Add test-only dependencies

2 files changed, 19 insertions, 1 deletions

diff --git a/README.md b/README.md
index 263c78d..e5596e9 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,18 @@ dep_bullet = https://github.com/extend/bullet.git 0.4.1
 
 They will always be compiled using the command `make`.
 
+You can also specify test-only dependencies. These dependencies will only
+be downloaded when running `make tests`. The format is the same as above,
+except the variable `TEST_DEPS` holds the list of test-only dependencies.
+
+``` erlang
+TEST_DEPS = ct_helper
+dep_ct_helper = https://github.com/extend/ct_helper.git master
+```
+
+Please note that the test dependencies will only be compiled once
+when they are fetched, unlike the normal dependencies.
+
 Commands
 --------
 
diff --git a/erlang.mk b/erlang.mk
index 0ac0f3f..9e4c698 100644
--- a/erlang.mk
+++ b/erlang.mk
@@ -34,6 +34,7 @@ DEPS_DIR ?= $(CURDIR)/deps
 export DEPS_DIR
 
 ALL_DEPS_DIRS = $(addprefix $(DEPS_DIR)/,$(DEPS))
+ALL_TEST_DEPS_DIRS = $(addprefix $(DEPS_DIR)/,$(TEST_DEPS))
 
 # Application.
 
@@ -94,7 +95,12 @@ clean-docs:
 
 # Tests.
 
-build-tests:
+$(foreach dep,$(TEST_DEPS),$(eval $(call dep_target,$(dep))))
+
+build-test-deps: $(ALL_TEST_DEPS_DIRS)
+	@for dep in $(ALL_TEST_DEPS_DIRS) ; do $(MAKE) -C $$dep; done
+
+build-tests: build-test-deps
 	$(gen_verbose) erlc -v $(ERLC_OPTS) -o test/ \
 		$(wildcard test/*.erl test/*/*.erl) -pa ebin/