Why is this an issue?
Most developers expect property access to be as efficient as field access. However, if a property returns a copy of an array or collection, it will
be much slower than simple field access, contrary to the caller’s likely expectations. Therefore, such properties should be refactored into methods so
that callers are not surprised by the unexpectedly poor performance.
This rule detects calls to ToList, ToArray and array Clone.
Noncompliant code example
private List<string> _foo = new List<string> { "a", "b", "c" };
public IEnumerable<string> Foo // Noncompliant
{
get
{
return _foo.ToList();
}
}
private string[] _bar = new string[] { "a", "b", "c" };
public IEnumerable<string> Bar // Noncompliant
{
get
{
return (string[])_bar.Clone();
}
}
Compliant solution
private List<string> _foo = new List<string> { "a", "b", "c" };
private string[] _bar = new string[] { "a", "b", "c" };
public IEnumerable<string> GetFoo()
{
return _foo.ToList();
}
public IEnumerable<string> GetBar()
{
return (string[])_bar.Clone();
}
