Coveralls vs Microsoft Code Coverage

Coveralls analyzes software test coverage, showing teams which code is not covered by tests. Its dashboard presents project coverage percentages and their changes over time, while repository views drill down from a project to sub-projects, files, and individual lines. Build history tracks coverage across branches, including pull requests. Coveralls can add summarized coverage results to pull requests and send status updates that apply coverage criteria to merge decisions. Notifications can go to Slack or webhooks. It supports line and branch coverage, with report formats including LCOV, SimpleCov, Cobertura, JaCoCo, and Clover XML. Coveralls says it works with any CI service and lists more than 30 community-created integrations, a GitHub Action, and a CircleCI Orb. An API can add repositories programmatically and return recent build statistics. Open-source and public repositories are free. The Starter plan is $10 a month for one private repository and includes a 30-day trial. A self-hosted enterprise installation can operate within existing security controls without outbound network access.

Microsoft Code Coverage measures how much of a project’s code is exercised by coded tests, such as unit tests. Its documented workflows cover.NET test projects with `dotnet test` and other.NET applications with the `dotnet-coverage` tool. It analyzes managed CLR and unmanaged native code using static or dynamic instrumentation; native coverage is disabled by default in the MTP extension. With Microsoft.Testing.Platform.MSBuild, extensions are auto-registered with MSTest, NUnit, and xUnit runners. The MTP extension can produce coverage, XML, and Cobertura reports, with settings for output, inclusion and exclusion rules, and instrumentation. It runs on Windows, macOS, and multiple Linux distributions, though instrumentation support varies by OS, version, and architecture. Other operating systems are supported on a best-effort basis, and some combinations allow static instrumentation only. Dynamic instrumentation on macOS and Linux requires libxml2, and missing dependencies may leave a report empty. MTP also excludes test assemblies by default unless configured otherwise. The plan is free.