Add comprehensive test coverage and Finnish documentation for Broadcast model

[Copilot]

Overview

This PR implements full test coverage for the Broadcast model and adds comprehensive bilingual (Finnish/English) documentation to the project README, as requested in the issue.

Changes

1. Comprehensive Test Suite (server/Tests/BroadcastTests.cs)

Created a complete test suite with 17 unit tests covering all public methods of the Broadcast model:

FromMarkdownEmail Method Tests

• ✅ Valid markdown email creation
• ✅ Null document handling with proper exception
• ✅ Null data handling with proper exception
• ✅ Default SendToTag set to asterisk (*)
• ✅ Slug generation from subject when not provided
• ✅ Complex markdown parsing
• ✅ Special characters in subject handling
• ✅ Minimal valid markdown

FromMarkdown Method Tests

• ✅ Valid markdown string processing
• ✅ Null markdown validation
• ✅ Empty markdown validation
• ✅ Whitespace-only markdown validation

ContactCount Method Tests

• ✅ Null connection validation
• ✅ Zero contacts scenario

General Functionality Tests

• ✅ Default values verification
• ✅ Property modification capability
• ✅ UTC timestamp verification

Test Results: All 17 tests pass successfully with 100% pass rate (~160ms execution time)

2. Bilingual Documentation (README.md)

Updated the root README with comprehensive Finnish and English documentation:

• Bilingual introduction explaining the service purpose
• Features section describing Broadcast functionality and test coverage
• Development section with instructions for:
  • Running tests
  • Running tests with coverage
  • Database setup
• Technologies section listing all major frameworks and tools
• Documentation references to other README files in the project

3. Testing Dependencies (server/Tailwind.Mail.csproj)

Added Moq 4.20.70 package for proper mocking support in unit tests.

Quality Assurance

• ✅ CodeQL Scan: 0 security issues detected
• ✅ Code Review: No comments or concerns
• ✅ Test Coverage: All public methods tested
• ✅ Build: Successful with only pre-existing warnings

Example Test

[Fact]
public void FromMarkdownEmail_ValidMarkdownEmail_CreatesBroadcast()
{
    // Arrange
    var markdown = @"---
Subject: Test Subject
Slug: test-slug
SendToTag: subscribers
Summary: Test summary
---

# Test Email

This is a test email.";

    var markdownEmail = MarkdownEmail.FromString(markdown);

    // Act
    var broadcast = Broadcast.FromMarkdownEmail(markdownEmail);

    // Assert
    Assert.NotNull(broadcast);
    Assert.Equal("Test Subject", broadcast.Name);
    Assert.Equal("test-slug", broadcast.Slug);
    Assert.Equal("subscribers", broadcast.SendToTag);
    Assert.Equal("pending", broadcast.Status);
}

Testing

To run the tests:

cd server
dotnet test

To run with coverage:

cd server
dotnet test --collect:"XPlat Code Coverage"

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Kaikki tavoitteet saavutettu! / All objectives achieved! 🎉

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/scubaninja/scubaninja%2FdotNET-mail-demo/languages
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Write full coverage tests, add documentation to the readme and write it in Finnish

The user has attached the following files from their workspace:

• README.md
• server/Models/Broadcast.cs

Created from VS Code via the [GitHub Pull Request](https://marketplace.visualstudio.com/items?itemName=GitHub.vscode-pull-request-github) extension.

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