improve update functionality

* add UpdateAnnotation test
* add PatchAnnotation method

Author: mdb

annotation.go

@@ -124,36 +124,68 @@ func (c *Client) NewGraphiteAnnotation(gfa *GraphiteAnnotation) (int64, error) {
 	return result.ID, err
 }
 
-// UpdateAnnotation updates an existing annotation with the Annotation it is passed
-func (c *Client) UpdateAnnotation(a *Annotation) (int64, error) {
-	path := fmt.Sprintf("/api/annotations/%d", a.ID)
+// UpdateAnnotation updates all properties an existing annotation with the Annotation it is passed.
+func (c *Client) UpdateAnnotation(id int64, a *Annotation) (string, error) {
+	path := fmt.Sprintf("/api/annotations/%d", id)
 	data, err := json.Marshal(a)
 	if err != nil {
-		return 0, err
+		return "", err
 	}
 	req, err := c.newRequest("PUT", path, nil, bytes.NewBuffer(data))
 	if err != nil {
-		return 0, err
+		return "", err
 	}
 
 	resp, err := c.Do(req)
 	if err != nil {
-		return 0, err
+		return "", err
 	}
 	if resp.StatusCode != 200 {
-		return 0, errors.New(resp.Status)
+		return "", errors.New(resp.Status)
 	}
 
 	data, err = ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return 0, err
+		return "", err
 	}
 
 	result := struct {
-		ID int64 `json:"id"`
+		Message string `json:"message"`
 	}{}
 	err = json.Unmarshal(data, &result)
-	return result.ID, err
+	return result.Message, err
+}
+
+// PatchAnnotation updates one or more properties of an existing annotation that matches the specified ID.
+func (c *Client) PatchAnnotation(id int64, a *Annotation) (string, error) {
+	path := fmt.Sprintf("/api/annotations/%d", id)
+	data, err := json.Marshal(a)
+	if err != nil {
+		return "", err
+	}
+	req, err := c.newRequest("PATCH", path, nil, bytes.NewBuffer(data))
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := c.Do(req)
+	if err != nil {
+		return "", err
+	}
+	if resp.StatusCode != 200 {
+		return "", errors.New(resp.Status)
+	}
+
+	data, err = ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	result := struct {
+		Message string `json:"message"`
+	}{}
+	err = json.Unmarshal(data, &result)
+	return result.Message, err
 }
 
 // DeleteAnnotation deletes the annotation of the ID it is passed

annotation_test.go

@@ -40,6 +40,10 @@ const (
 		"id": 1
 	}`
 
+	updateAnnotationJSON = `{"message":"Annotation updated"}`
+
+	patchAnnotationJSON = `{"message":"Annotation patched"}`
+
 	deleteAnnotationJSON = `{"message":"Annotation deleted"}`
 )
 
@@ -89,6 +93,44 @@ func TestNewAnnotation(t *testing.T) {
 	}
 }
 
+func TestUpdateAnnotation(t *testing.T) {
+	server, client := gapiTestTools(200, updateAnnotationJSON)
+	defer server.Close()
+
+	a := Annotation{
+		Text: "new text description",
+	}
+	res, err := client.UpdateAnnotation(1, &a)
+	if err != nil {
+		t.Error(err)
+	}
+
+	t.Log(pretty.PrettyFormat(res))
+
+	if res != "Annotation updated" {
+		t.Error("update annotation response should contain the correct response message")
+	}
+}
+
+func TestPatchAnnotation(t *testing.T) {
+	server, client := gapiTestTools(200, patchAnnotationJSON)
+	defer server.Close()
+
+	a := Annotation{
+		Text: "new text description",
+	}
+	res, err := client.PatchAnnotation(1, &a)
+	if err != nil {
+		t.Error(err)
+	}
+
+	t.Log(pretty.PrettyFormat(res))
+
+	if res != "Annotation patched" {
+		t.Error("patch annotation response should contain the correct response message")
+	}
+}
+
 func TestNewGraphiteAnnotation(t *testing.T) {
 	server, client := gapiTestTools(200, newGraphiteAnnotationJSON)
 	defer server.Close()