Implement POSIX/GNU style flags

Use package `spf13/pflag` for flag processing, so that they respect
the POSIX/GNU conventions that prevail everywhere else in the universe
rather than Go's gratuitously different conventions.

Author: mhagger

Gopkg.lock

@@ -7,3 +7,7 @@
   unused-packages = true
   go-tests = true
   non-go = true
+
+[[constraint]]
+  name = "github.com/spf13/pflag"
+  version = "1.0.0"

Gopkg.toml

@@ -63,6 +63,7 @@ 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-$$(VERSION)-$(1)-$(2)/LICENSE-spf13-pflag
 	rm -f $$@
 	zip -j $$@ releases/tmp-$$(VERSION)-$(1)-$(2)/*
 	rm -rf releases/tmp-$$(VERSION)-$(1)-$(2)

Makefile

@@ -3,7 +3,6 @@ package main
 import (
 	"encoding/json"
 	"errors"
-	"flag"
 	"fmt"
 	"io"
 	"os"
@@ -13,6 +12,8 @@ import (
 	"github.com/github/git-sizer/git"
 	"github.com/github/git-sizer/isatty"
 	"github.com/github/git-sizer/sizes"
+
+	"github.com/spf13/pflag"
 )
 
 type NegatedBoolValue struct {
@@ -37,8 +38,8 @@ func (b *NegatedBoolValue) String() string {
 	}
 }
 
-func (v *NegatedBoolValue) IsBoolFlag() bool {
-	return true
+func (v *NegatedBoolValue) Type() string {
+	return "bool"
 }
 
 func main() {
@@ -59,43 +60,45 @@ func mainImplementation() error {
 	var threshold sizes.Threshold = 1
 	var progress bool
 
-	flag.BoolVar(&processBranches, "branches", false, "process all branches")
-	flag.BoolVar(&processTags, "tags", false, "process all tags")
-	flag.BoolVar(&processRemotes, "remotes", false, "process all remote-tracking branches")
-	flag.Var(
+	pflag.BoolVar(&processBranches, "branches", false, "process all branches")
+	pflag.BoolVar(&processTags, "tags", false, "process all tags")
+	pflag.BoolVar(&processRemotes, "remotes", false, "process all remote-tracking branches")
+	pflag.Var(
 		&threshold, "threshold",
 		"minimum level of concern (i.e., number of stars) that should be\n"+
-			"        reported",
+			"                              reported",
 	)
-	flag.Var(
+	pflag.Var(
 		sizes.NewThresholdFlagValue(&threshold, 30),
 		"critical", "only report critical statistics",
 	)
-	flag.Var(
+	pflag.Lookup("critical").NoOptDefVal = "true"
+	pflag.Var(
 		sizes.NewThresholdFlagValue(&threshold, 0),
 		"verbose", "report all statistics, whether concerning or not",
 	)
-	flag.Var(
+	pflag.Lookup("verbose").NoOptDefVal = "true"
+	pflag.Var(
 		&nameStyle, "names",
 		"display names of large objects in the specified `style`:\n"+
-			"            --names=none        omit footnotes entirely\n"+
-			"            --names=hash        show only the SHA-1s of objects\n"+
-			"            --names=full        show full names",
+			"        --names=none            omit footnotes entirely\n"+
+			"        --names=hash            show only the SHA-1s of objects\n"+
+			"        --names=full            show full names",
 	)
-	flag.BoolVar(&jsonOutput, "json", false, "output results in JSON format")
-	flag.BoolVar(&jsonOutput, "j", false, "output results in JSON format")
+	pflag.BoolVarP(&jsonOutput, "json", "j", false, "output results in JSON format")
 
 	atty, err := isatty.Isatty(os.Stderr.Fd())
 	if err != nil {
 		atty = false
 	}
 
-	flag.BoolVar(&progress, "progress", atty, "report progress to stderr")
-	flag.Var(&NegatedBoolValue{&progress}, "no-progress", "suppress progress output")
+	pflag.BoolVar(&progress, "progress", atty, "report progress to stderr")
+	pflag.Var(&NegatedBoolValue{&progress}, "no-progress", "suppress progress output")
+	pflag.Lookup("no-progress").NoOptDefVal = "true"
 
-	flag.StringVar(&cpuprofile, "cpuprofile", "", "write cpu profile to file")
+	pflag.StringVar(&cpuprofile, "cpuprofile", "", "write cpu profile to file")
 
-	flag.Parse()
+	pflag.Parse()
 
 	if cpuprofile != "" {
 		f, err := os.Create(cpuprofile)
@@ -106,7 +109,7 @@ func mainImplementation() error {
 		defer pprof.StopCPUProfile()
 	}
 
-	args := flag.Args()
+	args := pflag.Args()
 
 	if len(args) != 0 {
 		return errors.New("excess arguments")

git-sizer.go

@@ -2,13 +2,14 @@ package sizes
 
 import (
 	"bytes"
-	"flag"
 	"fmt"
 	"io"
 	"strconv"
 
 	"github.com/github/git-sizer/counts"
 	"github.com/github/git-sizer/git"
+
+	"github.com/spf13/pflag"
 )
 
 func (s BlobSize) String() string {
@@ -200,7 +201,7 @@ func (l *item) levelOfConcern(t *table) (string, bool) {
 
 type Threshold float64
 
-// Methods to implement flag.Value:
+// Methods to implement pflag.Value:
 func (t *Threshold) String() string {
 	if t == nil {
 		return "UNSET"
@@ -227,10 +228,14 @@ func (t *Threshold) Set(s string) error {
 	return nil
 }
 
-// A `flag.Value` that can be used as a boolean option that sets a
+func (t *Threshold) Type() string {
+	return "threshold"
+}
+
+// A `pflag.Value` that can be used as a boolean option that sets a
 // `Threshold` variable to a fixed value. For example,
 //
-//		flag.Var(
+//		pflag.Var(
 //			sizes.NewThresholdFlagValue(&threshold, 30),
 //			"critical", "only report critical statistics",
 //		)
@@ -242,14 +247,10 @@ type thresholdFlagValue struct {
 	value     Threshold
 }
 
-func NewThresholdFlagValue(threshold *Threshold, value Threshold) flag.Value {
+func NewThresholdFlagValue(threshold *Threshold, value Threshold) pflag.Value {
 	return &thresholdFlagValue{false, threshold, value}
 }
 
-func (v *thresholdFlagValue) IsBoolFlag() bool {
-	return true
-}
-
 func (v *thresholdFlagValue) String() string {
 	return strconv.FormatBool(v.b)
 }
@@ -268,6 +269,10 @@ func (v *thresholdFlagValue) Set(s string) error {
 	return nil
 }
 
+func (v *thresholdFlagValue) Type() string {
+	return "bool"
+}
+
 type NameStyle int
 
 const (
@@ -276,7 +281,7 @@ const (
 	NameStyleFull
 )
 
-// Methods to implement flag.Value:
+// Methods to implement pflag.Value:
 func (n *NameStyle) String() string {
 	if n == nil {
 		return "UNSET"
@@ -308,6 +313,10 @@ func (n *NameStyle) Set(s string) error {
 	return nil
 }
 
+func (n *NameStyle) Type() string {
+	return "nameStyle"
+}
+
 type table struct {
 	contents        tableContents
 	threshold       Threshold