Call of Java mutator method on immutable Kotlin collection

Reports Java mutator methods calls (like fill, reverse, shuffle, sort) on an immutable Kotlin collection.

This can lead to UnsupportedOperationException at runtime.

Example:

  import java.util.Collections

  fun test() {
      val immutableList = listOf(1, 2)
      Collections.reverse(immutableList)
  }

To fix the problem make the list mutable.

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

JavaCollectionsStaticMethodOnImmutableList

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Kotlin | Java interop issues

Inspection Details
By default bundled with:	IntelliJ IDEA 2024.2, Qodana for JVM 2024.2,
Can be installed with plugin:	Kotlin, 242.22892-IJ

Last modified: 11 September 2024