Add a PropEr test for cowboy_dispatcher:split_host/1

Mostly thanks to Magnus Klaar as it took me a while to figure
out how PropEr tests had to be written.

2 files changed, 105 insertions, 0 deletions

diff --git a/test/dispatcher_prop.erl b/test/dispatcher_prop.erl
new file mode 100644
index 0000000..b6a1c92
--- /dev/null
+++ b/test/dispatcher_prop.erl
@@ -0,0 +1,68 @@
+%% Copyright (c) 2011, Magnus Klaar <[email protected]>
+%% Copyright (c) 2011, Loïc Hoguin <[email protected]>
+%%
+%% Permission to use, copy, modify, and/or distribute this software for any
+%% purpose with or without fee is hereby granted, provided that the above
+%% copyright notice and this permission notice appear in all copies.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+-module(dispatcher_prop).
+-include_lib("proper/include/proper.hrl").
+
+%% Generators.
+
+hostname_head_char() ->
+	oneof([choose($a, $z), choose($A, $Z), choose($0, $9)]).
+
+hostname_char() ->
+	oneof([choose($a, $z), choose($A, $Z), choose($0, $9), $-]).
+
+hostname_label() ->
+	?SUCHTHAT(Label, [hostname_head_char()|list(hostname_char())],
+		length(Label) < 64).
+
+hostname() ->
+	?SUCHTHAT(Hostname,
+		?LET(Labels, list(hostname_label()), string:join(Labels, ".")),
+		length(Hostname) > 0 andalso length(Hostname) =< 255).
+
+port_number() ->
+	choose(1, 16#ffff).
+
+port_str() ->
+	oneof(["", ?LET(Port, port_number(), ":" ++ integer_to_list(Port))]).
+
+server() ->
+	?LET({Hostname, PortStr}, {hostname(), port_str()},
+		list_to_binary(Hostname ++ PortStr)).
+
+%% Properties.
+
+prop_split_host_symmetric() ->
+	?FORALL(Server, server(),
+	begin case cowboy_dispatcher:split_host(Server) of
+			{Tokens, RawHost, undefined} ->
+				(Server == RawHost) and (Server == binary_join(Tokens, "."));
+			{Tokens, RawHost, Port} ->
+				PortBin = (list_to_binary(":" ++ integer_to_list(Port))),
+				(Server == << RawHost/binary, PortBin/binary >>)
+				and (Server == << (binary_join(Tokens, "."))/binary,
+					PortBin/binary >>)
+	end end).
+
+%% Internal.
+
+%% Contributed by MononcQc on #erlounge.
+binary_join(Flowers, Leaf) ->
+	case Flowers of
+		[] -> <<>>;
+		[Petal|Pot] -> iolist_to_binary(
+			[Petal | [[Leaf | Pollen] || Pollen <- Pot]])
+	end.
diff --git a/test/proper_SUITE.erl b/test/proper_SUITE.erl
new file mode 100644
index 0000000..440aa5f
--- /dev/null
+++ b/test/proper_SUITE.erl
@@ -0,0 +1,37 @@
+%% Copyright (c) 2011, Loïc Hoguin <[email protected]>
+%%
+%% Permission to use, copy, modify, and/or distribute this software for any
+%% purpose with or without fee is hereby granted, provided that the above
+%% copyright notice and this permission notice appear in all copies.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+-module(proper_SUITE).
+
+-include_lib("common_test/include/ct.hrl").
+
+-export([all/0, groups/0]). %% ct.
+-export([dispatcher_split_host/1]). %% cowboy_dispatcher.
+
+%% ct.
+
+all() ->
+	[{group, dispatcher}].
+
+groups() ->
+	[{dispatcher, [], [dispatcher_split_host]}].
+
+%% cowboy_dispatcher.
+
+dispatcher_split_host(_Config) ->
+	true = proper:quickcheck(dispatcher_prop:prop_split_host_symmetric(),
+		[{on_output, fun(Format, Data) ->
+			io:format(user, Format, Data), %% Console.
+			io:format(Format, Data) %% Logs.
+		end}]).