Upgrade to Go 1.13.4 and set up for use with Go modules

.gitignore

@@ -1,4 +1,2 @@
-/.gopath
 /bin
 /releases
-/vendor/go1.*

Makefile

@@ -1,7 +1,7 @@
 PACKAGE := github.com/github/git-sizer
 ROOTDIR := $(abspath $(CURDIR))
-GOPATH := $(ROOTDIR)/.gopath
-export GOPATH
+GO111MODULES := 1
+export GO111MODULES
 
 GO := $(CURDIR)/script/go
 GOFMT := $(CURDIR)/script/gofmt
@@ -13,12 +13,12 @@ ifdef USE_ISATTY
 GOFLAGS := $(GOFLAGS) --tags isatty
 endif
 
-GO_SRCS := $(sort $(shell cd $(GOPATH)/src/$(PACKAGE) && $(GO) list -f ' \
-	{{$$ip := .ImportPath}} \
-	{{range .GoFiles     }}{{printf ".gopath/src/%s/%s\n" $$ip .}}{{end}} \
-	{{range .CgoFiles    }}{{printf ".gopath/src/%s/%s\n" $$ip .}}{{end}} \
-	{{range .TestGoFiles }}{{printf ".gopath/src/%s/%s\n" $$ip .}}{{end}} \
-	{{range .XTestGoFiles}}{{printf ".gopath/src/%s/%s\n" $$ip .}}{{end}} \
+GO_SRCS := $(sort $(shell $(GO) list -f ' \
+	{{$$ip := .Dir}} \
+	{{range .GoFiles     }}{{printf "%s/%s\n" $$ip .}}{{end}} \
+	{{range .CgoFiles    }}{{printf "%s/%s\n" $$ip .}}{{end}} \
+	{{range .TestGoFiles }}{{printf "%s/%s\n" $$ip .}}{{end}} \
+	{{range .XTestGoFiles}}{{printf "%s/%s\n" $$ip .}}{{end}} \
 	' ./...))
 
 .PHONY: all
@@ -27,7 +27,7 @@ all: bin/git-sizer
 .PHONY: bin/git-sizer
 bin/git-sizer:
 	mkdir -p bin
-	cd $(GOPATH)/src/$(PACKAGE) && $(GO) build $(GOFLAGS) -o $(ROOTDIR)/$@ $(PACKAGE)
+	$(GO) build $(GOFLAGS) -o $(ROOTDIR)/$@ $(PACKAGE)
 
 # Cross-compile for a bunch of common platforms. Note that this
 # doesn't work with USE_ISATTY:
@@ -51,8 +51,7 @@ define PLATFORM_template =
 .PHONY: bin/git-sizer-$(1)-$(2)$(3)
 bin/git-sizer-$(1)-$(2)$(3):
 	mkdir -p bin
-	cd $$(GOPATH)/src/$$(PACKAGE) && \
-		GOOS=$(1) GOARCH=$(2) $$(GO) build $$(GOFLAGS) -ldflags "-X main.ReleaseVersion=$$(VERSION)" -o $$(ROOTDIR)/$$@ $$(PACKAGE)
+	GOOS=$(1) GOARCH=$(2) $$(GO) build $$(GOFLAGS) -ldflags "-X main.ReleaseVersion=$$(VERSION)" -o $$(ROOTDIR)/$$@ $$(PACKAGE)
 common-platforms: bin/git-sizer-$(1)-$(2)$(3)
 
 # Note that releases don't include code from vendor (they're only used
@@ -63,7 +62,8 @@ releases/git-sizer-$$(VERSION)-$(1)-$(2).zip: bin/git-sizer-$(1)-$(2)$(3)
 	mkdir -p releases/tmp-$$(VERSION)-$(1)-$(2)
 	cp README.md LICENSE.md releases/tmp-$$(VERSION)-$(1)-$(2)
 	cp bin/git-sizer-$(1)-$(2)$(3) releases/tmp-$$(VERSION)-$(1)-$(2)/git-sizer$(3)
-	cp vendor/github.com/spf13/pflag/LICENSE releases/tmp-$$(VERSION)-$(1)-$(2)/LICENSE-spf13-pflag
+	cp $$$$($$(GO) list -f '{{.Dir}}' github.com/spf13/pflag)/LICENSE \
+		releases/tmp-$$(VERSION)-$(1)-$(2)/LICENSE-spf13-pflag
 	rm -f $$@
 	zip -j $$@ releases/tmp-$$(VERSION)-$(1)-$(2)/*
 	rm -rf releases/tmp-$$(VERSION)-$(1)-$(2)
@@ -84,7 +84,7 @@ test: bin/git-sizer gotest
 
 .PHONY: gotest
 gotest:
-	cd $(GOPATH)/src/$(PACKAGE) && $(GO) test -timeout 60s $(GOFLAGS) ./...
+	$(GO) test -timeout 60s $(GOFLAGS) ./...
 
 .PHONY: gofmt
 gofmt:
@@ -102,7 +102,7 @@ govet:
 clean:
 	rm -rf bin
 
-# List all of this project's Go sources, excluding vendor, within .gopath:
+# List all of this project's Go sources:
 .PHONY: srcs
 srcs:
 	@printf "%s\n" $(GO_SRCS)

docs/BUILDING.md

@@ -45,14 +45,6 @@ This procedure is intended for experts and people who want to help develop `git-
 
 It is also possible to cross-compile for other platforms that are supported by Go. See the comments in the `Makefile` for more information.
 
-Note that this procedure uses a project-local `GOPATH`. This means that you can clone the repository anywhere. The disadvantage is that Go tools need to know about this `GOPATH`. The `Makefile` and the scripts under `scripts/` take care of this automatically. But if you want to run `go` commands by hand, either first set your `GOPATH`:
-
-    export GOPATH="$(pwd)/.gopath"
-
-Or use `script/go` and `script/gofmt` rather than `go` and `gofmt`, respectively.
-
-Unfortunately, some Go tools get confused by the symlink that is used to make the project-local `GOPATH` work. If you have this problem, it sometimes helps to run such commands from `.gopath/src/github.com/github/git-sizer/`. Alternatively, clone the project into the traditional place in your normal `GOPATH`.
-
 
 ## Making a release
 

go.mod

@@ -0,0 +1,10 @@
+module github.com/github/git-sizer
+
+go 1.13
+
+require (
+	github.com/davecgh/go-spew v1.1.0
+	github.com/pmezard/go-difflib v1.0.0
+	github.com/spf13/pflag v1.0.0
+	github.com/stretchr/testify v1.2.1
+)

go.sum

@@ -0,0 +1,8 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/spf13/pflag v1.0.0 h1:oaPbdDe/x0UncahuwiPxW1GYJyilRAdsPnq3e1yaPcI=
+github.com/spf13/pflag v1.0.0/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/stretchr/testify v1.2.1 h1:52QO5WkIUcHGIR7EnGagH88x1bUzqGXTC5/1bDTUQ7U=
+github.com/stretchr/testify v1.2.1/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=

script/bootstrap

@@ -5,14 +5,8 @@ set -e
 cd "$(dirname "$0")/.."
 
 export ROOTDIR="$(pwd)"
-export GOPATH="$ROOTDIR/.gopath"
 
 if [[ "$(uname -s)" = "Darwin" ]]; then
     brew bundle
 fi
 . script/ensure-go-installed.sh
-
-BASE="$GOPATH/src/github.com/github/git-sizer"
-rm -f "$BASE"
-mkdir -p $(dirname "$BASE")
-ln -s "$(pwd)" "$BASE"

script/ensure-go-installed.sh

@@ -4,17 +4,17 @@ if [ -z "$ROOTDIR" ]; then
     echo 1>&2 'ensure-go-installed.sh invoked without ROOTDIR set!'
 fi
 
-# Is go installed, and at least 1.9?
+# Is go installed, and at least 1.13?
 go_ok() {
     set -- $(go version 2>/dev/null |
                 sed -n 's/.*go\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/\1 \2/p' |
                 head -n 1)
-    [ $# -eq 2 ] && [ "$1" -eq 1 ] && [ "$2" -ge 9 ]
+    [ $# -eq 2 ] && [ "$1" -eq 1 ] && [ "$2" -ge 13 ]
 }
 
 # If a local go is installed, use it.
 set_up_vendored_go() {
-    GO_VERSION=go1.9.2
+    GO_VERSION=go1.13.4
     VENDORED_GOROOT="$ROOTDIR/vendor/$GO_VERSION/go"
     if [ -x "$VENDORED_GOROOT/bin/go" ]; then
         export GOROOT="$VENDORED_GOROOT"

script/go

@@ -4,6 +4,5 @@ set -e
 
 export ROOTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )/.." && pwd )"
 . $ROOTDIR/script/ensure-go-installed.sh
-export GOPATH=$ROOTDIR/.gopath
 
 exec "$(basename $0)" "$@"

script/install-vendored-go

@@ -1,14 +1,14 @@
 #!/bin/sh
 
 # The checksums below must correspond to the downloads for this version.
-GO_VERSION=go1.9.2
+GO_VERSION=go1.13.4
 
 if [ $(uname -s) = "Darwin" ]; then
     GO_PKG=${GO_VERSION}.darwin-amd64.tar.gz
-    GO_PKG_SHA=8b4f6ae6deae1150d2e341d02c247fd18a99af387516540eeb84702ffd76d3a1
+    GO_PKG_SHA=9f0721551a24a1eb43d2005cd58bd7b17574e50384b8da8896b0754259790752
 elif [ $(uname -s) = "Linux" ]; then
     GO_PKG=${GO_VERSION}.linux-amd64.tar.gz
-    GO_PKG_SHA=de874549d9a8d8d8062be05808509c09a88a248e77ec14eb77453530829ac02b
+    GO_PKG_SHA=692d17071736f74be04a72a06dab9cac1cd759377bd85316e52b2227604c004c
 else
     echo 1>&2 "I don't know how to install Go on your platform."
     echo 1>&2 "Please install $GO_VERSION or later and add it to your PATH."