ResourceNames() should prohibit unnamed arguments

pkg/kubectl/resource/builder.go

@@ -212,6 +212,10 @@ func (b *Builder) ResourceNames(resource string, names ...string) *Builder {
 			b.resourceTuples = append(b.resourceTuples, tuple)
 			continue
 		}
+		if len(resource) == 0 {
+			b.errs = append(b.errs, fmt.Errorf("the argument %q must be RESOURCE/NAME", name))
+			continue
+		}
 
 		// Use the given default type to create a resource tuple
 		b.resourceTuples = append(b.resourceTuples, resourceTuple{Resource: resource, Name: name})

pkg/kubectl/resource/builder_test.go

@@ -626,6 +626,28 @@ func TestResourceNames(t *testing.T) {
 	}
 }
 
+func TestResourceNamesWithoutResource(t *testing.T) {
+	pods, svc := testData()
+	b := NewBuilder(testapi.Default.RESTMapper(), api.Scheme, fakeClientWith("", t, map[string]string{
+		"/namespaces/test/pods/foo":     runtime.EncodeOrDie(testapi.Default.Codec(), &pods.Items[0]),
+		"/namespaces/test/services/baz": runtime.EncodeOrDie(testapi.Default.Codec(), &svc.Items[0]),
+	}), testapi.Default.Codec()).
+		NamespaceParam("test")
+
+	test := &testVisitor{}
+
+	if b.Do().Err() == nil {
+		t.Errorf("unexpected non-error")
+	}
+
+	b.ResourceNames("", "foo", "services/baz")
+
+	err := b.Do().Visit(test.Handle)
+	if err == nil || !strings.Contains(err.Error(), "must be RESOURCE/NAME") {
+		t.Fatalf("unexpected response: %v", err)
+	}
+}
+
 func TestResourceByNameWithoutRequireObject(t *testing.T) {
 	b := NewBuilder(testapi.Default.RESTMapper(), api.Scheme, fakeClientWith("", t, map[string]string{}), testapi.Default.Codec()).
 		NamespaceParam("test")