Print StringToInt and StringToInt64 defaults in sorted order

string_to_int.go

@@ -3,6 +3,7 @@ package pflag
 import (
 	"bytes"
 	"fmt"
+	"sort"
 	"strconv"
 	"strings"
 )
@@ -51,16 +52,21 @@ func (s *stringToIntValue) Type() string {
 }
 
 func (s *stringToIntValue) String() string {
+	keys := make([]string, 0, len(*s.value))
+	for k := range *s.value {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
 	var buf bytes.Buffer
-	i := 0
-	for k, v := range *s.value {
+	for i, k := range keys {
 		if i > 0 {
 			buf.WriteRune(',')
 		}
+		v := (*s.value)[k]
 		buf.WriteString(k)
 		buf.WriteRune('=')
 		buf.WriteString(strconv.Itoa(v))
-		i++
 	}
 	return "[" + buf.String() + "]"
 }

string_to_int64.go

@@ -3,6 +3,7 @@ package pflag
 import (
 	"bytes"
 	"fmt"
+	"sort"
 	"strconv"
 	"strings"
 )
@@ -51,16 +52,21 @@ func (s *stringToInt64Value) Type() string {
 }
 
 func (s *stringToInt64Value) String() string {
+	keys := make([]string, 0, len(*s.value))
+	for k := range *s.value {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
 	var buf bytes.Buffer
-	i := 0
-	for k, v := range *s.value {
+	for i, k := range keys {
 		if i > 0 {
 			buf.WriteRune(',')
 		}
+		v := (*s.value)[k]
 		buf.WriteString(k)
 		buf.WriteRune('=')
 		buf.WriteString(strconv.FormatInt(v, 10))
-		i++
 	}
 	return "[" + buf.String() + "]"
 }

string_to_int64_test.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"fmt"
 	"strconv"
+	"strings"
 	"testing"
 )
 
@@ -154,3 +155,20 @@ func TestS2I64CalledTwice(t *testing.T) {
 		}
 	}
 }
+
+func TestS2I64UsageSorted(t *testing.T) {
+	var s2i map[string]int64
+	f := NewFlagSet("test", ContinueOnError)
+	f.StringToInt64Var(&s2i, "s2i", map[string]int64{"c": 3, "a": 1, "d": 4, "b": 2}, "usage")
+
+	want := "[a=1,b=2,c=3,d=4]"
+	// Map iteration order is randomized, so check repeatedly.
+	for i := 0; i < 100; i++ {
+		if got := f.Lookup("s2i").Value.String(); got != want {
+			t.Fatalf("expected String() to be %q but got: %q", want, got)
+		}
+		if usage := f.FlagUsages(); !strings.Contains(usage, "(default "+want+")") {
+			t.Fatalf("expected usage to contain default %s but got: %q", want, usage)
+		}
+	}
+}

string_to_int_test.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"fmt"
 	"strconv"
+	"strings"
 	"testing"
 )
 
@@ -154,3 +155,20 @@ func TestS2ICalledTwice(t *testing.T) {
 		}
 	}
 }
+
+func TestS2IUsageSorted(t *testing.T) {
+	var s2i map[string]int
+	f := NewFlagSet("test", ContinueOnError)
+	f.StringToIntVar(&s2i, "s2i", map[string]int{"c": 3, "a": 1, "d": 4, "b": 2}, "usage")
+
+	want := "[a=1,b=2,c=3,d=4]"
+	// Map iteration order is randomized, so check repeatedly.
+	for i := 0; i < 100; i++ {
+		if got := f.Lookup("s2i").Value.String(); got != want {
+			t.Fatalf("expected String() to be %q but got: %q", want, got)
+		}
+		if usage := f.FlagUsages(); !strings.Contains(usage, "(default "+want+")") {
+			t.Fatalf("expected usage to contain default %s but got: %q", want, usage)
+		}
+	}
+}