Merge

05_proper.asciidoc

@@ -210,3 +210,33 @@ The other issue is that both proper and eunit define a macro
 include proper before eunit, or you could just have the PropER and
 EUnit tests in seperate modules.
 
+
+=== Using Proper for Integration tests
+
+So far we have covered the case where we are using Proper For what is
+in effect unit testing, where we want to ensure that the logic of some
+application is correct.
+
+But what if we wish to ensure that for example our connection to the
+database is working well. In this case we have an obvious set of
+properties that we can exploit, in that we can test that the round
+trip to the database works. If we Create a Record, write it to the
+database, then read it back from the database it should be the same
+(with the possible excpetion of ID columns and timestamps.
+
+In doing this for the Chicago Boss I discovered a major bug in the
+MySQL integration. I found that the escaping of strings was not being
+done correctly. If you saved the string "\\ " it would strip out the 2
+backslashes. I don't think I would have found this by manual testing
+but proper found it in the first block of 100 tests. It actually found
+it in a much larger string, but then reduced it down to the "\\ " that
+I was able to test. Once I had found the problem then actually solving
+it was pretty easy.
+
+As for how I solved it I connected boss to a mysql virtual machine
+and had a table with the correct fields. Then I used this 
+
+[source,erlang]
+----
+include::proper/mysql_test.erl]
+----

proper/mysql_test.erl

@@ -0,0 +1,59 @@
+-module(mysql_test).
+-compile(export_all).
+-include("deps/proper/include/proper.hrl").
+
+
+
+runp() ->
+    runp(100).
+
+runp(N) ->
+    proper:quickcheck(prop_postgres_update_round_trip(),[N]),
+    ok.
+
+-type ascii_char() ::32..126.
+prop_postgres_round_trip() ->
+    ?FORALL({Text, Integer, Bool, Float, Date,Bytea},
+            {list(ascii_char()),
+             integer(),
+             boolean(),
+             float(),
+             date(),binary()},
+            ?IMPLIES(calendar:valid_date(Date),
+                     ?IMPLIES(length(Text) > 1,
+                              begin
+                                  test_round_trip({tb(Text),Integer, Bool, Float, Date, Bytea})
+                              end))).
+test_round_trip({Text,Integer, Bool, Float, Date, Bytea}) ->
+    Rec        = db_test:new(id, Text, Integer, Bool, Float, Date, Bytea),
+
+    {ok, Rec2} = Rec:save(),
+
+    [R|_]      = boss_db:find(db_test, [{text, 'equals', Text}]),
+    io:format( "<-- ~p~n--> ~p~n~n",[Rec2, R]),
+
+    Res = all([
+               R:id()         =:= Rec2:id(),
+               tb(R:text())   =:= tb(Rec:text()),
+               R:integer()    =:= Rec:integer(),
+               cb(R:bool())   =:= Rec:bool(),
+               1.0* R:float() =:= Rec:float(),
+               R:date()       =:= {date,Rec:date()},
+               R:bytea()      =:= Rec:bytea()]),
+    boss_db:delete(Rec2:id()),    
+    Res.
+
+cb(0) ->
+    false;
+cb(_) ->
+    true.
+
+all(L) ->
+    lists:all(fun(X) ->
+                      X
+              end, L).
+
+tb(X) when is_list(X) ->
+    list_to_binary(X);
+tb(X) when is_binary(X) ->
+    X.