anchor.diff:  
       // Pattern Matching
       | BasicPatterns.DecisionTree(decisionExpr, decisionTargets) ->
  -        let! fableDecisionExpr = transformExpr com ctx decisionExpr 
  +        let! fableDecisionExpr = transformExpr com ctx decisionExpr
           let rec transformDecisionTargets acc xs =
               trampoline {
                   match xs with
  
positive.code:                 | BasicPatterns.IfThenElse(BasicPatterns.UnionCaseTest(unionValue, unionType, unionCaseInfo), _, _) ->
                      let rangeOfLastDecisionTarget = makeRangeFrom (snd (List.last decisionTargets))
                      let errorMessage = 
                          sprintf "The match cases were incomplete: case '%s' of type '%s' was not handled at %s" 
                              unionCaseInfo.Name 
                              unionType.TypeDefinition.DisplayName
                              fileNameWhereErrorOccurs
                      let errorExpr = createThrowErrorExpr errorMessage rangeOfLastDecisionTarget 
  
                      fableDecisionTargets
                      |> List.replaceLast (fun lastExpr -> [], errorExpr)
                  | _ ->
                      fableDecisionTargets
              | None -> fableDecisionTargets
  
          return Fable.DecisionTree(fableDecisionExpr, compiledFableTargets)
  
negative.code: 
          let! fableDecisionTargets = transformDecisionTargets [] decisionTargets
          
          // rewrite last decision target if it throws MatchFailureException
          let compiledFableTargets = 
              match isRasingMatchFailureExpr (snd (List.last decisionTargets)) with 
              | Some fileNameWhereErrorOccurs -> 
  