Add object interfaces for better testability (#3)

castai · Aug 2, 2022 · cee0c49 · cee0c49
1 parent 9f09e55
commit cee0c49
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Showing 5 changed files with 60 additions and 45 deletions.
diff --git a/README.md b/README.md
@@ -18,7 +18,8 @@ func main() {
         log.Fatal(err)
     }
     ctx := context.Backgroud()
-    endpoints, err := client.Get[*client.Endpoints](kc, ctx, "/api/v1/namespaces/kube-system/endpoints/kubelet", client.GetOptions{})
+    endpointsOperator := client.NewEndpointsOperator(kc)
+    endpoints, err := endpointsOperator.Get(ctx, "kube-system", "kubelet", client.GetOptions{})
     if err != nil {
         log.Fatal(err)
     }

diff --git a/client.go b/client.go
@@ -34,6 +34,22 @@ type Interface interface {
 	Token() string
 }
 
+// ObjectGetter is generic object getter.
+type ObjectGetter[T Object] interface {
+	Get(ctx context.Context, namespace, name string, _ GetOptions) (T, error)
+}
+
+// ObjectWatcher is generic object watcher.
+type ObjectWatcher[T Object] interface {
+	Watch(ctx context.Context, namespace, name string, _ ListOptions) (WatchInterface[T], error)
+}
+
+// ObjectOperator wraps all operations on object.
+type ObjectOperator[T Object] interface {
+	ObjectGetter[T]
+	ObjectWatcher[T]
+}
+
 // NewInCluster creates Client if it is inside Kubernetes.
 func NewInCluster() (*Client, error) {
 	host, port := os.Getenv("KUBERNETES_SERVICE_HOST"), os.Getenv("KUBERNETES_SERVICE_PORT")
@@ -142,7 +158,7 @@ func (kc *Client) Token() string {
 	return kc.token
 }
 
-func Get[T Object](kc *Client, ctx context.Context, reqURL string, _ GetOptions) (T, error) {
+func get[T Object](kc *Client, ctx context.Context, reqURL string, _ GetOptions) (T, error) {
 	var t T
 	u, err := url.Parse(reqURL)
 	if err != nil {
@@ -167,7 +183,7 @@ func Get[T Object](kc *Client, ctx context.Context, reqURL string, _ GetOptions)
 	return t, err
 }
 
-func Watch[T Object](kc *Client, ctx context.Context, reqURL string, _ ListOptions) (WatchInterface[T], error) {
+func watch[T Object](kc *Client, ctx context.Context, reqURL string, _ ListOptions) (WatchInterface[T], error) {
 	u, err := url.Parse(reqURL)
 	if err != nil {
 		return nil, err
@@ -188,29 +204,3 @@ func Watch[T Object](kc *Client, ctx context.Context, reqURL string, _ ListOptio
 
 	return newStreamWatcher[T](resp.Body, kc.Logger, kc.ResponseDecoderFunc(resp.Body)), nil
 }
-
-func GetEndpoints(kc *Client, ctx context.Context, namespace, name string, opts GetOptions) (*Endpoints, error) {
-	reqURL := fmt.Sprintf("%s/api/v1/namespaces/%s/endpoints/%s", kc.Host, namespace, name)
-	return Get[*Endpoints](kc, ctx, reqURL, opts)
-}
-
-func WatchEndpoints(kc *Client, ctx context.Context, namespace, name string, _ ListOptions) (WatchInterface[*Endpoints], error) {
-	u, err := url.Parse(fmt.Sprintf("%s/api/v1/watch/namespaces/%s/endpoints/%s", kc.Host, namespace, name))
-	if err != nil {
-		return nil, err
-	}
-	req, err := kc.GetRequest(ctx, u.String())
-	if err != nil {
-		return nil, err
-	}
-	resp, err := kc.Do(req)
-	if err != nil {
-		return nil, err
-	}
-	if resp.StatusCode != http.StatusOK {
-		defer resp.Body.Close()
-		errmsg, _ := ioutil.ReadAll(resp.Body)
-		return nil, fmt.Errorf("invalid response code %d for service %s in namespace %s: %s", resp.StatusCode, name, namespace, string(errmsg))
-	}
-	return newStreamWatcher[*Endpoints](resp.Body, kc.Logger, kc.ResponseDecoderFunc(resp.Body)), nil
-}
diff --git a/client_test.go b/client_test.go
@@ -16,28 +16,22 @@ func ExampleClient() {
 
 	ctx := context.Background()
 
-	// Generic get.
-	endpoints, err := client.Get[*client.Endpoints](kc, ctx, "/api/v1/namespaces/kube-system/endpoints/kubelet", client.GetOptions{})
+	// Getter example.
+	endpointsOperator := client.NewEndpointsOperator(kc)
+	endpoints, err := endpointsOperator.Get(ctx, "kube-system", "kubelet", client.GetOptions{})
 	if err != nil {
 		// Handle err
 		return
 	}
+	fmt.Printf("%+v\n", endpoints)
 
-	// Typed methods. Simple wrapper for Get.
-	endpoints, err = client.GetEndpoints(kc, ctx, "kube-system", "kubelet", client.GetOptions{})
+	// Watcher example.
+	events, err := endpointsOperator.Watch(ctx, "kube-system", "kubelet", client.ListOptions{})
 	if err != nil {
 		// Handle err
 		return
 	}
-	fmt.Printf("%+v", endpoints)
-
-	// Watch support.
-	events, err := client.Watch[*client.Endpoints](kc, ctx, "/api/v1/namespaces/kube-system/endpoints/kubelet", client.ListOptions{})
-	if err != nil {
-		// Handle err
-		return
-	}
-	for event := range events.ResultChan() {
-		fmt.Println(event.Type, event.Object)
+	for e := range events.ResultChan() {
+		fmt.Printf("%s: %+v\n", e.Type, e.Object)
 	}
 }
diff --git a/e2e/main.go b/e2e/main.go
@@ -47,12 +47,14 @@ func testEndpoints(nativeClient *kubernetes.Clientset, kc *client.Client) error
 		return fmt.Errorf("creating test endpoint: %w", err)
 	}
 
+	endpointsOperator := client.NewEndpointsOperator(kc)
+
 	a, err := nativeClient.CoreV1().Endpoints(testEndpoints.Namespace).Get(context.Background(), testEndpoints.Name, metav1.GetOptions{})
 	if err != nil {
 		return fmt.Errorf("getting endpoint using native client: %w", err)
 	}
 
-	b, err := client.GetEndpoints(kc, context.Background(), testEndpoints.Namespace, testEndpoints.Name, client.GetOptions{})
+	b, err := endpointsOperator.Get(context.Background(), testEndpoints.Namespace, testEndpoints.Name, client.GetOptions{})
 	if err != nil {
 		return fmt.Errorf("getting endpoint using client: %w", err)
 	}
@@ -103,7 +105,7 @@ func testEndpoints(nativeClient *kubernetes.Clientset, kc *client.Client) error
 	})
 
 	errg.Go(func() error {
-		e, err := client.WatchEndpoints(kc, context.Background(), testEndpoints.Namespace, testEndpoints.Name, client.ListOptions{})
+		e, err := endpointsOperator.Watch(context.Background(), testEndpoints.Namespace, testEndpoints.Name, client.ListOptions{})
 		if err != nil {
 			return fmt.Errorf("watching using native client: %w", err)
 		}

diff --git a/endpoints.go b/endpoints.go
@@ -0,0 +1,28 @@
+package client
+
+import (
+	"context"
+	"fmt"
+)
+
+var _ ObjectOperator[*Endpoints] = (*EndpointsOperator)(nil)
+
+func NewEndpointsOperator(kc *Client) *EndpointsOperator {
+	return &EndpointsOperator{
+		kc: kc,
+	}
+}
+
+type EndpointsOperator struct {
+	kc *Client
+}
+
+func (e *EndpointsOperator) Get(ctx context.Context, namespace, name string, opts GetOptions) (*Endpoints, error) {
+	reqURL := fmt.Sprintf("%s/api/v1/namespaces/%s/endpoints/%s", e.kc.Host, namespace, name)
+	return get[*Endpoints](e.kc, ctx, reqURL, opts)
+}
+
+func (e *EndpointsOperator) Watch(ctx context.Context, namespace, name string, opts ListOptions) (WatchInterface[*Endpoints], error) {
+	reqURL := fmt.Sprintf("%s/api/v1/watch/namespaces/%s/endpoints/%s", e.kc.Host, namespace, name)
+	return watch[*Endpoints](e.kc, ctx, reqURL, opts)
+}