Change error variable identifiers to ErrFoo

pkg/kubectl/plugins/plugins.go

@@ -23,11 +23,16 @@ import (
 )
 
 var (
-	IncompletePluginError     = fmt.Errorf("incomplete plugin descriptor: name, shortDesc and command fields are required")
-	InvalidPluginNameError    = fmt.Errorf("plugin name can't contain spaces")
-	IncompleteFlagError       = fmt.Errorf("incomplete flag descriptor: name and desc fields are required")
-	InvalidFlagNameError      = fmt.Errorf("flag name can't contain spaces")
-	InvalidFlagShorthandError = fmt.Errorf("flag shorthand must be only one letter")
+	// ErrIncompletePlugin indicates plugin is incomplete.
+	ErrIncompletePlugin = fmt.Errorf("incomplete plugin descriptor: name, shortDesc and command fields are required")
+	// ErrInvalidPluginName indicates plugin name is invalid.
+	ErrInvalidPluginName = fmt.Errorf("plugin name can't contain spaces")
+	// ErrIncompleteFlag indicates flag is incomplete.
+	ErrIncompleteFlag = fmt.Errorf("incomplete flag descriptor: name and desc fields are required")
+	// ErrInvalidFlagName indicates flag name is invalid.
+	ErrInvalidFlagName = fmt.Errorf("flag name can't contain spaces")
+	// ErrInvalidFlagShorthand indicates flag shorthand is invalid.
+	ErrInvalidFlagShorthand = fmt.Errorf("flag shorthand must be only one letter")
 )
 
 // Plugin is the representation of a CLI extension (plugin).
@@ -58,10 +63,10 @@ type Source struct {
 // Validate validates plugin data.
 func (p Plugin) Validate() error {
 	if len(p.Name) == 0 || len(p.ShortDesc) == 0 || (len(p.Command) == 0 && len(p.Tree) == 0) {
-		return IncompletePluginError
+		return ErrIncompletePlugin
 	}
 	if strings.Index(p.Name, " ") > -1 {
-		return InvalidPluginNameError
+		return ErrInvalidPluginName
 	}
 	for _, flag := range p.Flags {
 		if err := flag.Validate(); err != nil {
@@ -95,10 +100,10 @@ type Flag struct {
 // Validate validates flag data.
 func (f Flag) Validate() error {
 	if len(f.Name) == 0 || len(f.Desc) == 0 {
-		return IncompleteFlagError
+		return ErrIncompleteFlag
 	}
 	if strings.Index(f.Name, " ") > -1 {
-		return InvalidFlagNameError
+		return ErrInvalidFlagName
 	}
 	return f.ValidateShorthand()
 }
@@ -109,7 +114,7 @@ func (f Flag) ValidateShorthand() error {
 	if length == 0 || (length == 1 && unicode.IsLetter(rune(f.Shorthand[0]))) {
 		return nil
 	}
-	return InvalidFlagShorthandError
+	return ErrInvalidFlagShorthand
 }
 
 // Shorthanded returns true if flag shorthand data is valid.

pkg/kubectl/plugins/plugins_test.go

@@ -39,11 +39,11 @@ func TestPlugin(t *testing.T) {
 					ShortDesc: "The test",
 				},
 			},
-			expectedErr: IncompletePluginError,
+			expectedErr: ErrIncompletePlugin,
 		},
 		{
 			plugin:      &Plugin{},
-			expectedErr: IncompletePluginError,
+			expectedErr: ErrIncompletePlugin,
 		},
 		{
 			plugin: &Plugin{
@@ -53,7 +53,7 @@ func TestPlugin(t *testing.T) {
 					Command:   "echo 1",
 				},
 			},
-			expectedErr: InvalidPluginNameError,
+			expectedErr: ErrInvalidPluginName,
 		},
 		{
 			plugin: &Plugin{
@@ -68,7 +68,7 @@ func TestPlugin(t *testing.T) {
 					},
 				},
 			},
-			expectedErr: IncompleteFlagError,
+			expectedErr: ErrIncompleteFlag,
 		},
 		{
 			plugin: &Plugin{
@@ -84,7 +84,7 @@ func TestPlugin(t *testing.T) {
 					},
 				},
 			},
-			expectedErr: InvalidFlagNameError,
+			expectedErr: ErrInvalidFlagName,
 		},
 		{
 			plugin: &Plugin{
@@ -101,7 +101,7 @@ func TestPlugin(t *testing.T) {
 					},
 				},
 			},
-			expectedErr: InvalidFlagShorthandError,
+			expectedErr: ErrInvalidFlagShorthand,
 		},
 		{
 			plugin: &Plugin{
@@ -118,7 +118,7 @@ func TestPlugin(t *testing.T) {
 					},
 				},
 			},
-			expectedErr: InvalidFlagShorthandError,
+			expectedErr: ErrInvalidFlagShorthand,
 		},
 		{
 			plugin: &Plugin{