add test for empty contexts

test/kubectx.bats

@@ -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: {}