Gendarme.Rules.Correctness.CheckParametersNullityInVisibleMethodsRule(git)

CheckParametersNullityInVisibleMethodsRule

Assembly: Gendarme.Rules.Correctness
Version: git

Description

This rule checks if all nullable parameters of visible methods are compared with '''null''' before they get used. This reduce the likelyhood of the runtime throwing a NullReferenceException.

Examples

Bad example:

[DllImport ("message")]
internal static extern byte [] Parse (string s, int length);
public bool TryParse (string s, out Message m)
{
    // is 's' is null then 's.Length' will throw a NullReferenceException
    // which a TryParse method should never do
    byte [] data = Parse (s, s.Length);
    if (data == null) {
        m = null;
        return false;
    }
    m = new Message (data);
    return true;
}

Good example:

[DllImport ("message")]
internal static extern byte [] Parse (string s, int length);
public bool TryParse (string s, out Message m)
{
    if (s == null) {
        m = null;
        return false;
    }
    byte [] data = Parse (s, s.Length);
    if (data == null) {
        m = null;
        return false;
    }
    m = new Message (data);
    return true;
}

Notes

• This rule is available since Gendarme 2.2

Source code

You can browse the latest source code of this rule on github.com