Regression in 2.41.0, no longer ignoring target/generated-sources

[hylkevds]

Version 2.40.0 works without problems, switching to 2.41.0 fails the build due to formatting violations in code in target/generated-sources. Naturally, source code in target should not be checked for formatting violations.
The Changelog mentions #1846 that is probably related, but I'm not sure what config option to use to fix the issue.

• Apache Maven 3.8.6
• Linux Mint
• Repository: https://github.com/FraunhoferIOSB/FROST-Server
  Spotless version is line 139 of the pom.xml
• Failed build: https://github.com/FraunhoferIOSB/FROST-Server/actions/runs/7001504245/job/19043692393?pr=1826

If you are submitting a bug, please include the following:

• summary of problem
• Gradle or Maven version
• spotless version
• operating system and version
• copy-paste your full Spotless configuration block(s), and a link to a public git repo that reproduces the problem if possible
• copy-paste the full content of any console errors emitted by gradlew spotless[Apply/Check] --stacktrace

[hylkevds]

Found the fix:

                            <excludes>
                                <exclude>target/**</exclude>
                            </excludes>

in the <java> configuration block.
If excluding target by default is not feasible, then it may a good idea to add that to the examples.

[julius-d]

I tried to update my project to spotless-maven-plugin version 2.41.0 but it fails with:

Failed to execute goal com.diffplug.spotless:spotless-maven-plugin:2.41.0:check (default) on project my-service: 
The following files had format violations:
     target/generated-sources/openapi/src/main/java [...]

I think that the generated-sources should not be checked by default!

[basil]

Same issue in the Jenkins project — all our builds are now failing due to this regression.

I think that the generated-sources should not be checked by default!

Agreed.

[nedtwigg]

For anybody who has this problem, can you please

• 👍 if adding <exclude>target/**</exclude> would have made this seamless for you
• 👎 if you still would have a problem, and so you wish that we reverted feat: Maven plugin uses CompileSourceRoots #1847 altogether

[jlorenzen]

Ran into this issue on all my team's projects. I think I would prefer maintaining backwards compatible behavior.
If one wants to run spotless on generated code, they should change the output directory to src/main/java so they can check the code in. Not sure why you'd want to run spotless on generated code that is not checked in.

[lutovich]

So sorry about this issue! Here's a revert PR: #1928. It does feel correct to restore the previous behavior.

[tisonkun]

For an even better solution, I ever think of respecting gitignore configs.

I implement a similar function in apache/skywalking-eyes#13.

And plan to implement in a Java codebase https://github.com/korandoru/hawkeye/blob/main/hawkeye-core/src/main/java/io/korandoru/hawkeye/core/Selection.java with JGit.

For your reference :D

[nedtwigg]

We went with a full revert to the previous behavior in plugin-maven 2.41.1. If it comes back, it'll be flag-gated and possibly also enhanced with .gitignore, tbd.