Add message when no contexts are found in kubeconfig

cmd/kubectx/fzf.go

@@ -23,13 +23,20 @@ type InteractiveSwitchOp struct {
 func (op InteractiveSwitchOp) Run(_, stderr io.Writer) error {
 	// parse kubeconfig just to see if it can be loaded
 	kc := new(kubeconfig.Kubeconfig).WithLoader(kubeconfig.DefaultLoader)
+
 	if err := kc.Parse(); err != nil {
 		if cmdutil.IsNotFoundErr(err) {
 			printer.Warning(stderr, "kubeconfig file not found")
 			return nil
 		}
 		return errors.Wrap(err, "kubeconfig error")
 	}
+
+	ctxs := kc.ContextNames()
+	if ctxs == nil {
+		err := printer.Warning(stderr, "No kubectl context found")
+		return errors.Wrap(err, "kubeconfig error")
+	}
 	kc.Close()
 
 	cmd := exec.Command("fzf", "--ansi", "--no-preview")

cmd/kubectx/list.go

@@ -27,6 +27,10 @@ func (_ ListOp) Run(stdout, stderr io.Writer) error {
 	}
 
 	ctxs := kc.ContextNames()
+	if ctxs == nil {
+		err := printer.Warning(stderr, "No kubectl context found")
+		return errors.Wrap(err, "kubeconfig error")
+	}
 	natsort.Sort(ctxs)
 
 	cur := kc.GetCurrentContext()

test/kubectx.bats

@@ -214,7 +214,7 @@ load common
   run ${COMMAND}
   echo "$output"
   [ "$status" -eq 0 ]
-  [[ "$output" = "" ]]
+  [[ "$output" = "warning: No kubectl context found" ]]
 }
 
 @test "delete several contexts including a non existent one" {
@@ -242,3 +242,11 @@ load common
   run ${COMMAND} -c
   [ "$status" -ne 0 ]
 }
+
+@test "display msg on empty context" {
+  use_config config3
+  run ${COMMAND}
+  echo "$output"
+  [ "$status" -eq 0 ]
+  [[ "$output" = "warning: No kubectl context found" ]]
+}

test/testdata/config3

@@ -0,0 +1,15 @@
+# config with no context
+
+apiVersion: v1
+clusters:
+- cluster:
+    server: ""
+  name: cluster1
+contexts:
+- context:
+current-context: ""
+kind: Config
+preferences: {}
+users:
+- name: user1
+  user: {}