Add tests

Author: dearchap

flag_impl.go

@@ -92,7 +92,7 @@ type FlagBase[T any, C any, VC ValueCreator[T, C]] struct {
 // GetValue returns the flags value as string representation and an empty
 // string if the flag takes no value at all.
 func (f *FlagBase[T, C, V]) GetValue() string {
-	if reflect.TypeOf(f.Value).Kind() == reflect.Bool {
+	if !f.TakesValue() {
 		return ""
 	}
 	return fmt.Sprintf("%v", f.Value)

flag_test.go

@@ -3127,3 +3127,9 @@ func TestEnvHintWindows(t *testing.T) {
 		assert.Equal(t, "something [%foo%, %bar%, %ss%]", withEnvHint([]string{"foo", "bar", "ss"}, "something"))
 	}
 }
+
+func TestDocGetValue(t *testing.T) {
+	assert.Equal(t, "", (&BoolFlag{Name: "foo", Value: true}).GetValue())
+	assert.Equal(t, "", (&BoolFlag{Name: "foo", Value: false}).GetValue())
+	assert.Equal(t, "bar", (&StringFlag{Name: "foo", Value: "bar"}).GetValue())
+}