RedundantHigherOrderMapUsage.md

Pattern: Redundant map usage

Issue: -

Description

Redundant maps add complexity to the code and accomplish nothing. They should be removed or replaced with the proper operator.

Example of incorrect code:

fun foo(list: List<Int>): List<Int> {
    return list
        .filter { it > 5 }
        .map { it }
}

fun bar(list: List<Int>): List<Int> {
    return list
        .filter { it > 5 }
        .map {
            doSomething(it)
            it
        }
}

fun baz(set: Set<Int>): List<Int> {
    return set.map { it }
}

Example of correct code:

fun foo(list: List<Int>): List<Int> {
    return list
        .filter { it > 5 }
}

fun bar(list: List<Int>): List<Int> {
    return list
        .filter { it > 5 }
        .onEach {
            doSomething(it)
        }
}

fun baz(set: Set<Int>): List<Int> {
    return set.toList()
}

Further Reading

• Detekt - RedundantHigherOrderMapUsage