How should we handle not having any changes?

[leonardochaia]

Currently the tool just outputs nothing:

dotnet affected generate --verbose --output /tmp/tobuild.proj --to <redacted> --from <redacted>

Finding all csproj at /var/jenkins_home/workspace/<redacted>

Building Dependency Graph

Found 92 projects

Finding changes from <redacted> against <redacted>

Found 24 changed files inside 0 projects.

Files inside these projects have changed:

These projects are affected by those changes:

Generating Traversal SDK Project

Creating file at /tmp/tobuild.proj

Should we exit with > 0?

At least improve presentation messages

[wterpstra]

Generally a non-zero exit code means an error of some sort. However, that is not necessarily the case here. So I guess add some kind of message and maybe only create the traversal project file when there is something to add to it?

[leonardochaia]

I'm thinking that, when 0 projects are affected by the changes:

1. Commands should exit with a custom status code
2. generate should not create an empty file

We may wanna toggle the entire behavior with an argument; perhaps your next step in the pipeline expect the (empty) file to be there

That being said, being able to exit with a custom code would allow you to detect that and not execute your next steps in the pipeline.
i.e

dotnet affected [...]
if [ $? -eq <some custom code> ]; then
    echo "##vso[task.setvariable variable=NEEDS_TO_BUILD;]0"
    exit 0
fi

You could then use NEEDS_TO_BUILD in a pipline step condition to prevent executing dotnet build/restore/test if there's no need to and save more build time.

[RafaelMalgor]

I am too late to the party, so I left a comment on the commit, though is already merged.