Add initial plugin for proper

Should act the same way as the Triq plugin, making switching
mostly painless, excluding the differences between the two
libraries.

build.config

@@ -30,6 +30,7 @@ plugins/edoc
 plugins/erlydtl
 plugins/escript
 plugins/eunit
+plugins/proper
 plugins/relx
 plugins/shell
 plugins/syntastic

plugins/proper.mk

@@ -0,0 +1,53 @@
+# Copyright (c) 2015-2017, Loïc Hoguin <essen@ninenines.eu>
+# This file is part of erlang.mk and subject to the terms of the ISC License.
+
+ifeq ($(filter proper,$(DEPS) $(TEST_DEPS)),proper)
+.PHONY: proper
+
+# Targets.
+
+tests:: proper
+
+define proper_check.erl
+	code:add_pathsa(["$(call core_native_path,$(CURDIR)/ebin)", "$(call core_native_path,$(DEPS_DIR)/*/ebin)"]),
+	Module = fun(M) ->
+		[true] =:= lists:usort([
+			case atom_to_list(F) of
+				"prop_" ++ _ ->
+					io:format("Testing ~p:~p/0~n", [M, F]),
+					proper:quickcheck(M:F());
+				_ ->
+					true
+			end
+		|| {F, 0} <- M:module_info(exports)])
+	end,
+	try
+		case $(1) of
+			all -> [true] =:= lists:usort([Module(M) || M <- [$(call comma_list,$(3))]]);
+			module -> Module($(2));
+			function -> proper:quickcheck($(2))
+		end
+	of
+		true -> halt(0);
+		_ -> halt(1)
+	catch error:undef ->
+		io:format("Undefined property or module?~n~p~n", [erlang:get_stacktrace()]),
+		halt(0)
+	end.
+endef
+
+ifdef t
+ifeq (,$(findstring :,$(t)))
+proper: test-build
+	$(verbose) $(call erlang,$(call proper_check.erl,module,$(t)))
+else
+proper: test-build
+	$(verbose) echo Testing $(t)/0
+	$(verbose) $(call erlang,$(call proper_check.erl,function,$(t)()))
+endif
+else
+proper: test-build
+	$(eval MODULES := $(patsubst %,'%',$(sort $(notdir $(basename $(wildcard ebin/*.beam))))))
+	$(gen_verbose) $(call erlang,$(call proper_check.erl,all,undefined,$(MODULES)))
+endif
+endif

plugins/triq.mk

@@ -20,7 +20,7 @@ define triq_check.erl
 		true -> halt(0);
 		_ -> halt(1)
 	catch error:undef ->
-		io:format("Undefined property or module~n"),
+		io:format("Undefined property or module?~n~p~n", [erlang:get_stacktrace()]),
 		halt(0)
 	end.
 endef