Rule137DoNotDeclareVariablesThatAreUnused ArgumentNullException with empty options

[MODUSCarstenScholling]

Describe the bug A combination of an Option parameter with empty string and local variable declaration causing an ArgumentNullException in CodeCop.

To Reproduce

procedure AnalyzerException(someOptions: Option FirstOption,,LastOption): Boolean
var
    removeMeToRemoveExceptions: Boolean;
begin
    exit(removeMeToRemoveExceptions);
end;

The above procedure causes the following exception: Analyzer 'Microsoft.Dynamics.Nav.CodeCop.Design.Rule137DoNotDeclareVariablesThatAreUnused' threw an exception of type 'System.ArgumentNullException' with message 'System.ArgumentNullException: Value cannot be null.

If you either remove the local variable OR give a proper name to the empty option, the exception disappears.

Exception

procedure AnalyzerException(someOptions: Option FirstOption,,LastOption): Boolean
var
    removeMeToRemoveExceptions: Boolean;
begin
    exit(removeMeToRemoveExceptions);
end;

NO Exception

procedure AnalyzerException(someOptions: Option FirstOption,SecondOption,LastOption): Boolean
var
    removeMeToRemoveExceptions: Boolean;
begin
    exit(removeMeToRemoveExceptions);
end;

NO Exception

procedure AnalyzerException(someOptions: Option FirstOption,,LastOption): Boolean
begin
    exit(removeMeToRemoveExceptions);
end;

Expected behavior No exception in first example procedure.

Versions:

• AL Language: Name: AL Language Id: ms-dynamics-smb.al Description: AL development tools for Dynamics 365 Business Central Version: 3.0.126610 Publisher: Microsoft VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=ms-dynamics-smb.al

Example app: AnalyzerException.zip

[tinfister]

Try to use someOptions: Option FirstOption,"",LastOption;

This warning was weird to us to because it didn't highlight the option with wrong options, instead reported problem in app.json file.

[MODUSCarstenScholling]

Well, it's not the option or the option values that are the problem, but rather the fact that something like that, which is valid code, must not lead to an exception without getting information about the code position. Fixing is our smallest problem.

[MarcHansenMicrosoft]

Fixed

[MODUSCarstenScholling]

Thank you!