Reports calls to associate() and associateTo() that can be replaced with associateBy() or associateWith().

Both functions accept a transformer function applied to elements of a given sequence or collection (as a receiver). The pairs are then used to build the resulting Map.

Given the transformer refers to it, the associate[To]() call can be replaced with more performant associateBy() or associateWith().

Examples:

  fun getKey(i: Int) = 1L
  fun getValue(i: Int) = 1L

  fun test() {
      arrayOf(1).associate { getKey(it) to it }  // replaceable 'associate()'
      listOf(1).associate { it to getValue(it) } // replaceable 'associate()'
  }

After the quick-fix is applied:

  fun getKey(i: Int) = 1L
  fun getValue(i: Int) = 1L

  fun test() {
      arrayOf(1).associateBy { getKey(it) }
      listOf(1).associateWith { getValue(it) }
  }