FROM THE TESTING TRENCHES COMMON LOGIC LAPSES AND HOW TO AVOID THEM

FROM THE TESTING TRENCHESCOMMON LOGIC LAPSES AND HOW TO AVOID THEM

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WHAT IS A LOGIC LAPSE?

• Code runs without error• Output looks reasonable• Log files look reasonable• Off to QA for testing and …


KA-BOOM!


LOGIC LAPSES

• Applying a DATETIME format to a SAS date


WHAT IT LOOKS LIKE…


HOW TO FIX…

• Apply date format to date variableselect IssueDate format=DATE9. as Issue_Date

• Create DATETIME variable and apply DATETIME formatselect dhms(IssueDate,0,0,0) format=DATETIME23. as Issue_DTTM


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats




HOW TO FIX…


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly




HOW TO FIX…


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity



9 proc sql;10 create table Case_Example_1 as11 select City,County,State,ZIP12 from Case_Example13 where city="RALEIGH";NOTE: Table WORK.CASE_EXAMPLE_1 created, with 0 rows and 4 columns.

13 ! quit;


HOW TO FIX…

15 proc sql;16 create table Case_Example_2 as17 select City,County,State,ZIP18 from Case_Example19 where upcase(city)="RALEIGH";NOTE: Table WORK.CASE_EXAMPLE_2 created, with 44 rows and 4 columns.

19 ! quit;


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity• Not accounting for leading or trailing blanks



15 proc sql;16 create table Example_1 as17 select distinct a.ncgeneralstatute || ' - ' ||b.ncgeneralstatutedescription as NCGS_CAT18 from extract.sor_offense as a19 left join extract.sor_refncstatute as b20 on a.ncgeneralstatute=b.ncgeneralstatute21 ;


HOW TO FIX…

23 proc sql;24 create table Example_2 as25 select distinct catx(' - ', a.ncgeneralstatute,b.ncgeneralstatutedescription) as NCGS_CATX26 from extract.sor_offense as a27 left join extract.sor_refncstatute as b28 on a.ncgeneralstatute=b.ncgeneralstatute29 ;


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity• Not accounting for leading or trailing blanks• Not accounting for hex characters



31 proc sql;32 create table Hex_Example_1 as33 select *34 from Hex_Example35 where upcase(city)="RALEIGH";NOTE: Table WORK.HEX_EXAMPLE_1 created, with 0 rows and 5 columns.

35 ! quit;


HOW TO FIX…

37 proc sql;38 create table Hex_Example_2 as39 select *40 from Hex_Example41 where upcase(compress(city,,'ak'))="RALEIGH";NOTE: Table WORK.HEX_EXAMPLE_2 created, with 44 rows and 5 columns.

41 ! quit;


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity• Not accounting for leading or trailing blanks• Not accounting for hex characters• Incorrect handling of endpoints



• Greater than versus Greater than or equal to• Less than versus Less than or equal to• Less than versus Greater than• LE versus GE• Displaying age


HOW TO FIX…

• Query test data for cases• where date falls inside or outside test range• where date matches endpoints• where birthday matches test date• where date is missing


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity• Not accounting for leading or trailing blanks• Not accounting for hex characters• Incorrect handling of endpoints• Incorrect sorting (primary/secondary/tertiary)




LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity• Not accounting for leading or trailing blanks• Not accounting for hex characters• Incorrect handling of endpoints• Incorrect sorting (primary/secondary/tertiary)• Losing data when converting text strings to SAS dates



• All digits, but invalid date (leap day in non-leap years)• 19870229

• Missing digits and/or spaces• 194 0116

• Unexpected characters • 20??0704• 0101 &A

• Nonexistent dates• 19821169


HOW TO FIX…


LOGIC LAPSES

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity• Not accounting for leading or trailing blanks• Not accounting for hex characters• Incorrect handling of endpoints• Incorrect sorting (primary/secondary/tertiary)• Losing data when converting text strings to SAS dates• Not imposing integrity constraints on input parameters





year pred succ 2023 A B

pos account year excess fy_1 fy_2 fy_3succ B 2020 $0.00 $0 $0 $0 succ B 2021 $0.00 $0 $0 $0 succ B 2022 $0.00 $0 $0 $0 succ B 2023 $0.00 $0 $0 $0 pred A 2020 $0.00 $0 $0 $0 pred A 2021 $0.00 $0 $0 $0 pred A 2022 $0.00 $0 $0 $0 pred A 2023 $0.00 $0 $0 $0


HOW TO FIX…


LOGIC LAPSE SUMMARY

• Applying a DATETIME format to a SAS date• Not checking for undefined formats• Parsing incorrectly• Not accounting for case sensitivity• Not accounting for leading or trailing blanks• Not accounting for hex characters• Incorrect handling of endpoints• Incorrect sorting (primary/secondary/tertiary)• Losing data when converting text strings to SAS dates• Not imposing integrity constraints on input parameters


ACKNOWLEDGMENTS

Thanks to the developers whose defects

made this presentation possible.

FOR ADDITIONAL INFORMATION, CONTACT:

Jenni M. Elion

Senior Development Tester ▪ SAS Solutions OnDemand

Tel: + 1 919 531 2642 ▪ [email protected]

100 SAS Campus Drive ▪ Cary, NC 27513-2414 USA

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FROM THE TESTING TRENCHES COMMON LOGIC LAPSES AND HOW TO AVOID THEM