diff --git a/pkg/edit/BUILD.bazel b/pkg/edit/BUILD.bazel
index 7a9efbc74d..7816a162d4 100644
--- a/pkg/edit/BUILD.bazel
+++ b/pkg/edit/BUILD.bazel
@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -12,3 +12,15 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
     ],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["edit_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//pkg/apis/kops/v1alpha2:go_default_library",
+        "//vendor/github.com/MakeNowJust/heredoc:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
+    ],
+)
diff --git a/pkg/edit/edit_test.go b/pkg/edit/edit_test.go
new file mode 100644
index 0000000000..d69bfa8abb
--- /dev/null
+++ b/pkg/edit/edit_test.go
@@ -0,0 +1,91 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package edit
+
+import (
+	"testing"
+	"time"
+
+	"github.com/MakeNowJust/heredoc"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/kops/pkg/apis/kops/v1alpha2"
+)
+
+var testTimestamp = metav1.Time{Time: time.Date(2017, 1, 1, 0, 0, 0, 0, time.UTC)}
+var testObj = v1alpha2.Cluster{
+	ObjectMeta: metav1.ObjectMeta{
+		CreationTimestamp: testTimestamp,
+		Name:              "hello",
+	},
+	Spec: v1alpha2.ClusterSpec{
+		KubernetesVersion: "1.2.3",
+	},
+}
+
+func TestHasExtraFields(t *testing.T) {
+	tests := []struct {
+		obj      runtime.Object
+		yaml     string
+		expected string
+	}{
+		{
+			obj: &testObj,
+			yaml: heredoc.Doc(`
+			apiVersion: kops.k8s.io/v1alpha2
+			kind: Cluster
+			metadata:
+			  creationTimestamp: "2017-01-01T00:00:00Z"
+			  name: hello
+			spec:
+			  kubernetesVersion: 1.2.3
+			`),
+			expected: "",
+		},
+		{
+			obj: &testObj,
+			yaml: heredoc.Doc(`
+			apiVersion: kops.k8s.io/v1alpha2
+			kind: Cluster
+			metadata:
+			  creationTimestamp: "2017-01-01T00:00:00Z"
+			  name: hello
+			spec2:
+			  kubernetesVersion: 1.2.3
+			`),
+			expected: heredoc.Doc(`...
+			    creationTimestamp: "2017-01-01T00:00:00Z"
+			    name: hello
+			+ spec2:
+			- spec:
+			    kubernetesVersion: 1.2.3
+			`),
+		},
+	}
+
+	for _, test := range tests {
+		result, err := HasExtraFields(test.yaml, test.obj)
+		if err != nil {
+			t.Errorf("Error from HasExtraFields: %v", err)
+			continue
+		}
+		if result != test.expected {
+			t.Errorf("Actual result:\n %s \nExpect:\n %s", result, test.expected)
+		}
+	}
+}