Add RemoveDuplicateDependencies recipe for Gradle

What problem are you trying to solve?

For Maven, there is a RemoveDuplicateDependencies recipe to remove duplicate dependencies from a project.

I would like to have the same functionality for Gradle projects.

What precondition(s) should be checked before applying this recipe?

Gradle projects

Describe the situation before applying the recipe

• This new recipe would be useful to solve a bug in the Jackson recipe as described in https://github.com/openrewrite/rewrite-jackson/issues/37.

In that case, when the input is:

implementation "com.fasterxml.jackson.core:jackson-databind"
implementation "com.fasterxml.jackson.module:jackson-module-parameter-names"

the output is:

implementation "tools.jackson.core:jackson-databind"
implementation "tools.jackson.core:jackson-databind"

Describe the situation after applying the recipe

In the case described above, I'd like the output to be:

implementation "tools.jackson.core:jackson-databind"

Have you considered any alternatives or workarounds?

I haven't found alternative strategies except writing a custom recipe.

Are you interested in contributing this recipe to OpenRewrite?

Yes, with some guidance

Start by reading rewrite-maven/src/main/java/org/openrewrite/maven/RemoveDuplicateDependencies.java, the existing Maven analogue. Use the Jackson issue linked in the description and its before/after examples as the behavioral reference; done means a Gradle project with duplicate dependencies produces one remaining dependency.