Computer Science 15-110, Fall 2010, Lecture 2
Testing and Debugging

• Testing
• unit testing
• testFoo() for each function foo()
• make your own test cases!  Look for "edge" or "boundary" or just "weird" cases!
• testAll()
• print expected and observed values when assertions fail!
  
  
• Debugging
• read stack trace output on crashes!
• print statements, the debug() function, and the db() function
• assertions and invariants
• disabling events + simulating events
• profiling with time.time() and with cProfile.run("myTest()")
• use the pdb Python debugger
• break into debugger with:    import pdb; pdb.set_trace()
  
• some commands:
• h        help
• l        list source code near the current line
• w        where (print stack trace)
• a        arglist:  print the arglist of the current function
• p expr   print the value of the expression
• pp expr  same as p, only "pretty-printed"
  
• s        step into called functions
• n        next (step over called functions)
• r        return:  run until this function returns
  
• c        continue (run again)
• !stmt    execute the stmt in the current context
  
• q        quit from the debugger