Add option to disable m2e problem reporting

[Marcono1234]

Version

• OS: Windows 10
• Maven Plugin: 2.43.0
• Eclipse: 2023-12 (4.30.0)

Description

Relates to #1814

It seems the m2e formatting issue reporting (#1962) is enabled by default and cannot be disabled. The way these issues are reported is in my opinion a bit problematic:

• They are reported as errors with a big red icon
• The description of the error can be difficult to read and understand (even to understand that this is related to Spotless), especially for larger sections

Example:

Even if this can be adjusted or improved, e.g. by using a different severity (if possible) and making the message more concise, it might in some cases be useful to completely disable this in the plugin configuration. For example for the use case of letting users write the code in whatever formatting they want (without requiring them to adjust their IDE), and then only requiring running mvn spotless:apply once in the end. For that case, these errors during development might just be distracting and might actually scare away new contributors to the project using Spotless.

Example project

https://github.com/google/gson

Writing code in Eclipse IDE which does not match the Google Code Style shows multiple Maven errors due to formatting violations.

[Marcono1234]

Maybe there is also a bug with the error reporting that these errors just accumulate without ever being cleared, as long as there is still any formatting violation at that line.

[kwin]

Indeed there is an issue with not removing old error markers. I will try to come up with a fix. This is a regression of #1962. In addition allowing to disable m2e execution (and therefore prevent emitting of errors within Eclipse) and allowing to tweak the severity of message markers in incremental builds via another plugin parameter should be possible to support as well.

[Marcono1234]

Thanks a lot for looking into this!

I am not that familiar with Eclipse's internals, m2e and Maven incremental builds, so I have some questions regarding your proposed changes:

• Are there cases where Eclipse / m2e performs a non-incremental build and these error markers could still occur inside Eclipse?
  Please don't get me wrong, these Eclipse error markers can probably be quite useful for projects where all contributors are aware of the build setup and the Spotless usage.
  But for public open source projects where new contributors might not know anything about the build setup (or might have never used Spotless) I think these error or warning markers in Eclipse can be confusing and it would be useful to disable them completely. And instead let users check and fix Spotless violations at the end with mvn spotless:....
• Do your proposed changes affect non-m2e builds as well?
  For example, could it happen that users run mvn ... and Spotless is not executed and would miss formatting violations due to this?

[kwin]

Are there cases where Eclipse / m2e performs a non-incremental build and these error markers could still occur inside Eclipse?

No, they are only emitted for incremental build

Do your proposed changes affect non-m2e builds as well

No!

[Marcono1234]

Do your proposed changes affect non-m2e builds as well

No!

Thanks for the clarification. I just wasn't sure because the condition in AbstractSpotlessMojo.shouldSkip() looked like it is general Maven API and not something m2e / Eclipse-specific.