prefer_inlined_adds

The addition of a list item could be inlined.

The addition of multiple list items could be inlined.

The analyzer produces this diagnostic when the methods add and addAll are invoked on a list literal where the elements being added could be included in the list literal.

The following code produces this diagnostic because the add method is being used to add b, when it could have been included directly in the list literal:

List<String> f(String a, String b) {
  return [a]..add(b);
}

The following code produces this diagnostic because the addAll method is being used to add the elements of b, when it could have been included directly in the list literal:

List<String> f(String a, List<String> b) {
  return [a]..addAll(b);
}

If the add method is being used, then make the argument an element of the list and remove the invocation:

List<String> f(String a, String b) {
  return [a, b];
}

If the addAll method is being used, then use the spread operator on the argument to add its elements to the list and remove the invocation:

List<String> f(String a, List<String> b) {
  return [a, ...b];
}