DataClassShouldBeImmutable.md

Pattern: Mutable property in data class

Issue: -

Description

Data classes should mainly be used to store immutable data. This rule assumes that they should not contain any mutable properties.

Example of incorrect code:

data class MutableDataClass(var i: Int) {
    var s: String? = null
}

Example of correct code:

data class ImmutableDataClass(
    val i: Int,
    val s: String?
)

Further Reading

• Detekt - DataClassShouldBeImmutable