NullCheckOnMutableProperty.md

Pattern: Use of null-check on mutable property

Issue: -

Description

Reports null-checks on mutable properties, as these properties' value can be changed and thus make the null-check invalid after the execution of the if-statement.

Example of incorrect code:

class A(private var a: Int?) {
  fun foo() {
    if (a != null) {
      println(2 + a!!)
    }
  }
}

Example of correct code:

class A(private val a: Int?) {
  fun foo() {
    if (a != null) {
      println(2 + a)
    }
  }
}

Further Reading

• Detekt - NullCheckOnMutableProperty