Add tests for custom, fail (bad and unknown) and legacy fetch methods

Also improves the handling of the legacy fetch method. It is now
enabled only for dependencies, and not for the top-level application.
This should force Erlang.mk users to update their definitions.

core/deps.mk

@@ -524,7 +524,7 @@ define dep_fetch
 	$(if $(dep_$(1)), \
 		$(if $(dep_fetch_$(word 1,$(dep_$(1)))), \
 			$(word 1,$(dep_$(1))), \
-			legacy), \
+			$(if $(IS_DEP),legacy,fail)), \
 		$(if $(filter $(1),$(PACKAGES)), \
 			$(pkg_$(1)_fetch), \
 			fail))

test/core_deps.mk

@@ -1,6 +1,6 @@
 # Core: Packages and dependencies.
 
-CORE_DEPS_CASES = build-c-8cc build-c-imagejs build-erl build-js dep-commit doc fetch-cp fetch-git fetch-hex fetch-hg fetch-svn otp pkg rel search shell test
+CORE_DEPS_CASES = build-c-8cc build-c-imagejs build-erl build-js dep-commit doc fetch-cp fetch-custom fetch-fail-bad fetch-fail-unknown fetch-git fetch-hex fetch-hg fetch-legacy fetch-svn otp pkg rel search shell test
 CORE_DEPS_TARGETS = $(addprefix core-deps-,$(CORE_DEPS_CASES))
 CORE_DEPS_CLEAN_TARGETS = $(addprefix clean-,$(CORE_DEPS_TARGETS))
 
@@ -237,6 +237,70 @@ endif
 		true = lists:member(my_dep, Deps), \
 		halt()"
 
+core-deps-fetch-custom: build clean-core-deps-fetch-custom
+
+	$i "Bootstrap a new OTP library named $(APP)"
+	$t mkdir $(APP)/
+	$t cp ../erlang.mk $(APP)/
+	$t $(MAKE) -C $(APP) -f erlang.mk bootstrap-lib $v
+
+	$i "Add dependency boop using custom fetch method beep to the list of dependencies"
+	$t sed -i.bak '2i\
+DEPS = boop\
+dep_boop = beep boop\
+dep_fetch_beep = mkdir -p \$$(DEPS_DIR)/\$$1\
+' $(APP)/Makefile
+
+ifdef LEGACY
+	$i "Add boop to the applications key in the .app.src file"
+	$t sed -i.bak '8i\
+			boop,' $(APP)/src/$(APP).app.src
+endif
+
+	$i "Build the application"
+	$t $(MAKE) -C $(APP) $v
+
+	$i "Check that all dependencies were fetched"
+	$t test -d $(APP)/deps/boop
+
+	$i "Check that the application was compiled correctly"
+	$t $(ERL) -pa $(APP)/ebin/ $(APP)/deps/*/ebin/ -eval " \
+		ok = application:load($(APP)), \
+		{ok, Deps} = application:get_key($(APP), applications), \
+		true = lists:member(boop, Deps), \
+		halt()"
+
+core-deps-fetch-fail-bad: build clean-core-deps-fetch-fail-bad
+
+	$i "Bootstrap a new OTP library named $(APP)"
+	$t mkdir $(APP)/
+	$t cp ../erlang.mk $(APP)/
+	$t $(MAKE) -C $(APP) -f erlang.mk bootstrap-lib $v
+
+	$i "Add Cowlib as a dependency using a non-existing fetch method named oops"
+	$t sed -i.bak '2i\
+DEPS = cowlib\
+dep_cowlib = oops https://github.com/ninenines/cowlib 1.0.0\
+' $(APP)/Makefile
+
+	$i "Check that building the application fails"
+	$t if $(MAKE) -C $(APP) $v; then false; fi
+
+core-deps-fetch-fail-unknown: build clean-core-deps-fetch-fail-unknown
+
+	$i "Bootstrap a new OTP library named $(APP)"
+	$t mkdir $(APP)/
+	$t cp ../erlang.mk $(APP)/
+	$t $(MAKE) -C $(APP) -f erlang.mk bootstrap-lib $v
+
+	$i "Add an unknown application as a dependency"
+	$t sed -i.bak '2i\
+DEPS = unknown\
+' $(APP)/Makefile
+
+	$i "Check that building the application fails"
+	$t if $(MAKE) -C $(APP) $v; then false; fi
+
 core-deps-fetch-git: build clean-core-deps-fetch-git
 
 	$i "Bootstrap a new OTP library named $(APP)"
@@ -340,6 +404,26 @@ endif
 		{ok, \"4.0.3\"} = application:get_key(ehsa, vsn), \
 		halt()"
 
+# Legacy must fail for the top-level application, but work for dependencies.
+core-deps-fetch-legacy: build clean-core-deps-fetch-legacy
+
+	$i "Bootstrap a new OTP library named $(APP)"
+	$t mkdir $(APP)/
+	$t cp ../erlang.mk $(APP)/
+	$t $(MAKE) -C $(APP) -f erlang.mk bootstrap-lib $v
+
+	$i "Add Cowlib as a dependency using a non-existing fetch method named oops"
+	$t sed -i.bak '2i\
+DEPS = cowlib\
+dep_cowlib = https://github.com/ninenines/cowlib 1.0.0\
+' $(APP)/Makefile
+
+	$i "Check that building the application fails"
+	$t if $(MAKE) -C $(APP) $v; then false; fi
+
+	$i "Check that building the application works with IS_DEP=1"
+	$t $(MAKE) -C $(APP) IS_DEP=1 $v
+
 core-deps-fetch-svn: build clean-core-deps-fetch-svn
 
 	$i "Bootstrap a new OTP library named $(APP)"