CS 3302 Summer, 1998
Assignment: 2
Percentage of Final grade: 5 percent.
Due: By email Thursday, July 9th at beginning of class.
This is an individual  assignment.

1. Derive a set of black-box test cases for EACH of the following 
components:

(a) A function that takes a line of text as input and counts 
the number of non-blank characters in the line.

(b) A function that examines a line of text and replaces sequences
of spaces with a single space.

Each test case in your answer should consist of an input, the expected
output for that input, and a phrase describing the equivalence class 
or boundary value that the test case represents. You may assume that 
the functions are written in a strongly-typed language and that their 
inputs are guaranteed to be strings of characters. For invalid input
strings, make assumptions about what the function should do in those 
cases and base your test cases on those assumptions.

2. Suppose that the functions above are among a larger number of 
editing functions provided by a TextLine abstract data type that is 
about 1 KLOC (thousand lines of code) long. Two testers, A and B, 
working independently design and apply their test cases to the 
TextLine ADT.  Tester A finds 10 faults in the ADT, and tester B 
finds 12. Seven of the identified faults are common to Tester A and B.

(a) What is your best estimate of the number of faults remaining in 
the ADT? Explain any simplifying assumptions that you make to arrive 
at your estimate.

(b) Would you be satisfied to release the code in its current state? 
Justify your answer. If you would not release the code yet, when 
would you?

(c) Under what circumstances do you think it would be good professional 
practice to use metrics derived from the above data (e.g. defects per 
KLOC written or defects detected per person-day of testing) to assess 
the job performance of individual programmers and testers or of 
programming and testing teams?

(d) Explain in no more than one paragraph what you would do if your 
project manager insisted that the ADT be included in the current 
software release once the known defects had been corrected. (You may 
assume that correcting the known defects did not result in any new 
ones.)