Running JustMock Elevated Unit Tests with Docker

You can run .NET Framework and .NET Core unit tests in Docker with either docker build or docker run commands. Running tests as a part of docker build provides an early feedback for pass/fail results printed the the console output. The other approach docker run is useful of getting complete test results (trx) captured with volume mounting.

Prepare required JustMock stuff

Please perform the following actions either manually or by employing a script file:

1. Determine the JustMock installation path from the system registry.
2. Copy the necessary binaries and profiler files to a specified local directory.
3. Prepare a clean environment for conducting tests using JustMock.

Note: Ensure that the binaries and paths specified in your project file match those prepared during the containerization process.

Build your Dockerfile

1. Use a base image that aligns with the requirements of your framework and operating system.

2. Set up the necessary environment variables.

ENV JUSTMOCK_BINARY_PATH /justmock
ENV TELERIK_LICENSE=your_license_key

1. Copy required binaries and libraries.

COPY JustMock/Telerik.JustMock.dll /justmock/
COPY JustMock/CodeWeaver/32/Telerik.CodeWeaver.Profiler.dll /justmock/codewaver/32/
COPY JustMock/CodeWeaver/64/Telerik.CodeWeaver.Profiler.dll /justmock/codewaver/64/
COPY JustMock/Telerik.JustMock.Console.exe /justmock/

1. Use dotnet restore and dotnet build to prepare your code.

WORKDIR /build
COPY *.sln .
COPY MyClassLibrary/*.csproj ./MyClassLibrary/
COPY MyClassLibrary.Test/*.csproj ./MyClassLibrary.Test/
WORKDIR /build
RUN dotnet restore

WORKDIR /build
COPY . .
RUN dotnet build

1. You can run tests using the JustMock.Console.

WORKDIR /build
RUN ["/justmock/Telerik.JustMock.Console.exe", "runadvanced",\
 "--profiler-path-32", "/justmock/codewaver/32/Telerik.CodeWeaver.Profiler.dll",\
 "--profiler-path-64", "/justmock/codewaver/64/Telerik.CodeWeaver.Profiler.dll",\
 "--command", "dotnet",\
 "--command-args", "test --logger:\"console;verbosity=detailed\""]

1. Optionally, you can define a second stage in your Dockerfile to create a lightweight image for running tests.

FROM sdk AS testrunner
WORKDIR /build
ENTRYPOINT ["/justmock/Telerik.JustMock.Console.exe", "runadvanced",\
 "--profiler-path-32", "/justmock/codewaver/32/Telerik.CodeWeaver.Profiler.dll",\
 "--profiler-path-64", "/justmock/codewaver/64/Telerik.CodeWeaver.Profiler.dll",\
 "--command", "dotnet",\
 "--command-args", "test /logger:trx ./MyClassLibrary.Test/bin/Debug/net472/MyClassLibrary.Test.dll"]

Getting the sample

Download the sample zip and extract it.

Run unit tests as part of docker build

You can run unit tests as part of docker build, using the following commands, the instructions assume that you are in the root directory of the sample.

call prepare.bat
docker build --target testrunner -t jmsample:test .

You can play a little bit with the test sources, so that you can see the behavior when that happens as part of docker build. Open .\MySolution\MyClassLibrary.Test\UnitTest1.cs and modify the test as it shown below:

[TestMethod]
public void TestMethod1()
{
    // Arrange
    var sut = Mock.Create<Class1>();
    int expected = 5;
    Mock.Arrange(() => sut.Method1(Arg.AnyInt)).Returns(expected);

    // Act 
    int actual = sut.Method1(10);

    // Assert
    Assert.AreEqual(actual, 10);
}

Than, rerun docker build so that you can see the failure.

Run unit tests as part of docker run

Now you can use previously built image with docker build command to run the tests by just running the container. The sample Dockerfile includes a testrunner stage with a separate ENTRYPOINT command, which executes the unit tests in elevated mode. The following command uses volume mounting to enable the test runner to write test log files to your local drive.

docker run --rm -v "%CD%\TestResults:C:\build\TestResults" -it jmsample:test

Reading the Results

You should be able to find a .trx file in the TestResults folder. You can open this file in Visual Studio.

More Samples

You can find more samples for using Docker with .NET here:

• .NET Framework Console Docker Sample
• .NET Core Docker Samples