Run `go vet` on all the Go packages in a directory, then run all their tests, writing test coverage reports to `coverage/pkg.path.out`

makefile

SUBPACKAGES := $(foreach pkg,$(sort $(dir $(shell find . -type f -name '*.go'))),$(patsubst %/,%,${pkg}))

# run tests with coverage reports.
test:
	@${GO} vet ./...
	@mkdir -p coverage
	@for pkg in ${SUBPACKAGES}; do \
		go test $$pkg -v -coverprofile=coverage/$${pkg/\//.}.out; \
	done