Possible false positive with c# list .FirstOrDefault where default value given

Rules and Languages New rules / language support
1

Since .NET 6, Linq added an overload to object.FirstOrDefault(lamda, object default) which allows the developer to offer a default object to read data from in the case that a match was not found for the lamda expression. An example is below:

object DefaultValue = new() {Value = “SomeValue”, Text = “Show Me”};
string MyValue = AllValues.FirstOrDefault(x => x.Value == “MyDesiredValue”, DefaultValue).Text;

In the above case, if no Value exists in the list of AllValues equal to “MyDesiredValue”, the resulting value for the Text property would be “Show Me”. There should never be a null in this case because we provided a non-null default.

SonarQube currently flags above code as a medium bug with the explanation that it could result in a null exception which is not possible. I believe this needs to be added to acceptable logic.

2

Hi,

Welcome to the community and thanks for this report!

Can you give your context for this? I.e. are you on SonarQube Cloud? SonarQube for IDE (flavor and version)? SonarQube self-managed (flavor and version)?

 
Thx,
Ann

3

Sure, sorry should have included this. This is in an analysis done by SonarQube Server in our Azdo Pipeline.

4

Hi,

Tell me about your SonarQube Server version, please. You can find it in the page footer if you’re not sure what it is.

 
Thx,
Ann

5

Enterprise version 2025.6.1 (117629)

1 Like
7

Hi,

Thanks! I’ve flagged this for the language experts.

 
Ann