pkg: move to more generic StringsFlag

pkg/flags/proxy.go

@@ -1,55 +0,0 @@
-/*
-   Copyright 2014 CoreOS, Inc.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-package flags
-
-import (
-	"errors"
-)
-
-const (
-	ProxyValueOff      = "off"
-	ProxyValueReadonly = "readonly"
-	ProxyValueOn       = "on"
-)
-
-var (
-	ProxyValues = []string{
-		ProxyValueOff,
-		ProxyValueReadonly,
-		ProxyValueOn,
-	}
-)
-
-// ProxyFlag implements the flag.Value interface.
-type Proxy string
-
-// Set verifies the argument to be a valid member of proxyFlagValues
-// before setting the underlying flag value.
-func (pf *Proxy) Set(s string) error {
-	for _, v := range ProxyValues {
-		if s == v {
-			*pf = Proxy(s)
-			return nil
-		}
-	}
-
-	return errors.New("invalid value")
-}
-
-func (pf *Proxy) String() string {
-	return string(*pf)
-}

pkg/flags/strings.go

@@ -16,38 +16,33 @@
 
 package flags
 
-import (
-	"errors"
-)
+import "errors"
 
-const (
-	FallbackExit  = "exit"
-	FallbackProxy = "proxy"
-)
+// NewStringsFlag creates a new string flag for which any one of the given
+// strings is a valid value, and any other value is an error.
+func NewStringsFlag(valids ...string) *StringsFlag {
+	return &StringsFlag{Values: valids}
+}
 
-var (
-	FallbackValues = []string{
-		FallbackExit,
-		FallbackProxy,
-	}
-)
+// StringsFlag implements the flag.Value interface.
+type StringsFlag struct {
+	Values []string
+	val    string
+}
 
-// FallbackFlag implements the flag.Value interface.
-type Fallback string
-
-// Set verifies the argument to be a valid member of FallbackFlagValues
+// Set verifies the argument to be a valid member of the allowed values
 // before setting the underlying flag value.
-func (fb *Fallback) Set(s string) error {
-	for _, v := range FallbackValues {
+func (ss *StringsFlag) Set(s string) error {
+	for _, v := range ss.Values {
 		if s == v {
-			*fb = Fallback(s)
+			ss.val = s
 			return nil
 		}
 	}
-
 	return errors.New("invalid value")
 }
 
-func (fb *Fallback) String() string {
-	return string(*fb)
+// String returns the set value (if any) of the StringsFlag
+func (ss *StringsFlag) String() string {
+	return ss.val
 }

pkg/flags/strings_test.go

@@ -20,23 +20,26 @@ import (
 	"testing"
 )
 
-func TestProxySet(t *testing.T) {
+func TestStringsSet(t *testing.T) {
 	tests := []struct {
+		vals []string
+
 		val  string
 		pass bool
 	}{
 		// known values
-		{"on", true},
-		{"off", true},
+		{[]string{"abc", "def"}, "abc", true},
+		{[]string{"on", "off", "false"}, "on", true},
 
 		// unrecognized values
-		{"foo", false},
-		{"", false},
+		{[]string{"abc", "def"}, "ghi", false},
+		{[]string{"on", "off"}, "", false},
+		{[]string{}, "asdf", false},
 	}
 
 	for i, tt := range tests {
-		pf := new(Proxy)
-		err := pf.Set(tt.val)
+		sf := NewStringsFlag(tt.vals...)
+		err := sf.Set(tt.val)
 		if tt.pass != (err == nil) {
 			t.Errorf("#%d: want pass=%t, but got err=%v", i, tt.pass, err)
 		}