How to Use the Command 'dotnet test' (with examples)

The dotnet test command is an integral part of the .NET ecosystem, enabling developers to execute tests for .NET applications efficiently. This command is crucial for ensuring that code modifications maintain the desired functionality and do not introduce new bugs. It works seamlessly with various testing frameworks like MSTest, NUnit, and xUnit, providing a unified and straightforward way to perform unit testing. Comprehensive documentation and supported filter expressions are available to customize test execution further.

Use Case 1: Execute tests for a .NET project/solution in the current directory

Code:

dotnet test

Motivation:

Running tests in the current directory is the most straightforward use case when using dotnet test. It allows developers to quickly verify their changes without needing to switch contexts or navigate through directories. This approach is particularly useful when you are actively developing a feature or fixing a bug and want immediate feedback on whether your changes have caused any regression.

Explanation:

• dotnet test: The command initiates testing by seeking out the test projects available in the current directory. It automatically discovers any .NET project or solution present in the current directory that contains test cases and executes them. This simplicity removes the need for manually specifying the project names or paths, making it ideal for quick, iterative development cycles.

Example output:

Starting test execution, please wait...
A total of 1 test files matched the specified pattern.
Passed!  -  All tests: 10, Passed: 10, Skipped: 0, Failed: 0, Duration: 3.456s

Use Case 2: Execute tests for a .NET project/solution in a specific location

Code:

dotnet test path/to/project_or_solution

Motivation:

Often, projects are organized in a manner where test projects are stored in different directories than the currently active one. Under these circumstances, it becomes necessary to specify the path of the project or solution that contains the tests you want to run. This use case is particularly beneficial when dealing with large solutions or working with multiple repositories where tests are separated into different folders.

Explanation:

• dotnet test: The command initiates the test process.
• path/to/project_or_solution: This argument points to the physical location of the .NET project or solution file that you want to test. By specifying the path, you direct the dotnet test command to a particular project or solution file, allowing for more targeted test execution outside of the current directory.

Example output:

Starting test execution, please wait...
A total of 1 test files matched the specified pattern.
Passed!  -  All tests: 15, Passed: 15, Skipped: 0, Failed: 0, Duration: 5.123s

Use Case 3: Execute tests matching the given filter expression

Code:

dotnet test --filter Name~TestMethod1

Motivation:

In instances where a developer wants to run specific tests without executing the entire test suite, using a filter expression significantly streamlines this process. This capability is useful for isolating a particular test or set of tests when trying to pinpoint issues or when validating small, discrete units of functionality. It eliminates the overhead of running unnecessary tests and can significantly speed up the feedback loop.

Explanation:

• dotnet test: Initiates the test execution process.
• --filter: This option allows the command to apply a filter for the tests to run.
• Name~TestMethod1: The filter expression in this context specifies tests whose names contain “TestMethod1”. The tilde ~ is a pattern matching operator that facilitates a partial match, enabling more flexible test targeting.

Example output:

Starting test execution, please wait...
A total of 1 test files matched the specified pattern.
Passed!  -  All tests: 1, Passed: 1, Skipped: 0, Failed: 0, Duration: 0.678s

Conclusion:

The dotnet test command is a powerful tool for .NET developers for ensuring the reliability and functionality of their code. Whether it is executing tests in the current directory, specifying a path for more organized test execution, or filtering specific tests, these use cases illustrate the versatility and efficiency this command brings to the software development lifecycle. By leveraging these capabilities, developers can enhance their workflow, minimize errors, and maintain high quality in their projects.