Useless call on collection type
Reports filter… calls from the standard library on already filtered collections.
Several functions from the standard library such as filterNotNull() or filterIsInstance have sense only when they are called on receivers that have types distinct from the resulting one. Otherwise, such calls can be omitted as the result will be the same.
Remove redundant call quick-fix can be used to amend the code automatically.
Example:
fun test(list: List<String>) {
val x = list.filterNotNull() // quick-fix simplifies to 'list'
val y = list.filterIsInstance<String>() // quick-fix simplifies to 'list'
}
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.
UselessCallOnCollection- 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.
Availability
- By default bundled with
- Can be installed with plugin
Kotlin, 241.18072-IJ
Last modified: 18 June 2024