Only add a Gradle wrapper if there is a Gradle project

[shanman190]

What's changed?

Modify UpdateGradleWrapper to only generate a wrapper when it has deduced that there also exists a Gradle project within the source set.

What's your motivation?

When running the recipe with either the default or an explicit true value for the addIfMissing parameter will result in a new Gradle wrapper being generated at the root of the project, even if one doesn't make sense for the repository at hand.

Anything in particular you'd like reviewers to focus on?

Are there use cases where a Gradle wrapper may be desired and a Gradle project doesn't exist? 🤔

Anyone you would like to review specifically?

Anyone

Have you considered any alternatives or workarounds?

• Use a precondition to gate the generation within upstream recipes
• Be more selective when using the default or explicit true value for the addIfMissing parameter

Any additional context

N/A

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[sjungling]

Thank you for this improvement!

[timtebeek]

Great to see, thanks! Now we no longer have to remember not to add the wrapper to rewrite-maven-plugin 😁