Add tests

.travis.yml

@@ -22,4 +22,4 @@ before_script:
   - make vendor_install vendor_sync
 
 script:
-  - make lint build
+  - make lint build test

README.md

@@ -196,7 +196,6 @@ listen test-pod-balancer
 ### TODO
 * Track Kubernetes changes using resource watch API
 * More API and helper template functions
-* Add tests
 
 ## Contributing
 

app_test.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestAppRunOnce(t *testing.T) {
+	cmd := newCmd()
+	buf := new(bytes.Buffer)
+	cmd.SetOutput(buf)
+	testgolden := testGoldenFileName(t)
+	var testout string
+	if *update {
+		testout = testgolden
+	} else {
+		testoutfile, err := ioutil.TempFile("", "testout")
+		require.NoError(t, err)
+		testout = testoutfile.Name()
+		defer testFileUnlink(testout)
+	}
+	err := cmd.ParseFlags([]string{
+		"--once",
+		fmt.Sprintf("--template=%s:%s", testTemplateName(t), testout),
+	})
+	require.NoError(t, err)
+	cfg, err := newConfig(cmd)
+	require.NoError(t, err)
+	app, err := newApp(cfg)
+	require.NoError(t, err)
+	tc := newTestClient()
+	app.client = tc
+	app.dm.client = tc
+	app.RunOnce()
+	actual, err := ioutil.ReadFile(testout)
+	require.NoError(t, err)
+	expected, err := ioutil.ReadFile(testgolden)
+	require.NoError(t, err)
+	require.Equal(t, string(expected), string(actual))
+}

client.go

@@ -33,7 +33,7 @@ const (
 )
 
 type Client struct {
-	kubeClient *kubernetes.Clientset
+	kubeClient kubernetes.Interface
 }
 
 func newClient(cfg *Config) (*Client, error) {

client_test.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/kubernetes/fake"
+	"k8s.io/kubernetes/pkg/controller/testutil"
+
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func newTestClient() *Client {
+	client := Client{}
+	objects := []runtime.Object{
+		&v1.PodList{Items: []v1.Pod{*testutil.NewPod("pod1", "host1")}},
+	}
+	client.kubeClient = fake.NewSimpleClientset(objects...)
+	return &client
+}
+
+func TestClientGetPods(t *testing.T) {
+	tc := newTestClient()
+	pods, err := tc.Pods("", "")
+	require.NoError(t, err)
+	require.Len(t, pods, 1)
+	require.Equal(t, "pod1", pods[0].Name)
+	require.Equal(t, "host1", pods[0].Spec.NodeName)
+}