UnusedOptional

Severity: Low | Category: Optimization

A detector variables and fields with unused optional modifier.

Why is it bad?

Optional is a nullable value that has a special null value indicating the absence of a value. If a developer creates an optional variable or field, he should leverage its functionality by accessing the null value somewhere in his code. Otherwise, the optional type should be removed to simplify and optimize the code.

Example

contract Test {
  a: Int?; // Bad: null value is never accessed
  init() { self.a = 42; }
  get fun getA(): Int { return self.a!!; }
}

Use instead:

contract Test {
  a: Int = 42; // OK: Removed optional
  get fun getA(): Int { return self.a; }
}