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Code Analyzer for VB.NET

There is a newer version: 10.5.0.109200

Why is this an issue?
When Select Case statements
have large sets of multi-line Case clauses, the code becomes hard to read and maintain.
For example, the Cognitive Complexity is going to be particularly high.
In such scenarios, it’s better to refactor the Select Case to only have single-line case clauses.
When all the Case clauses of a Select Case statement are single-line, the readability of the code is not affected.
Exceptions
This rule ignores:

   Select Case statements over Enum arguments 
   fall-through cases 
   Return and Throw statements in Case clauses 

How to fix it
Extract the logic of multi-line Case clauses into separate methods.
Code examples
The examples below use the "Maximum number of case" property set to 4.
Noncompliant code example
Public Function MapChar(ch As Char, value As Integer) As Integer ' Noncompliant
    Select Case ch
        Case "a"c
            Return 1
        Case "b"c
            Return 2
        Case "c"c
            Return 3
        ' ...
        Case "-"c
            If value > 10 Then
                Return 42
            ElseIf value < 5 AndAlso value > 1 Then
                Return 21
            End If
            Return 99
        Case Else
            Return 1000
    End Select
End Function

Compliant solution
Public Function MapChar(ch As Char, value As Integer) As Integer
    Select Case ch
        Case "a"c
            Return 1
        Case "b"c
            Return 2
        Case "c"c
            Return 3
        ' ...
        Case "-"c
            Return HandleDash(value)
        Case Else
            Return 1000
    End Select
End Function

Private Function HandleDash(value As Integer) As Integer
    If value > 10 Then
        Return 42
    ElseIf value < 5 AndAlso value > 1 Then
        Return 21
    End If
    Return 99
End Function

Resources
Documentation

   Sonar - Cognitive Complexity 
   Microsoft Learn - Select…Case Statement