Techniques for Testing Dynamic

1
Techniques for Testing - Dynamic

• Dynamic Testing Techniques
• Black Box Testing
• also called functional testing, or behavioural
  testing
• focuses on the functional requirements of the
  software
• enables the software engineer to derive sets of
  input conditions that will fully exercise all
  functional requirements for a program (test cases
  derived from specifications)
• tends to be applied during later stages of
  testing
• purposely disregards control structure, attention
  is focused on the information domain
• exhaustive functional testing is normally not
  feasible
• use characteristics of input domain to find the
  minimum set of test cases to reveal most defects
• we will study
• Equivalence Partitioning
• Boundary value analysis

2
Techniques for Testing - Dynamic

• Dynamic Testing Techniques
• White Box Testing
• also called glass box testing, or structural
  testing
• uses the control structure of the procedural
  design to derive test cases
• exhaustive structural testing is normally not
  feasible
• to find the minimum set of test cases to exercise
  most important logical paths
• We will study
• Basis Path Testing
• Loop Testing
• Testing Coverage

3
Techniques for Testing - Dynamic

• Equivalence Partitioning
• a black box /functional testing technique
• in determining a set of test cases, this
  technique is to partition the program domain into
  a (small) number of equivalent classes
• the assumption is that if a representative
  element from a class is tested and passed, all
  other elements in the class need not to be tested
  assuming they would pass the test
• How to define equivalent classes
• if a input condition specifies a range, one valid
  and two invalid equivalent classes are defined
• if an input condition requires a specific value,
  one valid and two invalid equivalent classes are
  defined
• if an input condition specifies a member of a
  set, one valid and one invalid equivalent classes
  are defined
• if an input condition is Boolean, one valid and
  one invalid class are defined

4
Techniques for Testing - Dynamic

• Equivalence Partitioning
• Example 1 Online banking
• The user can access the bank using his personal
  computer, providing a 6-digit password, and
  follow with a series of typed commands that
  trigger various banking functions. The software
  supplied for baking application accepts data in
  the form
• area code blank or three digit number not
  beginning with 0 or 1
• password six digit alphanumeric string
• commands check, deposit, or bill pay
• Equivalent classes can be identified for each
  field
• area code(boolean, range, specific value)
• ec1 blank ec2 3-digit numbers (lt200) ec3
  3-digit numbers (200-999) ec4 less than 3-digit
  numbers ec5 more than 3-digit numbers (at least
  one value is needed for test case design)

5
Techniques for Testing - Dynamic

• Equivalence Partitioning
• password (boolean, specific value, set)
• ec6 blank ec7 6-digit alphanumeric
  strings(valid passwords) ec8 6-digit
  alphanumeric strings(invalid passwords) ec9
  less than 6-digit alphanumeric strings ec10
  more than 6-digit alphanumeric strings
• commands(boolean, set)
• ec10 blank ec11 valid (check, deposit,
  bill pay) ec12 invalid
• Example 2 an input condition each book has a
  6-digit number (specific value) can be
  classified as either valid or invalid equivalent
  classes
• one valid class 6-digit numbers
• two invalid classes more or less than 6 digits
• test cases can be constructed to cover the three
  equivalent classes
• Weak point partitioning may be inadequate so
  that the assumption may not hold

6
Techniques for Testing - Dynamic

• Boundary Value Analysis (BVA)
• complements the equivalent class partitioning
  technique
• Assumes software usually fails at boundaries.
• concentrate on the extreme (boundary) values from
  each class (rather than random values from each
  class)
• BVA leads to a selection of test cases that
  exercise bounding values
• output can also be partitioned into equivalent
  classes, and extreme values from each class are
  tested as well
• Guidelines for BVA
• if an input condition specifies a range bounded
  by value a and b, test cases should be designed
  with values a and b, just above and just below a
  and b, respectively (a, b, --a, a, --b, b)
• if an input condition specifies a number of
  values, test cases should be developed that
  exercise the minimum and maximum numbers. Values
  just above and below minimum and maximum are also
  tested

7
Techniques for Testing - Dynamic

• Boundary Value Analysis (BVA)
• Apply guidelines 1 and 2 to output conditions.
  For example, assume that a temperature vs.
  pressure table is required as output from an
  engineering analysis program. Test cases should
  be designed to create an output report that
  produces the maximum (and minimum) allowable
  number of table entries.
• If internal program data structures have
  prescribed boundaries (e.g., an array has a
  defined limit of 100 entries), be certain to
  design a test case to exercise that data
  structure at its boundary.