package require tcltest 2.0
    namespace import ::tcltest::*

    test intro-1 {This is as simple as it gets.} {
        expr 3 * 5
    } 15

    test intro-2 {This illustrates how something goes wrong.} {
        expr 3 * 5
    } 16


    test intro-3 {It's very important to validate responses when         things go wrong.} -body {
        expr 3 / 0
    } -returnCodes error -result {divide by zero}


    test intro-4 {Tcltest, especially with 2.0, is quite powerful 
    and flexible.  Part of the reason it can be puzzling on first
    encounter is that there are typically several different styles
    to write any single test.  Two important choices are whether:  
    the specification is written as a list of clause-pairs, or a
    list of list of clause pairs; and how to leverage tcltest's
    result comparison.  Here's an example, due to Don, that
    illustrates possibilities ...} {
         -result 1
         -body {
             # Complicated calculations
         # if [something_wrong] {error xxx}
         # Still other computations, including logic ...
             return 1
         }
    }