07 Development

Development

This page is for contributors and anyone building MQTTProbe from source. For the contribution workflow (issues, PRs, git hooks, style, CI), see CONTRIBUTING.md.

Prerequisites

• .NET 10 SDK
• MAUI workload only if you are building the MAUI targets (Android, Windows MAUI)
• Python 3 for the helper scripts (coverage, format check)

Clone with submodules

The repo includes SparkplugNet as a git submodule. Clone with submodules from the start:

git clone --recurse-submodules https://github.com/bluegrassiot/mqttprobe.git

If you already cloned without that flag:

git submodule update --init --recursive

Solution layout

Project	Path	Role
MqttProbe.Shared	src/MqttProbe.Shared	Shared UI (Blazor components), models, services. This is where most of the application logic lives.
MqttProbe.Web	src/MqttProbe.Web	ASP.NET Core web host. Used for the web deployment and Docker image.
MqttProbe.Maui	src/MqttProbe.Maui	MAUI host for Android and Windows MAUI builds.
MqttProbe.Desktop	src/MqttProbe.Desktop	Photino desktop host for Linux and macOS desktop builds.
MqttProbe.Tests	tests/MqttProbe.Tests	Unit and integration tests.
MqttProbe.Benchmarks	benchmarks/MqttProbe.Benchmarks	Standalone MQTT payload publisher for load/format testing against a real broker (not unit tests).

The main solution file is MqttProbe.slnx at the repo root. A filter solution MqttProbe.NoMaui.slnf excludes the MAUI project for faster builds when you do not need MAUI targets.

Key libraries

• MQTTnet 5.x with an in-house managed client wrapper that handles reconnect, resubscribe, and message queuing. The wrapper lives under src/MqttProbe.Shared/Services/Mqtt/.
• MudBlazor for the UI component library.
• SparkplugNet (submodule): see SparkplugNet fork below.
• Protobuf generation as needed for Sparkplug and protocol schemas.
• Blazor-ApexCharts for message and topic visualizations.

SparkplugNet fork

MQTTProbe uses SparkplugNet for Sparkplug B encoding and decoding. The original library by SeppPenner is published on NuGet, but it still targets the MQTTnet v4 era. Since MQTTProbe runs on MQTTnet 5.2.x, we maintain a fork that ports SparkplugNet onto the newer MQTTnet version.

	Repo
Upstream	https://github.com/SeppPenner/SparkplugNet
Fork (used here)	https://github.com/bluegrassiot/SparkplugNet

The fork lives at external/SparkplugNet as a git submodule and is consumed as a project reference from the submodule (see the comment in MqttProbe.Shared.csproj), not the NuGet package. Clone with --recurse-submodules to pull it automatically (see Clone with submodules above).

Credit to SeppPenner for the original work. The fork is purely for MQTTnet 5 compatibility maintenance.

Benchmarks

The benchmarks project publishes realistic multi-format payloads (Sparkplug, JSON, MessagePack, hex, and others) to a broker so you can exercise MQTTProbe's decode and UI paths under load. It is a standalone tool built on MQTTnet 5.2 and does not depend on MqttProbe.Shared (except for linked Sparkplug protobuf sources). It is included in the main MqttProbe.slnx solution.

Quick run:

dotnet run --project benchmarks/MqttProbe.Benchmarks -c Release -- publish

Optional flags to control volume and format:

dotnet run --project benchmarks/MqttProbe.Benchmarks -c Release -- publish --count 500 --rate 200 --format Sparkplug,Json

For the full list of options, see benchmarks/MqttProbe.Benchmarks/README.md.

Common commands

Run the test suite:

dotnet test tests/MqttProbe.Tests

Launch the web project with hot reload:

dotnet watch --project src/MqttProbe.Web

Check code coverage (writes a report under coverage/):

python scripts/coverage.py

Check C# and Razor formatting:

python scripts/format-check.py

Auto-fix formatting issues:

python scripts/format-check.py --fix

Contributing

For the full contribution workflow, including how to report issues, open PRs, set up git hooks, code style, and CI pipeline details, see CONTRIBUTING.md.