Hello, I am Laszlo

Choosing Package Dependencies

03/12/2024

Applications today are built upon well-tested, reusable packages. These packages solve the most common aspects of software development, such as logging, authentication, handling HTTP requests, serialization etc.

It is a regular task for a development team to decide which dependency to take on. New features will be built-up these dependencies. A new dependency is an additional responsibility for team: updating and replacing the package without breaking the features built on it. Updating non-breaking or patch releases is a straightforward task, however replacing a library or updating it with breaking changes can be extremely costly. I have come across teams stuck with no longer maintained libraries for years, before the team managed to completely get rid of it. Any security vulnerabilities during this period pose a risk. Therefore, the decision for picking the right library has a huge weight.

I very often observe teams deciding application dependencies based on the packages' popularity. I think this is a fraud way of picking libraries. In this post I summarize the questions that I prefer to ask when I have to introduce a new dependency in an application. I expand on my questions in the space of .NET, C# and NuGet packages. I know some of the languages are vastly different to the NuGet package ecosystem, for example npm is has more and tiny packages. Developers of such ecosystems might take my concerns with a grain of salt and apply that best works for them.

NuGet Packages

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Stable and Unstable Sorts in .NET

03/09/2024

Sorting items of a collection is a common task that .NET developers perform. A collection is a data structure that stores multiple values, such as an array, a list, a dictionary, etc.

One common way to sort items of a collection in .NET 8 (and previous .NET versions) is by using LINQ’s OrderBy extension method. LINQ stands for Language Integrated Query, and it is a set of features that allow you to query and manipulate data in various ways. For example, you can use OrderBy to sort a list of names alphabetically:

// Create a list of names
List<string> names = new List<string>() { "Charlie", "Alice", "Bob" };

// Sort the list by name using OrderBy
var sortedNames = names.OrderBy(name => name);

Another way to sort items of a collection is by using Array.Sort method. This method works on arrays, which are fixed-size collections of values. For example, you can use Array.Sort to sort an array of numbers in ascending order:

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Building an IAQ device with Meadow

02/17/2024

Indoor air quality (IAQ) is increasingly important for our health, productivity and well-being. The industrialized world suffers from air pollution, and buildings are no exceptions. A room's air might be filled with pollutants such as bacteria, carbon monoxide or carbon dioxide.

Meadow is a microcontroller that can run C# code. It is designed by Wilderness Labs. Meadow can be attached to a Project Lab, which is a functional IoT prototyping platform. It has numerous sensors built-in, buttons, a screen and a wide variety of connectors.

One particular sensor on the Project Lab board is the BME688 manufactured by Bosch. This sensor is interesting as besides the regular temperature, pressure, humidity, it can measure gas resistance. It is a metal oxide-based sensor that can detect gases by adsorption on its sensitive layer. It also comes with a software library, which can distinguish the different gases using AI. It can detect Volatile Organic Compounds (VOCs), Volatile Sulfur Compounds (VSCs), carbon monoxide and carbon dioxide.

The sensor also comes with an AI feature and a comprehensive SDK that enable developers to design and customize its behavior to their use-case. One such example I found online is the Cheese vs. Meat detector.

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Calculating U.S. Treasury Notes Pricing

01/28/2024

A few years ago, I worked on a type that could process double values received as real-time market data updates and helped to convert them to be displayed for humans on a UI.

The type was used to process market data updates of U.S. Treasury Notes. The pricing of U.S. Treasury Notes is detailed on the cmegroup site. In this post I will focus on the pricing of bond and note products while keeping futures aside.

The prices of these products are displayed in fractions. The price of such a product may look as 99-032. This means it is 99 full points plus 3/32s of a point plus 2/8 of 1/32s of a point. The last digit of the price can take up values of 0 2, + and 6, where plus denotes 4/8 or 1/2.Hence 99-032 equals 99 + 3/32 + 2/256 = 99.1015625. Note, that the last digit is always a multiple of 1/4th of a 1/32nd. Another example may be 100-23+ which equals 100.734375. However, this post will focus on displaying such data, converting it from a double such as 100.734375 to 100-23+.

A few years back .NET was less performant. In this post, I will revisit the original implementation as well as review 3 implementations I would consider building today to take advantage of the performance benefits of the modern .NET. Even the original implementation is significantly faster when run on .NET 8 due to the number of optimizations that have been built into the BCL and the JIT.

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Using NDepend to improve my Application Code

01/18/2024

NDepend is a .NET code quality tool that performs static code analysis. It can help to detect code smells and dependency issues. In this post I will take a quick look at using the Dependency Graph feature to clean up one of my open-source applications. NDepend has a desktop application (as well as Visual Studio extension) that can be used by developers in a tight development cycle to address dependency and code quality issues during development:

• change code

• build application

• run analysis (or configure automatic analysis in NDepend for every build)

The tool also comes with a handy console application that can be leveraged for enforce quality rules on CI/CD agents. Later in this post I look at generating reports with the NDepend Console on build agents.

Dependency Graph

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