diff --git a/cmd/kubectx/delete.go b/cmd/kubectx/delete.go
index fe0277d..ade6f95 100644
--- a/cmd/kubectx/delete.go
+++ b/cmd/kubectx/delete.go
@@ -23,7 +23,7 @@ func (op DeleteOp) Run(_, stderr io.Writer) error {
 		}
 		if wasActiveContext {
 			// TODO we don't always run as kubectx (sometimes "kubectl ctx")
-			printWarning(stderr,"You deleted the current context. use \"kubectx\" to select a different one.")
+			printWarning(stderr, "You deleted the current context. use \"kubectx\" to select a different one.")
 		}
 
 		printSuccess(stderr, "deleted context %q", deletedName)
@@ -57,4 +57,3 @@ func deleteContext(name string) (deleteName string, wasActiveContext bool, err e
 	}
 	return name, wasActiveContext, errors.Wrap(kc.Save(), "failed to save kubeconfig file")
 }
-
diff --git a/cmd/kubectx/env.go b/cmd/kubectx/env.go
new file mode 100644
index 0000000..0bbcda9
--- /dev/null
+++ b/cmd/kubectx/env.go
@@ -0,0 +1,26 @@
+package main
+
+import "os"
+
+const (
+	// EnvFZFIgnore describes the environment variable to set to disable
+	// interactive context selection when fzf is installed.
+	EnvFZFIgnore = "KUBECTX_IGNORE_FZF"
+
+	// EnvForceColor describes the environment variable to disable color usage
+	// when printing current context in a list.
+	EnvNoColor = `NO_COLOR`
+
+	// EnvForceColor describes the "internal" environment variable to force
+	// color usage to show current context in a list.
+	EnvForceColor = `_KUBECTX_FORCE_COLOR`
+)
+
+func useColors() bool {
+	if os.Getenv(EnvForceColor) != "" {
+		return true
+	} else if os.Getenv(EnvNoColor) != "" {
+		return false
+	}
+	return true
+}
diff --git a/cmd/kubectx/env_test.go b/cmd/kubectx/env_test.go
new file mode 100644
index 0000000..5bac28e
--- /dev/null
+++ b/cmd/kubectx/env_test.go
@@ -0,0 +1,44 @@
+package main
+
+import (
+	"os"
+	"testing"
+)
+
+func withTestVar(key, value string) func() {
+	orig, ok := os.LookupEnv(key)
+	os.Setenv(key, value)
+	return func() {
+		if ok {
+			os.Setenv(key, orig)
+		} else {
+			os.Unsetenv(key)
+		}
+	}
+}
+
+func Test_useColors_forceColors(t *testing.T) {
+	defer withTestVar("_KUBECTX_FORCE_COLOR", "1")()
+	defer withTestVar("NO_COLOR", "1")()
+
+	if !useColors() {
+		t.Fatal("expected useColors() = true")
+	}
+}
+
+func Test_useColors_disableColors(t *testing.T) {
+	defer withTestVar("NO_COLOR", "1")()
+
+	if useColors() {
+		t.Fatal("expected useColors() = false")
+	}
+}
+
+func Test_useColors_default(t *testing.T) {
+	defer withTestVar("NO_COLOR", "")()
+	defer withTestVar("_KUBECTX_FORCE_COLOR", "")()
+
+	if !useColors() {
+		t.Fatal("expected useColors() = true")
+	}
+}
diff --git a/cmd/kubectx/flags.go b/cmd/kubectx/flags.go
index bc5a2aa..11603c9 100644
--- a/cmd/kubectx/flags.go
+++ b/cmd/kubectx/flags.go
@@ -23,7 +23,7 @@ func (op UnsupportedOp) Run(_, _ io.Writer) error {
 // and decides which operation should be taken.
 func parseArgs(argv []string) Op {
 	if len(argv) == 0 {
-		if isInteractiveMode(os.Stdout){
+		if isInteractiveMode(os.Stdout) {
 			return InteractiveSwitchOp{SelfCmd: os.Args[0]}
 		}
 		return ListOp{}
diff --git a/cmd/kubectx/flags_test.go b/cmd/kubectx/flags_test.go
index 3ca5477..6c6128c 100644
--- a/cmd/kubectx/flags_test.go
+++ b/cmd/kubectx/flags_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/pkg/errors"
 )
 
 func Test_parseArgs_new(t *testing.T) {
@@ -59,7 +60,7 @@ func Test_parseArgs_new(t *testing.T) {
 			want: RenameOp{"a", "."}},
 		{name: "unrecognized flag",
 			args: []string{"-x"},
-			want: UnsupportedOp{Args: []string{"-x"}}},
+			want: UnsupportedOp{Err: errors.Errorf("unsupported option \"-x\"")}},
 		// TODO add more UnsupportedOp cases
 
 		// TODO consider these cases
diff --git a/cmd/kubectx/fzf.go b/cmd/kubectx/fzf.go
index c02f241..4d466f8 100644
--- a/cmd/kubectx/fzf.go
+++ b/cmd/kubectx/fzf.go
@@ -13,10 +13,6 @@ import (
 	"github.com/mattn/go-isatty"
 )
 
-const (
-	envFZFIgnore = "KUBECTX_IGNORE_FZF"
-)
-
 type InteractiveSwitchOp struct {
 	SelfCmd string
 }
@@ -30,7 +26,7 @@ func (op InteractiveSwitchOp) Run(_, stderr io.Writer) error {
 
 	cmd.Env = append(os.Environ(),
 		fmt.Sprintf("FZF_DEFAULT_COMMAND=%s", op.SelfCmd),
-		fmt.Sprintf("%s=1", envForceColor))
+		fmt.Sprintf("%s=1", EnvForceColor))
 	if err := cmd.Run(); err != nil {
 		if _, ok := err.(*exec.ExitError); !ok {
 			return err
@@ -64,6 +60,6 @@ func fzfInstalled() bool {
 
 // isInteractiveMode determines if we can do choosing with fzf.
 func isInteractiveMode(stdout *os.File) bool {
-	v := os.Getenv(envFZFIgnore)
+	v := os.Getenv(EnvFZFIgnore)
 	return v == "" && isTerminal(stdout) && fzfInstalled()
 }
diff --git a/cmd/kubectx/help_test.go b/cmd/kubectx/help_test.go
index b8702e7..544939a 100644
--- a/cmd/kubectx/help_test.go
+++ b/cmd/kubectx/help_test.go
@@ -8,7 +8,9 @@ import (
 
 func TestPrintHelp(t *testing.T) {
 	var buf bytes.Buffer
-	printHelp(&buf)
+	if err := (&HelpOp{}).Run(&buf, &buf); err != nil {
+		t.Fatal(err)
+	}
 
 	out := buf.String()
 	if !strings.Contains(out, "USAGE:") {
diff --git a/cmd/kubectx/kubeconfig.go b/cmd/kubectx/kubeconfig.go
index 91ce5e4..dcca8a3 100644
--- a/cmd/kubectx/kubeconfig.go
+++ b/cmd/kubectx/kubeconfig.go
@@ -15,13 +15,13 @@ var (
 
 type StandardKubeconfigLoader struct{}
 
-type kubeconfigFile struct { *os.File }
+type kubeconfigFile struct{ *os.File }
 
 func (kf *kubeconfigFile) Reset() error {
-	if err := kf.Truncate(0);err!= nil {
+	if err := kf.Truncate(0); err != nil {
 		return errors.Wrap(err, "failed to truncate file")
 	}
-	_, err := kf.Seek(0,0)
+	_, err := kf.Seek(0, 0)
 	return errors.Wrap(err, "failed to seek in file")
 }
 
diff --git a/cmd/kubectx/kubeconfig/contextmodify_test.go b/cmd/kubectx/kubeconfig/contextmodify_test.go
index 1449df4..812b024 100644
--- a/cmd/kubectx/kubeconfig/contextmodify_test.go
+++ b/cmd/kubectx/kubeconfig/contextmodify_test.go
@@ -46,7 +46,7 @@ func TestKubeconfig_DeleteContextEntry(t *testing.T) {
 
 	expected := "contexts: [{name: c2}, {name: c3}]\n"
 	out := test.out.String()
-	if diff := cmp.Diff(expected,out); diff != "" {
+	if diff := cmp.Diff(expected, out); diff != "" {
 		t.Fatalf("diff: %s", diff)
 	}
 }
@@ -67,9 +67,9 @@ field1: value1`)}
 	}
 
 	expected := `current-context: foo
-field1: value1`+"\n"
+field1: value1` + "\n"
 	out := test.out.String()
-	if diff := cmp.Diff(expected,out); diff != "" {
+	if diff := cmp.Diff(expected, out); diff != "" {
 		t.Fatalf("diff: %s", diff)
 	}
 }
@@ -90,7 +90,7 @@ func TestKubeconfig_ModifyCurrentContext_fieldMissing(t *testing.T) {
 
 	expected := `field1: value1` + "\n" + "current-context: foo\n"
 	out := test.out.String()
-	if diff := cmp.Diff(expected,out); diff != "" {
+	if diff := cmp.Diff(expected, out); diff != "" {
 		t.Fatalf("diff: %s", diff)
 	}
 }
@@ -123,7 +123,7 @@ func TestKubeconfig_ModifyContextName(t *testing.T) {
 
 	expected := "contexts: [{name: ccc}, {name: c2}, {name: c3}]\n"
 	out := test.out.String()
-	if diff := cmp.Diff(expected,out); diff != "" {
+	if diff := cmp.Diff(expected, out); diff != "" {
 		t.Fatalf("diff: %s", diff)
 	}
 }
diff --git a/cmd/kubectx/kubeconfig/currentcontext.go b/cmd/kubectx/kubeconfig/currentcontext.go
index 7225591..131851e 100644
--- a/cmd/kubectx/kubeconfig/currentcontext.go
+++ b/cmd/kubectx/kubeconfig/currentcontext.go
@@ -2,7 +2,7 @@ package kubeconfig
 
 // GetCurrentContext returns "current-context" value in given
 // kubeconfig object Node, or returns "" if not found.
-func  (k *Kubeconfig) GetCurrentContext() string {
+func (k *Kubeconfig) GetCurrentContext() string {
 	v := valueOf(k.rootNode, "current-context")
 	if v == nil {
 		return ""
diff --git a/cmd/kubectx/kubeconfig/kubeconfig.go b/cmd/kubectx/kubeconfig/kubeconfig.go
index 0f5ff06..098e400 100644
--- a/cmd/kubectx/kubeconfig/kubeconfig.go
+++ b/cmd/kubectx/kubeconfig/kubeconfig.go
@@ -7,7 +7,7 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
-type ReadWriteResetCloser interface{
+type ReadWriteResetCloser interface {
 	io.ReadWriteCloser
 
 	// Reset truncates the file and seeks to the beginning of the file.
@@ -19,9 +19,9 @@ type Loader interface {
 }
 
 type Kubeconfig struct {
-	loader   Loader
+	loader Loader
 
-	f ReadWriteResetCloser
+	f        ReadWriteResetCloser
 	rootNode *yaml.Node
 }
 
diff --git a/cmd/kubectx/kubeconfig_test.go b/cmd/kubectx/kubeconfig_test.go
index a1ff3fa..ea7bf2c 100644
--- a/cmd/kubectx/kubeconfig_test.go
+++ b/cmd/kubectx/kubeconfig_test.go
@@ -19,7 +19,7 @@ func Test_kubeconfigPath_homePath(t *testing.T) {
 	}
 	expected := filepath.Join(filepath.FromSlash("/foo/bar"), ".kube", "config")
 
-	if got != expected{
+	if got != expected {
 		t.Fatalf("wrong value: expected=%s got=%s", expected, got)
 	}
 }
@@ -36,7 +36,7 @@ func Test_kubeconfigPath_userprofile(t *testing.T) {
 	}
 	expected := filepath.Join(filepath.FromSlash("/foo/bar"), ".kube", "config")
 
-	if got != expected{
+	if got != expected {
 		t.Fatalf("wrong value: expected=%s got=%s", expected, got)
 	}
 }
@@ -60,19 +60,23 @@ func Test_kubeconfigPath_envOvveride(t *testing.T) {
 	defer os.Unsetenv("KUBECONFIG")
 
 	v, err := kubeconfigPath()
-	if err != nil { t.Fatal(err)}
+	if err != nil {
+		t.Fatal(err)
+	}
 	if expected := "foo"; v != expected {
 		t.Fatalf("expected=%q, got=%q", expected, v)
 	}
 }
 
 func Test_kubeconfigPath_envOvverideDoesNotSupportPathSeparator(t *testing.T) {
-	path := strings.Join([]string{"file1","file2"}, string(os.PathListSeparator))
+	path := strings.Join([]string{"file1", "file2"}, string(os.PathListSeparator))
 	os.Setenv("KUBECONFIG", path)
 	defer os.Unsetenv("KUBECONFIG")
 
 	_, err := kubeconfigPath()
-	if err == nil { t.Fatal("expected error")}
+	if err == nil {
+		t.Fatal("expected error")
+	}
 }
 
 func testfile(t *testing.T, contents string) (path string, cleanup func()) {
diff --git a/cmd/kubectx/list.go b/cmd/kubectx/list.go
index 1ed785b..6e0d46f 100644
--- a/cmd/kubectx/list.go
+++ b/cmd/kubectx/list.go
@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"io"
-	"os"
 
 	"facette.io/natsort"
 	"github.com/fatih/color"
@@ -29,13 +28,13 @@ func (_ ListOp) Run(stdout, _ io.Writer) error {
 	// TODO support KUBECTX_CURRENT_BGCOLOR
 
 	currentColor := color.New(color.FgGreen, color.Bold)
-	if useColors(){
+	if useColors() {
 		currentColor.EnableColor()
 	} else {
 		currentColor.DisableColor()
 	}
 
-	cur :=  kc.GetCurrentContext()
+	cur := kc.GetCurrentContext()
 	for _, c := range ctxs {
 		s := c
 		if c == cur {
@@ -45,17 +44,3 @@ func (_ ListOp) Run(stdout, _ io.Writer) error {
 	}
 	return nil
 }
-
-const (
-	envForceColor = `_KUBECTX_FORCE_COLOR`
-	envNoColor = `NO_COLOR`
-)
-
-func useColors() bool {
-	if os.Getenv(envForceColor) != "" {
-		return true
-	} else if os.Getenv(envNoColor) != "" {
-		return false
-	}
-	return true
-}
diff --git a/cmd/kubectx/main.go b/cmd/kubectx/main.go
index fed54e4..45767fd 100644
--- a/cmd/kubectx/main.go
+++ b/cmd/kubectx/main.go
@@ -30,4 +30,3 @@ func printWarning(w io.Writer, format string, args ...interface{}) {
 func printSuccess(w io.Writer, format string, args ...interface{}) {
 	fmt.Fprintf(w, color.GreenString(fmt.Sprintf(format+"\n", args...)))
 }
-
diff --git a/cmd/kubectx/rename.go b/cmd/kubectx/rename.go
index 3f9ca82..680f362 100644
--- a/cmd/kubectx/rename.go
+++ b/cmd/kubectx/rename.go
@@ -48,7 +48,7 @@ func (op RenameOp) Run(_, stderr io.Writer) error {
 		return errors.Errorf("context %q not found, can't rename it", op.Old)
 	}
 
-	if kc.ContextExists( op.New) {
+	if kc.ContextExists(op.New) {
 		printWarning(stderr, "context %q exists, overwriting it.", op.New)
 		if err := kc.DeleteContextEntry(op.New); err != nil {
 			return errors.Wrap(err, "failed to delete new context to overwrite it")
@@ -59,7 +59,7 @@ func (op RenameOp) Run(_, stderr io.Writer) error {
 		return errors.Wrap(err, "failed to change context name")
 	}
 	if op.New == cur {
-		if err := kc.ModifyCurrentContext( op.New); err != nil {
+		if err := kc.ModifyCurrentContext(op.New); err != nil {
 			return errors.Wrap(err, "failed to set current-context to new name")
 		}
 	}
@@ -69,4 +69,3 @@ func (op RenameOp) Run(_, stderr io.Writer) error {
 	printSuccess(stderr, "Context %q renamed to %q.", op.Old, op.New)
 	return nil
 }
-
diff --git a/cmd/kubectx/switch.go b/cmd/kubectx/switch.go
index ef78ceb..945f8db 100644
--- a/cmd/kubectx/switch.go
+++ b/cmd/kubectx/switch.go
@@ -60,7 +60,6 @@ func switchContext(name string) (string, error) {
 	return name, nil
 }
 
-
 // swapContext switches to previously switch context.
 func swapContext() (string, error) {
 	prevCtxFile, err := kubectxPrevCtxFile()
diff --git a/cmd/kubectx/unset.go b/cmd/kubectx/unset.go
index 816bb40..a3c4377 100644
--- a/cmd/kubectx/unset.go
+++ b/cmd/kubectx/unset.go
@@ -29,4 +29,3 @@ func (_ UnsetOp) Run(_, stderr io.Writer) error {
 	_, err := fmt.Fprintln(stderr, "Successfully unset the current context")
 	return err
 }
-