Research Article

Behaviour Preservation across Code Versions in Erlang

Listing 20

PropEr’s output for the second property.
> orddict_t2:test().
..................................................................................
.................!
Failed: After 100 test(s).
An exception was raised: error:badmatch,false.
Stacktrace: [orddict_t2,’-prop_equivalent_dict_modules/0-fun-0-’,2,
             [file,"orddict_t2.erl",line,39],
       lists,foldl,3,[file,"lists.erl",line,1263],
       orddict_t2,’-prop_equivalent_dict_modules/0-fun-1-’,1,
             [file,"orddict_t2.erl",line,37]].
[2.50411088062667,-7.851645940978741,1,<<239,224,172,126>>,
-0.6360219784877551,4,1,<<177,118,23,95,55>>],[store,fetch,fetch,find]
Shrinking........(8 time(s))
[1,false,1,0],[is_key]
false