go-mod.mk: Add more tests (and fix discovered issues)

go-mod.mk

@@ -107,10 +107,12 @@ endif
     # Example: $(call _go.files2dirs,foo/bar/baz foo/baz/qux) => foo foo/bar foo/bar/baz foo/baz foo/baz/qux
     _go.files2dirs = $(sort $(foreach f,$1,$(call _go.file2dirs,$f)))
   # Without pruning sub-module packages (relative to ".", without "./" prefix")
+    # Use pwd(1) instead of $(CURDIR) because $(CURDIR) behaves differently than `go` in the presence of symlinks.
+    _go.raw.cwd := $(shell pwd)
     # Usage: $(call _go.raw.list,ARGS)
-    _go.raw.list = $(call path.trimprefix,_$(CURDIR),$(shell GOPATH=/bogus GO111MODULE=off go list $1))
+    _go.raw.list = $(call path.trimprefix,_$(_go.raw.cwd),$(shell GOPATH=/bogus GO111MODULE=off go list $1))
     _go.raw.pkgs := $(call _go.raw.list,./... 2>/dev/null)
-    _go.raw.submods := $(patsubst %/go.mod,%,$(wildcard $(addsuffix /go.mod,$(call _go.files2dirs,$(_go.raw.pkgs)))))
+    _go.raw.submods := $(filter-out .,$(patsubst %/go.mod,%,$(wildcard $(addsuffix /go.mod,$(call _go.files2dirs,$(_go.raw.pkgs))))))
   # With pruning sub-module packages (relative to ".", without "./" prefix")
     _go.pkgs = $(filter-out $(foreach m,$(_go.raw.submods),$m $m/%),$(_go.raw.pkgs))
     # Usage: $(call _go.list,ARGS)
@@ -133,7 +135,7 @@ go-get: $(go.lock)
 vendor: go-get FORCE
 vendor: $(go.lock)
 	$(go.lock)go mod vendor
-	@test -d $@
+	@test -d $@ || test "$$(go mod edit -json|jq '.Require|length')" -eq 0
 
 $(dir $(_go-mod.mk))go1%.src.tar.gz:
 	curl -o $@ --fail https://dl.google.com/go/$(@F)

tests/go-mod.bats

@@ -16,3 +16,95 @@ setup() {
 	check_go_executable go-mod.mk GOLANGCI_LINT
 	# TODO: Check that $GOLANGCI_LINT behaves correctly
 }
+
+@test "go-mod.mk: go.lock" {
+	cat >>Makefile <<-'__EOT__'
+		include build-aux/go-mod.mk
+		$(info outside: $(go.lock))
+		all: ; @echo 'inside: $(go.lock)'
+	__EOT__
+
+	if [[ "$build_aux_unsupported_go" == true ]] || ! type go &>/dev/null; then
+		make_expecting_go_error
+		return 0
+	fi
+
+	make >actual
+	if [[ "$(go version)" != *' go1.11'* ]]; then
+		printf '%s\n' >expected \
+		       "outside: " \
+		       "inside: "
+		diff -u expected actual
+	else
+		[[ $(sed -n 1p actual) == 'outside: '* ]]
+		[[ $(sed -n 2p actual) == 'inside: '* ]]
+		[[ $(wc -l <actual) -eq 2 ]]
+
+		outside="$(sed -n 's/^outside: //p' actual)"
+		[[ "$outside" != *' '* ]]
+		[[ "$outside" == */flock ]]
+
+		inside="$(sed -n 's/^inside: //p' actual)"
+		read -ra inside_split <<<"$inside"
+		[[ "${#inside_split[@]}" -eq 2 ]]
+		[[ "${inside_split[0]}" == */flock ]]
+		[[ "${inside_split[1]}" == "$(go env GOPATH)/pkg/mod" ]]
+	fi
+}
+
+@test "go-mod.mk: build timestamps" {
+	cat >>Makefile <<-'__EOT__'
+		include build-aux/go-mod.mk
+		all: build
+	__EOT__
+
+	cat >main.go <<-'__EOT__'
+		package main
+
+		func main() {}
+	__EOT__
+
+	mkdir sub
+	cat >sub/main.go <<-'__EOT__'
+		package main
+
+		func main() {}
+	__EOT__
+
+	if [[ "$build_aux_unsupported_go" == true ]] || ! type go &>/dev/null; then
+		make_expecting_go_error
+		return 0
+	fi
+
+	mainexe="bin_$(go env GOHOSTOS)_$(go env GOHOSTARCH)/testlocal"
+	subexe="bin_$(go env GOHOSTOS)_$(go env GOHOSTARCH)/sub"
+
+	make
+
+	[[ -f "$subexe" && -x "$subexe" ]]
+	cp -a "$subexe" subexe.bak
+	[[ ! "$subexe" -nt subexe.bak ]]
+
+	[[ -f "$mainexe" && -x "$mainexe" ]]
+	cp -a "$mainexe" mainexe.bak
+	[[ ! "$mainexe" -nt mainexe.bak ]]
+
+	sleep 2
+
+	cat >sub/main.go <<-'__EOT__'
+		package main
+
+		import "fmt"
+
+		func main() { fmt.Println("Hello world") }
+	__EOT__
+
+	unset CI
+	make
+
+	[[ -f "$subexe" && -x "$subexe" ]]
+	[[ "$subexe" -nt subexe.bak ]]
+
+	[[ -f "$mainexe" && -x "$mainexe" ]]
+	[[ ! "$mainexe" -nt mainexe.bak ]]
+}