Output formats

--format (-f) selects one or more output formats. Each format writes its own file, named after --output-name with the format’s extension appended. The default is traversal.

traversal → affected.proj

An MSBuild Traversal SDK project with one ProjectReference per changed or affected project. This is the format you hand back to dotnet build or dotnet test — see Build and test what changed.

<Project Sdk="Microsoft.Build.Traversal/4.1.82">
  <ItemGroup>
    <ProjectReference Include="/repo/src/DotnetAffected.Abstractions/DotnetAffected.Abstractions.csproj" />
    <ProjectReference Include="/repo/src/DotnetAffected.Core/DotnetAffected.Core.csproj" />
    <ProjectReference Include="/repo/src/dotnet-affected/dotnet-affected.csproj" />
  </ItemGroup>
</Project>

The Traversal SDK version is fixed by the tool, so you don’t need to reference it yourself.

text → affected.txt

One absolute project path per line. Convenient for shell pipelines and for tools that take a file list.

/repo/src/DotnetAffected.Abstractions/DotnetAffected.Abstractions.csproj
/repo/src/DotnetAffected.Core/DotnetAffected.Core.csproj
/repo/src/dotnet-affected/dotnet-affected.csproj

json → affected.json

An indented JSON array with the project name (filename without extension) and its full path.

[
  {
    "Name": "DotnetAffected.Abstractions",
    "FilePath": "/repo/src/DotnetAffected.Abstractions/DotnetAffected.Abstractions.csproj"
  },
  {
    "Name": "DotnetAffected.Core",
    "FilePath": "/repo/src/DotnetAffected.Core/DotnetAffected.Core.csproj"
  }
]

slnf → affected.slnf

A Solution Filter narrowing an existing solution down to the affected projects. Unlike the other formats it references another file, so it needs --filter-file-path pointing at a .sln, .slnx or .slnf:

dotnet affected --filter-file-path Affected.sln --format slnf

{
  "solution": {
    "path": "Affected.sln",
    "projects": [
      "src\\DotnetAffected.Abstractions\\DotnetAffected.Abstractions.csproj",
      "src\\dotnet-affected\\dotnet-affected.csproj",
      "test\\dotnet-affected.Tests\\dotnet-affected.Tests.csproj"
    ]
  }
}

Following the .slnf convention, solution.path is relative to the filter file being written and the project paths are relative to the solution, with backslash separators. That keeps the file usable from any --output-dir, and it opens in Visual Studio like any other solution filter.

When the input is itself a .slnf, the output references the solution behind it, not the input filter — filters never chain.

Asking for slnf without a solution to reference fails while arguments are parsed, before any project is evaluated:

The slnf format needs a Solution to reference. Point --filter-file-path at a Solution (.sln, .slnx) or a Solution Filter (.slnf).

Several formats at once

--format takes a space-separated list, and one file per format is written:

dotnet affected --format text traversal json

WRITE: /repo/affected.txt
WRITE: /repo/affected.proj
WRITE: /repo/affected.json

Every formatter receives the path of the file it is writing and the filter file projects were discovered from, so formats that emit paths — slnf today — stay correct wherever the output goes.

Naming and location

dotnet affected --output-dir ./artifacts --output-name build-set --format text json

writes ./artifacts/build-set.txt and ./artifacts/build-set.json. A relative --output-dir is resolved against --repository-path.

Note

Every format contains both the changed and the affected projects — the two lists that --verbose and describe print separately. There is no format that emits only one of them.

Seeing the output without writing it

--dry-run prints each file’s path and contents to stdout and writes nothing:

dotnet affected --dry-run --format json