Add support for SPM test targets

[jnordberg]

I have a iOS project setup with the swift-code standard template and the imports work fine but in the test target I get a No such module error.

[helje5]

Hm, well, I guess support for "Include Unit Tests" and "Include UI Tests" could be added to the app template (as supported by the regular templates).

If you look at the Build Settings of the app target, you can see the settings required to make it work in the test target, you should be able to just copy/paste them. Seems to be:

OTHER_LDFLAGS = $(inherited) -lXcodeSPMDependencies
HEADER_SEARCH_PATHS = $(SRCROOT)/$(PRODUCT_NAME)/.buildzz/.build/Xcode/$(CURRENT_ARCH)-apple-$(SWIFT_PLATFORM_TARGET_PREFIX)$($(DEPLOYMENT_TARGET_SETTING_NAME))/$(CONFIGURATION) $(SRCROOT)/$(PRODUCT_NAME)/.buildzz/.build/Xcode/$(PLATFORM_PREFERRED_ARCH)-apple-$(SWIFT_PLATFORM_TARGET_PREFIX)$($(DEPLOYMENT_TARGET_SETTING_NAME))/$(CONFIGURATION)
LIBRARY_SEARCH_PATHS = $(SRCROOT)/$(PRODUCT_NAME)/.buildzz/.build/Xcode/$(CURRENT_ARCH)-apple-$(SWIFT_PLATFORM_TARGET_PREFIX)$($(DEPLOYMENT_TARGET_SETTING_NAME))/$(CONFIGURATION) $(SRCROOT)/$(PRODUCT_NAME)/.buildzz/.build/Xcode/$(PLATFORM_PREFERRED_ARCH)-apple-$(SWIFT_PLATFORM_TARGET_PREFIX)$($(DEPLOYMENT_TARGET_SETTING_NAME))/$(CONFIGURATION)
SWIFT_INCLUDE_PATHS = $(SRCROOT)/$(PRODUCT_NAME)/.buildzz/.build/$(CURRENT_ARCH)-apple-$(SWIFT_PLATFORM_TARGET_PREFIX)$($(DEPLOYMENT_TARGET_SETTING_NAME))/$(CONFIGURATION) $(SRCROOT)/$(PRODUCT_NAME)/.buildzz/.build/$(PLATFORM_PREFERRED_ARCH)-apple-$(SWIFT_PLATFORM_TARGET_PREFIX)$($(DEPLOYMENT_TARGET_SETTING_NAME))/$(CONFIGURATION)

(you have to replace $(PRODUCT_NAME) with the name of test app you test (which will have the dependencies)).