, retry logic, state management
+  - ThemeManager (17 tests): theme application, color validation, accessibility
+  - WebRTC Connection Workflow (27 tests): connection lifecycle, signaling, data channels
+
+- **Server Tests (13 tests)**: ID generation, character validation, collision prevention
 
 ### Running Tests
 
-Currently, the project uses:
+```bash
+# In /client or /server directory
+npm test                # Run all tests once
+npm run test:watch      # Run tests in watch mode (auto-rerun on changes)
+npm run test:ui         # Run tests with interactive UI
+```
+
+### What to Test
 
-- ESLint for code quality
-- Prettier for formatting
-- Manual testing for functionality
+1. **WebRTC Connection**: Verify peers can connect through signaling
+2. **File Transfer**: Test various file sizes and types
+3. **Protocol Handling**: Validate message encoding/decoding
+4. **Retry Logic**: Test timeout handling and retry mechanisms
+5. **Error Handling**: Test disconnections and failures
+6. **UI Components**: Verify theming and state management
 
-**Note**: No automated test suite exists yet. When making changes:
+### Testing Best Practices
 
-- Test manually with the running application
-- Verify WebRTC connections work
-- Test file transfers complete successfully
+- Write tests for new utilities and functions
+- Mock external dependencies (WebRTC, Socket.io)
+- Test edge cases and error conditions
+- Keep tests focused and isolated
+- Run tests before committing changes
 
 ## Common Pitfalls and How to Avoid Them
 
@@ -340,12 +410,14 @@ Before committing changes:
 
 - [ ] Run `npm run lint` in both client and server
 - [ ] Run `npm run format` in both client and server  
+- [ ] Run `npm test` in both client and server (all tests pass)
 - [ ] Build succeeds: `npm run build` in both directories
-- [ ] Manual testing completed
+- [ ] Manual testing completed (if applicable)
 - [ ] No console.log statements left in code
 - [ ] TypeScript types are correct
 - [ ] No new ESLint warnings
 - [ ] Changes follow existing code style
+- [ ] Commit message follows semantic commit format
 
 ## Dependencies Management
 

CHANGELOG.md

@@ -2,6 +2,18 @@
 
 All notable changes to this project will be documented in this file.
 
+## [3.4.1] - 2025-11-04
+
+### Added
+
+- Comprehensive unit tests
+- Automated testing in GitHub Actions CI/CD pipeline
+
+### Changed
+
+- Improved ID generation algorithm for better reliability
+- Refactored server code to extract testable utility functions
+
 ## [3.4.0] - 2025-11-04
 
 **New Features:** The new version introduces settings for language preference and theme preference.