Running .NET Tests in a Docker Container

--- title: Run .NET tests in a container linkTitle: Run your tests weight: 30 keywords: .NET, test description: Learn how to run your .NET tests in a container. aliases: - /language/dotnet/run-tests/ - /guides/language/dotnet/run-tests/ --- ## Prerequisites Complete all the previous sections of this guide, starting with [Containerize a .NET application](containerize.md). ## Overview Testing is an essential part of modern software development. Testing can mean a lot of things to different development teams. There are unit tests, integration tests and end-to-end testing. In this guide you take a look at running your unit tests in Docker when developing and when building. ## Run tests when developing locally The sample application already has an xUnit test inside the `tests` directory. When developing locally, you can use Compose to run your tests. Run the following command in the `docker-dotnet-sample` directory to run the tests inside a container. ```console $ docker compose run --build --rm server dotnet test /source/tests ``` You should see output that contains the following. ```console Starting test execution, please wait... A total of 1 test files matched the specified pattern. Passed! - Failed: 0, Passed: 1, Skipped: 0, Total: 1, Duration: < 1 ms - /source/tests/bin/Debug/net8.0/tests.dll (net8.0) ``` To learn more about the command, see [docker compose run](/reference/cli/docker/compose/run/). ## Run tests when building To run your tests when building, you need to update your Dockerfile. You can create a new test stage that runs the tests, or run the tests in the existing build stage. For this guide, update the Dockerfile to run the tests in the build stage. The following is the updated Dockerfile. ```dockerfile {hl_lines="9"} # syntax=docker/dockerfile:1 FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:8.0-alpine AS build ARG TARGETARCH COPY . /source WORKDIR /source/src RUN --mount=type=cache,id=nuget,target=/root/.nuget/packages \ dotnet publish -a ${TARGETARCH/amd64/x64} --use-current-runtime --self-contained false -o /app

This section guides you through running .NET unit tests within a Docker container, both during local development and as part of the build process. It assumes you have already containerized a .NET application as described in previous sections. The guide uses Compose to execute tests locally and modifies the Dockerfile to include a test execution step during the build.