Reducing Cyclomatic Complexity in a select-CodePudding

Good day coding godz,

I am trying to clean up some code and was wondering how to reduce the Cylcomatic Complexity on a method I have created. This method is used during an Import of a CSV file. One of the fields in the CSV file is a license type that is a string (ie "BFI Supervised Lender - Website #2 License") I am converting this to a Integer (1,2,3 or 4) that will be saved to the Database to reference the type of industry based on license type.

Below is my method. Would appreciate some tips for a shade tree VB.NET coder...

Private Function CheckIndustryType(LicName)
    Dim VAR_IndType As Integer

    Select Case Text_LicName
        Case "BFI Level I Check Cashing - Branch License"
            VAR_IndType = 3
        Case "BFI Level II Check Cashing - Branch Certificate"
            VAR_IndType = 3
        Case "BFI Supervised Lender - Branch License"
            VAR_IndType = 1
        Case "BFI Deferred Presentment - Branch License"
            VAR_IndType = 3
        Case "BFI Supervised Lender - Website #1 License"
            VAR_IndType = 1
        Case "BFI Supervised Lender - Website #2 License"
            VAR_IndType = 1
        Case "BFI Supervised Lender - Website #3 License"
            VAR_IndType = 1
        Case "BFI Supervised Lender - Website #4 License"
            VAR_IndType = 1
        Case "BFI Supervised Lender - Website #5 License"
            VAR_IndType = 1
        Case "BFI Supervised Lender - Website #6 License"
            VAR_IndType = 1
        Case "BFI Level II Check Cashing - Company License"
            VAR_IndType = 3
        Case "BFI Level I Check Cashing - Company License"
            VAR_IndType = 3
        Case "fI Branch Mortgage Lender/Servicer"
            VAR_IndType = 2
        Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #1"
            VAR_IndType = 2
        Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #2"
            VAR_IndType = 2
        Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #3"
            VAR_IndType = 2
        Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #4"
            VAR_IndType = 2
        Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #5"
            VAR_IndType = 2
        Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #6"
            VAR_IndType = 2
        Case "BFI Mortgage Lender / Servicer License"
            VAR_IndType = 2
        Case "BFI Mortgage Lender/Servicer License - Other Trade Name #1"
            VAR_IndType = 2
        Case "BFI Mortgage Lender/Servicer License - Other Trade Name #2"
            VAR_IndType = 2
        Case "BFI Mortgage Lender/Servicer License - Other Trade Name #3"
            VAR_IndType = 2
        Case "BFI Mortgage Lender/Servicer License - Other Trade Name #4"
            VAR_IndType = 2
        Case "BFI Mortgage Lender/Servicer License - Other Trade Name #5"
            VAR_IndType = 2
        Case "BFI Mortgage Lender/Servicer License - Other Trade Name #6"
            VAR_IndType = 2
        Case Else
            VAR_IndType = 4
    End Select

    Return VAR_IndType 
End Function

CodePudding user response：

I would use a dictionary in a situation like this. It reduces the number of independent paths to 2, the second is necessary since you're using a default value of course.

Module Module1
    Dim industryTypeMap As New Dictionary(Of String, Int32) From {{"BFI Level I Check Cashing - Branch License", 3},
                                                                           {"BFI Level II Check Cashing - Branch Certificate", 3},
                                                                           {"BFI Supervised Lender - Branch License", 1}}

    Sub Main()
        Console.WriteLine(CheckIndustryType("BFI Supervised Lender - Branch License"))
        Console.WriteLine(CheckIndustryType("BFI Level II Check Cashing - Branch Certificate"))
        Console.WriteLine(CheckIndustryType("Other"))
    End Sub

    Private Function CheckIndustryType(LicName As String)
        Dim industryInt As Int32
        If industryTypeMap.TryGetValue(LicName, industryInt) Then
            Return industryInt
        Else
            Return 4
        End If
    End Function
End Module

This outputs:

1
3
4

You could define the dictionary in the function to maintain all of the code together but that would obviously run slower if you're calling the function repeatedly.

CodePudding user response：

I shortened the number of cases by using StartsWith and Contains with Select Case True.

Private Function CheckIndustryType(LicName As String) As Integer
    Dim VAR_IndType As Integer

    Select Case True
        Case LicName.Contains("Check Cashing")
            VAR_IndType = 3
        Case LicName.StartsWith("BFI Supervised Lender")
            VAR_IndType = 1
        Case LicName.StartsWith("BFI Deferred Presentment")
            VAR_IndType = 3
        Case LicName.StartsWith("fI")
            VAR_IndType = 2
        Case LicName.StartsWith("BFI Branch Mortgage Lender")
            VAR_IndType = 2
        Case Else
            VAR_IndType = 4
    End Select

    Return VAR_IndType
End Function

CodePudding user response：

A long list of long strings is risky, because any change is quite likely to introduce a typo and then the strings don't match. I would probably make an Enum:

Enum LicenseType
  BFILevelICheckCashingBranchLicense
  BFILevelIICheckCashingBranchCertificate
  BFISupervisedLenderBranchLicense
  ...
End Enum

and then test against that value. To reduce the complexity, I would make an attribute like:

Class VarIndTypeAttribute 
  Inherits System.Attribute

    Public VarIndType As Integer
    Sub New(varIndType As Integer
        Me.VarIndType = varIndType
    End Sub

End Class

and then the enum becomes:

Enum
  <VarIndType(3)>
  BFILevelICheckCashingBranchLicense
  <VarIndType(3)>
  BFILevelIICheckCashingBranchCertificate
  <VarIndType(1)>
  BFISupervisedLenderBranchLicense
  ...
End Enum

and then you make a method like

    <Extension>
    Function ToVarIndType(enumValue As [Enum]) As Integer
        Dim att = enumValue.GetAttributeOfType(Of VarIndTypeAttribute)()
        Return If(att IsNot Nothing, att.VarIndType, 0)
    End Function

and then

    Dim valueEnum As LicenseType = ...
    Dim VarIndType = valueEnum.ToVarIndType

and you don't need the lookup function at all!

You probably want VarIndType to be an Enum as well, so you don't have magic values like 0 and 3 throughout the app.