Wolfgang.Extensions.Logging.InMemoryLogger

An implementation of ILogger and ILogger<T> from Microsoft.Extensions.Logging that writes log entries to an in-memory collection. Designed for unit and integration tests where you need to assert against logged messages.

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📦 Installation

dotnet add package Wolfgang.Extensions.Logging.InMemoryLogger

NuGet Package: Wolfgang.Extensions.Logging.InMemoryLogger

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📄 License

This project is licensed under the MIT License. See the LICENSE file for details.

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📚 Documentation

• GitHub Repository: https://github.com/Chris-Wolfgang/In-memory-Logger
• API Documentation: https://Chris-Wolfgang.github.io/In-memory-Logger/
• CHANGELOG: CHANGELOG.md
• Contributing Guide: CONTRIBUTING.md
• DocFX Version Picker Troubleshooting: docs/DOCFX-VERSION-PICKER.md

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✨ Features

• Thread-safe in-memory log entry storage.
• Configurable minimum log level (passed to the constructor; defaults to LogLevel.Trace).
• Configurable initial capacity (defaults to 16).
• Supports all .NET log levels (Trace through Critical).
• Captures scope state via BeginScope for assertion in tests.
• Returns log entries as IReadOnlyList<LogEntry<object>> for easy LINQ + assertion patterns.
• Ships both a non-generic InMemoryLogger (constructed with a category string) and a generic InMemoryLogger<T> (category derived from typeof(T)), matching the standard ILogger / ILogger<T> shape.

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🚀 Quick Start

using Microsoft.Extensions.Logging;
using Wolfgang.Extensions.Logging.InMemoryLogger;

// Generic form — category is "MyApp.MyService"
var logger = new InMemoryLogger<MyService>(LogLevel.Information);

// Use the logger in code under test
var service = new MyService(logger);
service.DoWork();

// Assert against captured log entries
Assert.Single(logger.LogEntries);
Assert.Equal(LogLevel.Information, logger.LogEntries[0].LogLevel);

The non-generic form takes a category string directly:

var logger = new InMemoryLogger("MyCategory", LogLevel.Warning, capacity: 32);

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🎯 Supported Frameworks

This library targets:

• .NET Framework: 4.6.2
• .NET Standard: 2.0, 2.1
• .NET: 8.0, 10.0

See the NuGet package page for the authoritative per-TFM compatibility matrix.

🔍 Code Quality & Static Analysis

This project is held to the canonical analyzer set used across all Chris-Wolfgang .NET libraries. Analyzers run on every build and are treated as errors in Release.

Analyzers in Use

1. Microsoft.CodeAnalysis.NetAnalyzers — built-in .NET analyzers (correctness and performance)
2. Roslynator.Analyzers — refactoring and code quality
3. AsyncFixer — async/await best practices
4. Microsoft.VisualStudio.Threading.Analyzers — thread safety
5. Microsoft.CodeAnalysis.BannedApiAnalyzers — enforces the BannedSymbols.txt policy
6. Meziantou.Analyzer — broad code-quality rules
7. SonarAnalyzer.CSharp — industry-standard analysis
8. Microsoft.CodeAnalysis.PublicApiAnalyzers — public-API surface tracking via PublicAPI.Shipped.txt / PublicAPI.Unshipped.txt

Banned-API policy

BannedSymbols.txt is the canonical fleet baseline. Banned categories include blocking sync-over-async (Task.Result, Task.Wait()), Thread.Sleep, synchronous file I/O, and several legacy / deprecated APIs.

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🤝 Contributing

Contributions are welcome! Please see CONTRIBUTING.md for:

• Code quality standards
• Build and test instructions
• Pull request guidelines
• Analyzer configuration details