fs: fix option types printing incorrectly for backend flags

Before this change backend types were printing incorrectly as the name
of the type, not what was defined by the Type() method.

This was not working due to not calling the Type() method. However
this needed to be defined on a non-pointer type due to the way the
options are handled.

fs/bwtimetable_test.go

@@ -9,8 +9,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*BwTimetable)(nil)
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*BwTimetable)(nil)
+	_ flaggerNP = BwTimetable{}
+)
 
 func TestBwTimetableSet(t *testing.T) {
 	for _, test := range []struct {

fs/countsuffix.go

@@ -154,7 +154,7 @@ func (x *CountSuffix) Set(s string) error {
 }
 
 // Type of the value
-func (x *CountSuffix) Type() string {
+func (x CountSuffix) Type() string {
 	return "CountSuffix"
 }
 

fs/countsuffix_test.go

@@ -9,8 +9,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*CountSuffix)(nil)
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*CountSuffix)(nil)
+	_ flaggerNP = CountSuffix(0)
+)
 
 func TestCountSuffixString(t *testing.T) {
 	for _, test := range []struct {

fs/cutoffmode.go

@@ -42,7 +42,7 @@ func (m *CutoffMode) Set(s string) error {
 }
 
 // Type of the value
-func (m *CutoffMode) Type() string {
+func (m CutoffMode) Type() string {
 	return "string"
 }
 

fs/cutoffmode_test.go

@@ -9,8 +9,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*CutoffMode)(nil)
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*CutoffMode)(nil)
+	_ flaggerNP = CutoffMode(0)
+)
 
 func TestCutoffModeString(t *testing.T) {
 	for _, test := range []struct {

fs/dump.go

@@ -86,7 +86,7 @@ func (f *DumpFlags) Set(s string) error {
 }
 
 // Type of the value
-func (f *DumpFlags) Type() string {
+func (f DumpFlags) Type() string {
 	return "DumpFlags"
 }
 

fs/dump_test.go

@@ -8,8 +8,11 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*DumpFlags)(nil)
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*DumpFlags)(nil)
+	_ flaggerNP = DumpFlags(0)
+)
 
 func TestDumpFlagsString(t *testing.T) {
 	assert.Equal(t, "", DumpFlags(0).String())

fs/log.go

@@ -65,8 +65,8 @@ func (l *LogLevel) Set(s string) error {
 }
 
 // Type of the value
-func (l *LogLevel) Type() string {
-	return "string"
+func (l LogLevel) Type() string {
+	return "LogLevel"
 }
 
 // UnmarshalJSON makes sure the value can be parsed as a string or integer in JSON

fs/log_test.go

@@ -10,9 +10,12 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*LogLevel)(nil)
-var _ fmt.Stringer = LogValueItem{}
+// Check it satisfies the interfac(
+var (
+	_ flagger      = (*LogLevel)(nil)
+	_ flaggerNP    = LogLevel(0)
+	_ fmt.Stringer = LogValueItem{}
+)
 
 type withString struct{}
 

fs/parseduration_test.go

@@ -11,8 +11,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*Duration)(nil)
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*Duration)(nil)
+	_ flaggerNP = Duration(0)
+)
 
 func TestParseDuration(t *testing.T) {
 	now := time.Date(2020, 9, 5, 8, 15, 5, 250, time.UTC)

fs/parsetime_test.go

@@ -10,8 +10,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*Time)(nil)
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*Time)(nil)
+	_ flaggerNP = Time{}
+)
 
 func TestParseTime(t *testing.T) {
 	now := time.Date(2020, 9, 5, 8, 15, 5, 250, time.UTC)

fs/registry.go

@@ -207,9 +207,20 @@ func (o *Option) Set(s string) (err error) {
 	return nil
 }
 
+type typer interface {
+	Type() string
+}
+
 // Type of the value
 func (o *Option) Type() string {
-	return reflect.TypeOf(o.GetValue()).Name()
+	v := o.GetValue()
+
+	// Try to call Type method on non-pointer
+	if do, ok := v.(typer); ok {
+		return do.Type()
+	}
+
+	return reflect.TypeOf(v).Name()
 }
 
 // FlagName for the option

fs/sizesuffix.go

@@ -192,7 +192,7 @@ func (x *SizeSuffix) Set(s string) error {
 }
 
 // Type of the value
-func (x *SizeSuffix) Type() string {
+func (x SizeSuffix) Type() string {
 	return "SizeSuffix"
 }
 

fs/sizesuffix_test.go

@@ -17,8 +17,20 @@ type flagger interface {
 	json.Unmarshaler
 }
 
-// Check it satisfies the interface
-var _ flagger = (*SizeSuffix)(nil)
+// Interface which non-pointer flags must satisfy
+//
+// These are from pflag.Value and need to be non-pointer due the the
+// way the backend flags are inserted into the flags.
+type flaggerNP interface {
+	String() string
+	Type() string
+}
+
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*SizeSuffix)(nil)
+	_ flaggerNP = SizeSuffix(0)
+)
 
 func TestSizeSuffixString(t *testing.T) {
 	for _, test := range []struct {

fs/tristate_test.go

@@ -9,8 +9,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// Check it satisfies the interface
-var _ flagger = (*Tristate)(nil)
+// Check it satisfies the interfaces
+var (
+	_ flagger   = (*Tristate)(nil)
+	_ flaggerNP = Tristate{}
+)
 
 func TestTristateString(t *testing.T) {
 	for _, test := range []struct {