All Pairs

This is the third and final fixture of a suite that make up the AllPairsExample. Like with AllFiles, we expand wildcard characters in path specifications to get lists of tests. And, like in AllCombinations, we enumerate cases drawing from these lists one test at a time in sequence. But here our goal is only to test all possible pairs of test, which will require fewer cases.

Here is the same specification we used to test the CalculatorExample in AllCombinations. Try it using AllPairs.

http:run.cgi

eg.AllPairs
Documents/AllPairs/magnitude/*.html  
Documents/AllPairs/sign/*.html  
Documents/AllPairs/function/*.html  
#1
180+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
change-sign.html 0 right, 0 wrong, 0 ignored, 1 exceptions [1]
cosine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#2
180+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
multiply.html 0 right, 0 wrong, 0 ignored, 0 exceptions
sine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#3
180+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
no-change.html 0 right, 0 wrong, 0 ignored, 0 exceptions
cosine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#4
30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
change-sign.html 0 right, 0 wrong, 0 ignored, 1 exceptions [2]
cosine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#5
30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
multiply.html 0 right, 0 wrong, 0 ignored, 0 exceptions
sine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#6
30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
no-change.html 0 right, 0 wrong, 0 ignored, 0 exceptions
sine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#7
360+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
change-sign.html 0 right, 0 wrong, 0 ignored, 1 exceptions [3]
cosine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#8
360+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
multiply.html 0 right, 0 wrong, 0 ignored, 0 exceptions
sine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#9
360+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
no-change.html 0 right, 0 wrong, 0 ignored, 0 exceptions
cosine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#10
90-30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
change-sign.html 0 right, 0 wrong, 0 ignored, 1 exceptions [4]
cosine.html 0 right, 1 wrong, 0 ignored, 0 exceptions [5]
#11
90-30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
multiply.html 0 right, 0 wrong, 0 ignored, 0 exceptions
sine.html 0 right, 1 wrong, 0 ignored, 0 exceptions [6]
#12
90-30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
no-change.html 0 right, 0 wrong, 0 ignored, 0 exceptions
cosine.html 0 right, 1 wrong, 0 ignored, 0 exceptions [7]
#13
180+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
change-sign.html 0 right, 0 wrong, 0 ignored, 1 exceptions [8]
cosine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#14
180+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
change-sign.html 0 right, 0 wrong, 0 ignored, 1 exceptions [9]
sine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#15
180+30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
multiply.html 0 right, 0 wrong, 0 ignored, 0 exceptions
cosine.html 1 right, 0 wrong, 0 ignored, 0 exceptions
#16
30.html 1 right, 0 wrong, 0 ignored, 0 exceptions
multiply.html 0 right, 0 wrong, 0 ignored, 0 exceptions
sine.html 1 right, 0 wrong, 0 ignored, 0 exceptions

To meet the "all pairs" requirement we need at least n X m cases, where n and m are the sizes of the two largest categories. That means with only two categories all combinations and all pairs are the same. The marvel of the all pairs algorithm is that it squeezes draws from additional categories into these same cases and possibly a few more.

fit.Summary
counts 39 right, 9 wrong, 0 ignored, 0 exceptions
counts run 29 right, 3 wrong, 0 ignored, 6 exceptions
input file /Users/ward/Documents/Java/fit/Release/Documents/AllPairs.html
input update Mon Sep 15 16:47:23 PDT 2003
output file /Users/ward/Documents/Java/fit/Release/Reports/AllPairs.html
run date Mon Sep 15 16:51:16 PDT 2003
run elapsed time 0:00.58

Implementation

The algorithm is largely JamesBach's from the source cited on the AllPairsExample page. My implementation can be summarized as follows.

The case currently being filled is called the slug. A pair will fit the slug only if the following hold.

The fixture uses these helper objects to represent the state of the algorithm.

See the source.

See AllPairsAlgorithm for some tests we've written for this algorithm itself.
Last edited November 9, 2002