“Refactoring is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior. Its heart is a series of small behavior preserving transformations. Each transformation (called a ‘refactoring’) does little, but a sequence of transformations can produce a significant restructuring. Since each refactoring is small, it’s less likely to go wrong. The system is also kept fully working after each small refactoring, reducing the chances that a system can get seriously broken during the restructuring. “

Martin Fowler

Test Automation / VBScript / Refactoring

Subject: Code Block

Heuristic: Floating Point Comparison

Before

ArgA = ValueA1/ValueA2
ArgB = ValueB1/ValueB2
If ArgA = ArgB Then
'
End If

Check business requirements and system requirements. Is $0.0001 equal to $0.00009 ?

After

'Define range based on business or system requirements
DeltaRange = 0.00001
'
ArgA = ValueA1/ValueA2
ArgB = ValueB1/ValueB2
If Abs(ArgA-ArgB) < DeltaRange Then
'
End If

Heuristic: String Comparison

Before

If StrA = StrB Then
'
End If

Is your comparison case-sensitive or not? Do you want to exclude heading and trailing space characters?

After

strA = UCase(Trim(strA))
strB = UCase(Trim(strB))
If StrA = StrB Then
'
End If

Heuristic: String Operations

Before

If UCase(strUsername) = "ADMIN" Then
'
End If
If UCase(strUsername) = "CONTRIBUTOR" Then
'
End If
If UCase(strUsername) = "VISITOR" Then
'
End If

String operations are performance-costly. Avoid / clean up unnecessary calls.

After

strUsername = UCase(strUsername)
If strUsername = "ADMIN" Then
'
End If
If strUsername = "CONTRIBUTOR" Then
'
End If
If strUsername = "VISITOR" Then
'
End If

Subject: Object Class

Heuristic: Constructor

Before

Class MyClass
  Public MyProperty
End Class
'
Public Function InitMyClass()
  Dim objMyClass
  Set objMyClass = new MyClass
  objMyClass.MyProperty = TRUE
  Set InitMyClass = objMyClass
End Function

Encapsulate default initialization within class constructor which is called automatically.

After

Class MyClass
  Public MyProperty
  '
  Private Sub Class_Initialize()
    MyProperty = TRUE
  End Sub
End Class
'
Public Function InitMyClass()
  Set InitMyClass = new MyClass
End Function

Heuristic: Destructor

Before

Class MyClass
  Public objMyProperty
  '
  '
End Class
'

Define destructors to explicitly release objects used as class properties.

After

Class MyClass
  Public objMyProperty
  '
  Private Sub Class_Terminate()
    Set objMyProperty= Nothing
  End Sub
End Class
'