Hi :wave: . I am trying to write to a custom rule...

# detekt

[Rajat Varyani]

Hi 👋 . I am trying to write to a custom rule to detect mutation in code. This involves checking for presence of Mutable collections, keywords like var in codebase. What is i could come up till now is

override fun visitDeclaration(dcl: KtDeclaration) {
        super.visitDeclaration(dcl)
        if (dcl is KtProperty && dcl.isVar) {
            report(CodeSmell(issue, Entity.from(dcl), "Mutation in code"))
        }
    }

Now I am writing code to detect keywords like

val list = mutableListOf(1, 2)

. I am not sure how to go about it?

[Brais Gabin]

For things like mutableListOf() you could take this rule as example: https://github.com/arturbosch/detekt/blob/master/detekt-rules/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/ForbiddenMethodCall.kt

[Brais Gabin]

Detekt doesn’t have a `ForbiddenClass`… I suppose that usually all the classes are used with an import stament so it’s easier to forbid the import… But ForbiddenImport doesn’t help you…

[Brais Gabin]

Maybe you can check the code in ExplicitCollectionElementAccessMethod. It looks for uses of Map so probably you can take some ideas from it.

[Rajat Varyani]

Thanks. Let me try that.