How to Run Selenium Tests With C# on TestMu AI

Run your C# Selenium tests on the TestMu AI cloud grid across 10,000+ browser/device combinations. The setup is the same for every framework: you connect to the grid and pass your capabilities. This guide covers that shared flow once, then gives you a per-framework quickstart in the tabs below.

Prerequisites

Complete these before running any framework below.

Create a TestMu AI account if you don't have one.
Get your Username and Access Key from the TestMu AI Dashboard.
Install the .NET Core SDK 2.1 or later (MSTest needs 3.0.0).
Install the Selenium WebDriver C# bindings.

Set Your Credentials

Every framework authenticates the same way: your Username and Access Key are read from environment variables. Set them once. Pick your operating system:

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macOS / Linux
Windows (CMD)

export LT_USERNAME="undefined"
export LT_ACCESS_KEY="undefined"

set LT_USERNAME=undefined
set LT_ACCESS_KEY=undefined

How the Sample Test Works

Every framework below connects to the grid and passes your browser and OS choices through an LT:Options object:

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var browserOptions = new ChromeOptions();
browserOptions.PlatformName = "Windows 10";
browserOptions.BrowserVersion = "latest";

var ltOptions = new Dictionary<string, object>
{
    { "username", LT_USERNAME },
    { "accessKey", LT_ACCESS_KEY },
    { "project", "Demo LT" },
    { "w3c", true }
};
browserOptions.AddAdditionalOption("LT:Options", ltOptions);

What changes between frameworks is only the test runner and how you launch it. That is what each tab covers.

tip

Use the Capabilities Generator to build an LT:Options block for any browser, version, and OS combination.

Run a Test in Your Framework

Each tab lists the framework-specific pieces. Clone the matching repo (it contains the full, ready-to-run project), then build and run.

NUnit
MSTest
SpecFlow
xUnit
Reqnroll

NUnit runs from the Visual Studio Test Explorer, or from the CLI on Linux/macOS.

Clone the sample GitHub project:

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git clone https://github.com/LambdaTest/CSharp-NUnit-Selenium
cd CSharp-NUnit-Selenium

Set your browser and OS in the LT:Options object:

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var browserOptions = new ChromeOptions();
browserOptions.PlatformName = "Windows 10";
browserOptions.BrowserVersion = "latest";

var ltOptions = new Dictionary<string, object>
{
    { "build", "NUnit Build" },
    { "name", "NUnit Test" },
    { "w3c", true }
};
browserOptions.AddAdditionalOption("LT:Options", ltOptions);

Build the solution, then run in the Test Explorer, or on Linux/macOS:

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dotnet test

The test then appears on the Automation Dashboard. A green status confirms it passed.

MSTest requires .NET Core SDK 3.0.0 and runs via dotnet test or the Test Explorer.

Clone the sample GitHub project:

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git clone https://github.com/LambdaTest/MSTest-Selenium-Sample
cd MSTest-Selenium-Sample

Set your browser and OS in the LT:Options object:

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var browserOptions = new ChromeOptions();
browserOptions.PlatformName = "Windows 10";
browserOptions.BrowserVersion = "latest";

var ltOptions = new Dictionary<string, object>
{
    { "build", "MSTest Build" },
    { "name", "MSTest Test" },
    { "w3c", true }
};
browserOptions.AddAdditionalOption("LT:Options", ltOptions);

Run the test:

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dotnet test MS-Test-Cross-Browser.csproj

The test then appears on the Automation Dashboard. A green status confirms it passed.

Deprecated

SpecFlow is no longer actively maintained. For current C# BDD testing, use the Reqnroll framework instead (see the Reqnroll tab), its actively-maintained open-source successor.

SpecFlow is BDD for .NET: you write Gherkin feature files, and step definitions drive WebDriver. Requires SpecFlow installed.

Clone the sample GitHub project:

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git clone https://github.com/LambdaTest/SpecFlow-Selenium-Sample
cd SpecFlow-Selenium-Sample

Set your browser and OS in the LT:Options object:

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var browserOptions = new ChromeOptions();
browserOptions.PlatformName = "Windows 10";
browserOptions.BrowserVersion = "latest";

var ltOptions = new Dictionary<string, object>
{
    { "build", "SpecFlow Build" },
    { "name", "SpecFlow Test" },
    { "w3c", true }
};
browserOptions.AddAdditionalOption("LT:Options", ltOptions);

Build the solution, then run in the Test Explorer (use Run All for parallel tests).

The test then appears on the Automation Dashboard. A green status confirms it passed.

xUnit reads its capabilities and environments from a config.json, filtered by profile.

Clone the sample GitHub project:

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git clone https://github.com/LambdaTest/CSharp-xUnit-Selenium
cd CSharp-xUnit-Selenium

Set your browsers in config.json. Replace the user and key values with your actual credentials, or have them read from the LT_USERNAME and LT_ACCESS_KEY environment variables you set earlier:

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config.json
{
  "server": "hub.lambdatest.com",
  "user": "LT_USERNAME",
  "key": "LT_ACCESS_KEY",
  "capabilities": {
    "lt:options": {
      "buildName": "xunit build",
      "sessionName": "lambdatest xunit sample test",
      "visual": "true",
      "plugin": "xunit:sample"
    }
  },
  "environments": [
    { "browserName": "chrome" },
    { "browserName": "firefox" },
    { "browserName": "safari" }
  ],
  "TunnelOptions": { "tunnel": false }
}

Run a single test, or the parallel profile:

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dotnet clean
dotnet test --filter "profile=single"
dotnet test --filter "profile=parallel"

The test then appears on the Automation Dashboard. A green status confirms it passed.

Reqnroll is the actively-maintained, open-source successor to SpecFlow. It is a BDD framework for .NET: you write Gherkin feature files, and step definitions drive WebDriver. Requires Reqnroll and a .NET Core SDK 2.1 or greater installed.

Clone the sample GitHub project:

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git clone https://github.com/LambdaTest/reqnroll-automation-sample
cd reqnroll-automation-sample

Set your browser and OS, and your credentials, in the Makefile, or export them as the LT_USERNAME and LT_ACCESS_KEY environment variables you set earlier.
Build and run the tests using the project Makefile:

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make clean
make build
make reqnroll-automation-test

The test then appears on the Automation Dashboard. A green status confirms it passed.

View Your Results

Your test results appear on the TestMu AI Automation Dashboard.

Your test results, including video, network logs, and command-by-command execution, appear on the TestMu AI Automation Dashboard.

Next steps: If this is your first run, walk through running your first Selenium test end to end. From there, explore the full set of Selenium automation capabilities you can pass to the grid, learn how to debug your Selenium tests, and organize and filter your Selenium tests as your suite grows.