Refactor

// BAD: Private leaks into every called function
- User Function ProcessOrder()
-   Private cOrder := ""
-   Private nTotal := 0
-   Private lOk    := .T.
-   // ... business logic ...
- Return

// GOOD: Local variables stay in scope
+ User Function ProcessOrder()
+   Local cOrder := "" as Character
+   Local nTotal := 0  as Numeric
+   Local lOk    := .T. as Logical
+   // ... business logic ...
+ Return

// BAD: Monolithic Function (300+ lines)
- User Function FINA010()
-   // 60 lines: header validation
-   // 80 lines: item processing
-   // 50 lines: tax calculation
-   // 40 lines: ledger posting
-   // 70 lines: notification
- Return

// GOOD: Decomposed into focused Static Functions
+ User Function FINA010()
+   Local lOk as Logical
+   lOk := ValidateHeader()
+   If lOk
+     lOk := ProcessItems()
+   EndIf
+   If lOk
+     lOk := CalculateTaxes()
+   EndIf
+   If lOk
+     lOk := PostToLedger()
+   EndIf
+   If lOk
+     SendNotifications()
+   EndIf
+ Return
+
+ Static Function ValidateHeader() as Logical
+   // focused header validation
+ Return lRet
+
+ Static Function ProcessItems() as Logical
+   // focused item processing
+ Return lRet

// BAD: Untyped parameters and return (AdvPL legacy style)
- Static Function CalcTotal(cClient, aItems)
-   Local nTotal := 0
-   // ...
- Return nTotal

// GOOD: Fully typed (TLPP)
+ Static Function CalcTotal(cClient as Character, aItems as Array) as Numeric
+   Local nTotal := 0 as Numeric
+   Local nI     := 0 as Numeric
+   For nI := 1 To Len(aItems)
+     nTotal += aItems[nI][2] * aItems[nI][3]  // qty * price
+   Next nI
+ Return nTotal

// BAD: AdvPL error handling with ErrorBlock
- Local bError := ErrorBlock({|e| DefError(e)})
- BEGIN SEQUENCE
-   // risky operation
- END SEQUENCE
- ErrorBlock(bError)

// GOOD: TLPP Try-Catch
+ Try
+   // risky operation
+ Catch oError
+   FWLogMsg("ERROR", , "APP", "MyFunction", , "01", oError:Description, 0, 0, {})
+   // handle or re-throw
+ EndTry

// BAD: Macro-execution for dynamic field access
- cField := "SA1->A1_NOME"
- xValue := &(cField)

// GOOD: FieldGet / indirect access
+ cAlias := "SA1"
+ cField := "A1_NOME"
+ xValue := (cAlias)->(FieldGet(FieldPos(cField)))

// BAD: AdvPL StaticCall (not allowed in TLPP)
- xResult := StaticCall(TMyClass, MyMethod, cParam)

// GOOD: TLPP direct static method call
+ xResult := TMyClass():MyMethod(cParam)

// BAD: Missing DbSelectArea and RecLock
- DbSetOrder(1)
- DbSeek(cKey)
- SA1->A1_NOME := cNewName
- MsUnlock()

// GOOD: Proper workarea selection and locking
+ DbSelectArea("SA1")
+ DbSetOrder(1)
+ If DbSeek(cKey)
+   If RecLock("SA1", .F.)
+     SA1->A1_NOME := cNewName
+     MsUnlock()
+   EndIf
+ EndIf

// BAD: Legacy obsolete includes
- #include "protheus.ch"
- #include "Ap5Mail.ch"
- #include "ApWizard.ch"
- #include "FileIO.ch"
- #include "Font.ch"
- #include "ParmType.ch"
- #include "RWMake.ch"

// GOOD: Single modern include
+ #include "totvs.ch"

// BAD: TLPP source without namespace (global scope pollution)
- #include "tlpp-core.th"
- Static Function Helper()
-   // ...
- Return

// GOOD: Namespaced TLPP source
+ #include "tlpp-core.th"
+ Namespace finance.receivable
+
+ Static Function Helper() as Logical
+   // ...
+ Return .T.