Return did resolution result from anchor op. (#422)

did/ion/operations_test.go

@@ -133,22 +133,24 @@ func TestResolver(t *testing.T) {
 	t.Run("bad anchor", func(tt *testing.T) {
 		gock.New("https://test-ion-resolution.com").
 			Post("/operations").
-			Reply(400)
+			Reply(400).
+			BodyString("{}")
 		defer gock.Off()
 
 		resolver, err := NewIONResolver(http.DefaultClient, "https://test-ion-resolution.com")
 		assert.NoError(tt, err)
 		assert.NotEmpty(tt, resolver)
 
-		err = resolver.Anchor(context.Background(), nil)
+		_, err = resolver.Anchor(context.Background(), nil)
 		assert.Error(tt, err)
 		assert.Contains(tt, err.Error(), "anchor operation failed")
 	})
 
 	t.Run("good anchor", func(tt *testing.T) {
 		gock.New("https://test-ion-resolution.com").
 			Post("/operations").
-			Reply(200)
+			Reply(200).
+			BodyString("{}")
 		defer gock.Off()
 
 		resolver, err := NewIONResolver(http.DefaultClient, "https://test-ion-resolution.com")
@@ -170,7 +172,7 @@ func TestResolver(t *testing.T) {
 		assert.NotEmpty(tt, ionDID)
 		assert.NotEmpty(tt, createOp)
 
-		err = resolver.Anchor(context.Background(), createOp)
+		_, err = resolver.Anchor(context.Background(), createOp)
 		assert.NoError(tt, err)
 	})
 }

did/ion/resolver.go

@@ -96,34 +96,39 @@ func (i Resolver) Resolve(ctx context.Context, id string, _ ...resolution.Option
 
 // Anchor submits an anchor operation to the ION node by appending the operations path to the base URL
 // and making a POST request
-func (i Resolver) Anchor(ctx context.Context, op AnchorOperation) error {
+func (i Resolver) Anchor(ctx context.Context, op AnchorOperation) (*resolution.Result, error) {
 	if i.baseURL.String() == "" {
-		return errors.New("resolution URL cannot be empty")
+		return nil, errors.New("resolution URL cannot be empty")
 	}
 	jsonOpBytes, err := json.Marshal(op)
 	if err != nil {
-		return errors.Wrapf(err, "marshalling anchor operation %+v", op)
+		return nil, errors.Wrapf(err, "marshalling anchor operation %+v", op)
 	}
 
 	req, err := http.NewRequestWithContext(ctx, http.MethodPost, strings.Join([]string{i.baseURL.String(), "operations"}, "/"), bytes.NewReader(jsonOpBytes))
 	if err != nil {
-		return errors.Wrap(err, "creating request")
+		return nil, errors.Wrap(err, "creating request")
 	}
 	resp, err := i.client.Do(req)
 	if err != nil {
-		return errors.Wrapf(err, "posting anchor operation %+v", op)
+		return nil, errors.Wrapf(err, "posting anchor operation %+v", op)
 	}
 
 	defer resp.Body.Close()
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
-		return errors.Wrapf(err, "could not resolve with response %+v", resp)
+		return nil, errors.Wrapf(err, "could not resolve with response %+v", resp)
 	}
 	if !is2xxStatusCode(resp.StatusCode) {
-		return fmt.Errorf("anchor operation failed: %s", string(body))
+		return nil, fmt.Errorf("anchor operation failed: %s", string(body))
 	}
 	logrus.Infof("successfully anchored operation: %s", string(body))
-	return nil
+
+	var resolutionResult resolution.Result
+	if err := json.Unmarshal(body, &resolutionResult); err != nil {
+		return nil, errors.Wrap(err, "unmarshalling anchor response")
+	}
+	return &resolutionResult, nil
 }
 
 func (Resolver) Methods() []did.Method {