diff --git a/Changelog.md b/Changelog.md
index a2041dddd3..d48cae06f5 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -39,6 +39,7 @@
 - Updated images: moved externally-hosted images into repository, ensured images are vertically centred and displayed as new paragraphs, and cropped images to remove blank space (#8053)
 
 ### 🔧 Internal changes
+- Refactored annotation routes to respond with JSON rather than Javascript (#8127)
 - Removed `:blob` CSP exception for `img_src` for `groups_controller.rb` and `exam_templates_controller.rb`
 - Replaced `jcrop` with `cropperjs` for the exam template cover page crop selector (#8114)
 - Migrated `image_viewer.jsx` file to use `heic-convert` instead of `heic2any`; Updated CSP exceptions for controllers depending on `image_viewer.jsx` (#8100)
diff --git a/app/controllers/annotations_controller.rb b/app/controllers/annotations_controller.rb
index 700843391b..8e33cf6daa 100644
--- a/app/controllers/annotations_controller.rb
+++ b/app/controllers/annotations_controller.rb
@@ -21,7 +21,7 @@ def add_existing_annotation
       **params.to_unsafe_h.slice(*annotation_class.required_fields).symbolize_keys,
       **base_attributes
     )
-    render :create
+    render json: @annotation.to_json(current_role: current_role)
   end
 
   def create
@@ -62,6 +62,7 @@ def create
       **params.to_unsafe_h.slice(*annotation_class.required_fields).symbolize_keys,
       **base_attributes
     )
+    render json: @annotation.to_json(current_role: current_role)
   end
 
   def destroy
@@ -79,6 +80,7 @@ def destroy
       end
     end
     text = @annotation.annotation_text
+    annotation_text_id = @annotation.annotation_text_id
     text.destroy if text.annotation_category_id.nil?
     @annotation.destroy
     result.annotations.reload.each do |annot|
@@ -86,6 +88,7 @@ def destroy
         annot.update(annotation_number: annot.annotation_number - 1)
       end
     end
+    render json: { id: @annotation.id, annotation_text_id: annotation_text_id }
   end
 
   def update
@@ -99,7 +102,7 @@ def update
     end
 
     change_all = !params[:annotation_text] || !params[:annotation_text][:change_all] ||
-        params[:annotation_text][:change_all] == '1'
+        params[:annotation_text][:change_all].to_s == '1'
     if change_all
       @annotation_text.update(content: params[:content])
     else
@@ -114,6 +117,7 @@ def update
         @annotation.update(annotation_text: new_text)
       end
     end
+    render json: { annotation: @annotation.reload.get_data(include_creator: true) }
   end
 
   protected
diff --git a/app/javascript/Components/Result/result.jsx b/app/javascript/Components/Result/result.jsx
index 26e1c2b52e..09479cc0cb 100644
--- a/app/javascript/Components/Result/result.jsx
+++ b/app/javascript/Components/Result/result.jsx
@@ -296,6 +296,14 @@ class Result extends React.Component {
   };
 
   /* Callbacks for annotations */
+  // Headers for annotation routes, which are submitted as JSON via fetch rather than
+  // through jQuery, so the CSRF token needs to be attached by hand.
+  jsonHeaders = () => ({
+    "Content-Type": "application/json",
+    Accept: "application/json",
+    "X-CSRF-Token": document.querySelector('[name="csrf-token"]').content,
+  });
+
   newAnnotation = () => {
     const submission_file_id =
       this.leftPane.current.submissionFilePanel.current.state.selectedFile[1];
@@ -315,14 +323,18 @@ class Result extends React.Component {
 
     let onSubmit = formData => {
       let data = {...formData, ...metadata};
-      return $.post({
-        url: Routes.course_annotations_path(this.props.course_id),
-        data,
-      }).then(() => {
-        this.setState({
-          annotationModal: INITIAL_ANNOTATION_MODAL_STATE,
-        });
-      }); // Resetting back to original
+      return fetch(Routes.course_annotations_path(this.props.course_id), {
+        method: "POST",
+        headers: this.jsonHeaders(),
+        body: JSON.stringify(data),
+      })
+        .then(response => response.json())
+        .then(json => {
+          this.addAnnotation(json.annotation, json.mark_update);
+          this.setState({
+            annotationModal: INITIAL_ANNOTATION_MODAL_STATE,
+          });
+        }); // Resetting back to original
     };
 
     this.setState({
@@ -355,27 +367,20 @@ class Result extends React.Component {
     }
   };
 
-  addAnnotation = (
-    annotation,
-    criterion_id = null,
-    mark_value = null,
-    new_subtotal = null,
-    new_total = null,
-    new_num_marked = null
-  ) => {
+  addAnnotation = (annotation, markUpdate = null) => {
     this.setState({annotations: this.state.annotations.concat([annotation])});
 
-    if (!!criterion_id) {
+    if (markUpdate) {
       let newMarks = [...this.state.marks];
-      let i = newMarks.findIndex(m => m.id === criterion_id);
+      let i = newMarks.findIndex(m => m.id === markUpdate.criterion_id);
       if (i >= 0) {
         newMarks[i] = {...newMarks[i]};
-        newMarks[i].mark = mark_value;
+        newMarks[i].mark = markUpdate.mark;
         this.setState({
           marks: newMarks,
-          subtotal: new_subtotal,
-          total: new_total,
-          num_marked: new_num_marked,
+          subtotal: markUpdate.subtotal,
+          total: markUpdate.total,
+          num_marked: markUpdate.num_marked,
         });
       }
     }
@@ -404,7 +409,15 @@ class Result extends React.Component {
 
     data = this.extend_with_selection_data(data);
     if (data) {
-      $.post(Routes.add_existing_annotation_course_annotations_path(this.props.course_id), data);
+      fetch(Routes.add_existing_annotation_course_annotations_path(this.props.course_id), {
+        method: "POST",
+        headers: this.jsonHeaders(),
+        body: JSON.stringify(data),
+      })
+        .then(response => response.json())
+        .then(json => {
+          this.addAnnotation(json.annotation, json.mark_update);
+        });
     }
   };
 
@@ -424,7 +437,15 @@ class Result extends React.Component {
 
     data = this.extend_with_selection_data(data);
     if (data) {
-      $.post(Routes.course_annotations_path(this.props.course_id), data, undefined, "script");
+      fetch(Routes.course_annotations_path(this.props.course_id), {
+        method: "POST",
+        headers: this.jsonHeaders(),
+        body: JSON.stringify(data),
+      })
+        .then(response => response.json())
+        .then(json => {
+          this.addAnnotation(json.annotation, json.mark_update);
+        });
     }
   };
 
@@ -468,18 +489,24 @@ class Result extends React.Component {
 
     let onSubmit = formData => {
       let data = {...formData, ...metadata};
-      $.ajax({
-        url: Routes.course_annotation_path(this.props.course_id, annot_id),
-        data,
+      return fetch(Routes.course_annotation_path(this.props.course_id, annot_id), {
         method: "PUT",
-        dataType: "json",
-      }).always(() => {
-        this.setState({
-          annotationModal: INITIAL_ANNOTATION_MODAL_STATE,
+        headers: this.jsonHeaders(),
+        body: JSON.stringify(data),
+      })
+        .then(response => (response.ok ? response.json() : null))
+        .then(json => {
+          if (json) {
+            this.updateAnnotation(json.annotation);
+          }
+        })
+        .finally(() => {
+          this.setState({
+            annotationModal: INITIAL_ANNOTATION_MODAL_STATE,
+          });
+          this.refreshAnnotations();
+          this.refreshAnnotationCategories();
         });
-        this.refreshAnnotations();
-        this.refreshAnnotationCategories();
-      });
     };
 
     let annotation = this.state.annotations.find(
@@ -543,7 +570,7 @@ class Result extends React.Component {
     }
   }
 
-  destroyAnnotation(annotation_id, range, annotation_text_id) {
+  destroyAnnotation(annotation_id, annotation_text_id) {
     if (
       !!window.annotation_manager &&
       window.annotation_manager.annotation_text_manager.annotationTextExists(annotation_text_id)
@@ -565,15 +592,21 @@ class Result extends React.Component {
   }
 
   removeAnnotation = annot_id => {
-    $.ajax({
-      url: Routes.course_annotation_path(this.props.course_id, annot_id),
+    fetch(Routes.course_annotation_path(this.props.course_id, annot_id), {
       method: "DELETE",
-      data: {
+      headers: this.jsonHeaders(),
+      body: JSON.stringify({
         result_id: this.state.result_id,
         assignment_id: this.state.assignment_id,
-      },
-      dataType: "script",
-    }).then(this.fetchData);
+      }),
+    })
+      .then(response => (response.ok ? response.json() : null))
+      .then(json => {
+        if (json) {
+          this.destroyAnnotation(json.id, json.annotation_text_id);
+        }
+      })
+      .then(this.fetchData);
   };
 
   /* Callbacks for RightPane */
@@ -1026,12 +1059,9 @@ class Result extends React.Component {
                   submission_files={this.state.submission_files}
                   student_view={this.props.role === "Student"}
                   newAnnotation={this.newAnnotation}
-                  addAnnotation={this.addAnnotation}
                   addExistingAnnotation={this.addExistingAnnotation}
                   editAnnotation={this.editAnnotation}
-                  updateAnnotation={this.updateAnnotation}
                   removeAnnotation={this.removeAnnotation}
-                  destroyAnnotation={this.destroyAnnotation}
                   rmd_convert_enabled={this.props.rmd_convert_enabled}
                 />
               </Panel>
diff --git a/app/models/annotation.rb b/app/models/annotation.rb
index 9d81997023..f0fce5a5f7 100644
--- a/app/models/annotation.rb
+++ b/app/models/annotation.rb
@@ -105,6 +105,28 @@ def get_data(include_creator: false)
     data
   end
 
+  # Serializes this annotation for the Result component. When the annotation carries a
+  # deduction that isn't overridden, also includes the updated mark/subtotal/total so
+  # the front end can reflect the deduction without a full refetch.
+  def to_json(current_role: nil)
+    data = { annotation: get_data(include_creator: true) }
+
+    criterion = annotation_text.annotation_category&.flexible_criterion
+    mark = result.marks.find_by(criterion: criterion)
+    unless annotation_text.deduction.nil? || annotation_text.deduction == 0 || mark.override
+      grader_id = current_role&.instructor? ? nil : current_role&.id
+      data[:mark_update] = {
+        criterion_id: criterion.id,
+        mark: mark.mark,
+        subtotal: result.get_subtotal,
+        total: result.get_total_mark,
+        num_marked: result.grouping.assignment.get_num_marked(grader_id)
+      }
+    end
+
+    data.to_json
+  end
+
   private
 
   # check if the submission file is associated with a remark result or a released result
diff --git a/app/views/annotations/create.js.erb b/app/views/annotations/create.js.erb
deleted file mode 100755
index 6d402a9027..0000000000
--- a/app/views/annotations/create.js.erb
+++ /dev/null
@@ -1,52 +0,0 @@
-(function () {
-  annotation_details = {
-    id: <%= @annotation.id %>,
-    creator: '<%= "#{@annotation.creator.display_name}" %>',
-    filename: '<%= @annotation.submission_file.filename %>',
-    path: '<%= @annotation.submission_file.path.split('/', 2)[1] %>',
-    submission_file_id: <%= @annotation.submission_file_id %>,
-    content: '<%= @annotation.annotation_text.escape_content %>',
-    annotation_category: '<%= @annotation.annotation_text.annotation_category&.annotation_category_name %>',
-    annotation_text_id: <%= @annotation.annotation_text_id %>,
-    criterion_id: <%= @annotation.annotation_text.annotation_category&.flexible_criterion_id || 'undefined' %>,
-    criterion_name: '<%= @annotation.annotation_text.annotation_category&.flexible_criterion&.name %>' || undefined,
-    deduction: <%= @annotation.annotation_text.deduction || 'undefined' %>,
-    type: '<%= @annotation.class.name %>',
-    number: <%= @annotation.annotation_number %>,
-    is_remark: <%= @annotation.is_remark %>,
-    line_start: <%= @annotation.line_start || 'undefined' %>,
-    line_end: <%= @annotation.line_end || 'undefined' %>,
-    column_start: <%= @annotation.column_start || 'undefined' %>,
-    column_end: <%= @annotation.column_end || 'undefined' %>,
-    page: <%= @annotation.page || 'undefined' %>,
-    x_range: {
-      start: <%= [@annotation.x1, @annotation.x2].min || 'undefined' %>,
-      end: <%= [@annotation.x1, @annotation.x2].max || 'undefined' %>
-    },
-    y_range: {
-      start: <%= [@annotation.y1, @annotation.y2].min || 'undefined' %>,
-      end: <%= [@annotation.y1, @annotation.y2].max || 'undefined' %>
-    },
-    start_node: <%= (@annotation.start_node || '').to_json.html_safe %>,
-    start_offset: <%= @annotation.start_offset || 'undefined' %>,
-    end_node: <%= (@annotation.end_node || '').to_json.html_safe %>,
-    end_offset: <%= @annotation.end_offset || 'undefined' %>
-  };
-
-  <% deduction = @annotation.annotation_text.deduction %>
-  <% mark = @annotation.result
-                       .marks
-                       .find_by(criterion: @annotation.annotation_text&.annotation_category&.flexible_criterion) %>
-  <% if deduction.nil? || deduction == 0 || mark.override %>
-    resultComponent.current.addAnnotation(annotation_details);
-  <% else %>
-    resultComponent.current.addAnnotation(
-      annotation_details,
-      <%= @annotation.annotation_text.annotation_category.flexible_criterion_id %>,
-      <%= mark.mark %>,
-      <%= @annotation.result.get_subtotal %>,
-      <%= @annotation.result.get_total_mark %>,
-      <%= @annotation.result.grouping.assignment.get_num_marked(@current_role.instructor? ? nil : @current_role.id) %>
-    );
-  <% end %>
-})();
diff --git a/app/views/annotations/destroy.js.erb b/app/views/annotations/destroy.js.erb
deleted file mode 100644
index 68c3018a62..0000000000
--- a/app/views/annotations/destroy.js.erb
+++ /dev/null
@@ -1,6 +0,0 @@
-resultComponent.current.destroyAnnotation(
-  <%= @annotation.id %>,
-  { start: '<%= @annotation.line_start %>',
-    end: '<%= @annotation.line_end %>' },
-  <%= @annotation.annotation_text.id %>
-);
diff --git a/app/views/annotations/update.js.erb b/app/views/annotations/update.js.erb
deleted file mode 100644
index 501f45c751..0000000000
--- a/app/views/annotations/update.js.erb
+++ /dev/null
@@ -1,6 +0,0 @@
-resultComponent.current.updateAnnotation({
-  id: <%= @annotation.id %>,
-  annotation_text_id: <%= @annotation.annotation_text.id %>,
-  content: '<%= @annotation.annotation_text.escape_content %>',
-  annotation_category: '<%= @annotation.annotation_text.annotation_category&.annotation_category_name %>',
-});
diff --git a/spec/controllers/annotations_controller_spec.rb b/spec/controllers/annotations_controller_spec.rb
index 800c9088ab..59d4621fdd 100644
--- a/spec/controllers/annotations_controller_spec.rb
+++ b/spec/controllers/annotations_controller_spec.rb
@@ -44,7 +44,7 @@
                 :add_existing_annotation,
                 params: { annotation_text_id: annotation_text.id, submission_file_id: submission_file.id, line_start: 1,
                           line_end: 1, column_start: 1, column_end: 1, result_id: result.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -55,7 +55,7 @@
                 :add_existing_annotation,
                 params: { annotation_text_id: annotation_text.id, submission_file_id: image_submission_file.id,
                           x1: 0, x2: 1, y1: 0, y2: 1, result_id: result.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -67,7 +67,7 @@
                 params: { annotation_text_id: annotation_text.id, submission_file_id: notebook_submission_file.id,
                           start_node: 'a', start_offset: 1, end_node: 'b', end_offset: 0, result_id: result.id,
                           course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -82,7 +82,7 @@
                   params: { annotation_text_id: annotation_text.id, submission_file_id: rmd_submission_file.id,
                             start_node: 'a', start_offset: 1, end_node: 'b', end_offset: 0, result_id: result.id,
                             course_id: course.id },
-                  format: :js
+                  format: :json
 
           expect(response).to have_http_status(:success)
           expect(result.annotations.reload.size).to eq 1
@@ -98,7 +98,7 @@
                   params: { annotation_text_id: annotation_text.id, submission_file_id: rmd_submission_file.id,
                             line_start: 1, line_end: 1, column_start: 1, column_end: 1, result_id: result.id,
                             course_id: course.id },
-                  format: :js
+                  format: :json
 
           expect(response).to have_http_status(:success)
           expect(result.annotations.reload.size).to eq 1
@@ -110,7 +110,7 @@
                 :add_existing_annotation,
                 params: { annotation_text_id: annotation_text.id, submission_file_id: pdf_submission_file.id,
                           x1: 0, x2: 1, y1: 0, y2: 1, page: 1, result_id: result.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -122,7 +122,7 @@
                   :add_existing_annotation,
                   params: { annotation_text_id: annotation_text.id, submission_file_id: submission_file.id,
                             result_id: result.id, course_id: course.id },
-                  format: :js
+                  format: :json
         end.to raise_error(ActiveRecord::RecordInvalid)
         expect(result.annotations.reload).to be_empty
       end
@@ -135,10 +135,16 @@
                 params: { content: annotation_text.content, category_id: annotation_category.id,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
+        json = response.parsed_body
+        created_annotation = result.annotations.first
+        expect(json['annotation']['id']).to eq created_annotation.id
+        expect(json['annotation']['content']).to eq annotation_text.content
+        expect(json['annotation']['line_start']).to eq 1
+        expect(json['annotation']['line_end']).to eq 1
       end
 
       it 'successfully uses an existing one-time-only text annotation' do
@@ -148,7 +154,7 @@
                           annotation_text_id: annotation_text_oto.id, category_id: nil,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -160,7 +166,7 @@
                           annotation_text_id: annotation_text_oto.id, category_id: nil,
                           submission_file_id: submission_file.id, line_start: 2, line_end: 2, column_start: 2,
                           column_end: 2, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 2
         expect(AnnotationText.all.size).to eq 3
@@ -173,7 +179,7 @@
                           annotation_text_id: annotation_text.id, category_id: annotation_category.id,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -185,7 +191,7 @@
                           annotation_text_id: annotation_text.id, category_id: annotation_category.id,
                           submission_file_id: submission_file.id, line_start: 2, line_end: 2, column_start: 2,
                           column_end: 2, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 2
         expect(AnnotationText.all.size).to eq 1
@@ -198,7 +204,7 @@
                           annotation_text_id: annotation_text_oto.id, category_id: annotation_category.id,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -213,7 +219,7 @@
                           annotation_text_id: annotation_text.id, category_id: new_category.id,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -227,7 +233,7 @@
                           annotation_text_id: annotation_text.id, category_id: nil,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -243,10 +249,13 @@
                 params: { content: annotation_text.content, category_id: annotation_category.id,
                           submission_file_id: image_submission_file.id, x1: 0, x2: 1, y1: 0, y2: 1,
                           result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:ok)
         expect(result.annotations.reload.size).to eq 1
+        json = response.parsed_body
+        expect(json['annotation']['x_range']).to eq({ 'start' => 0, 'end' => 1 })
+        expect(json['annotation']['y_range']).to eq({ 'start' => 0, 'end' => 1 })
       end
 
       it 'successfully creates a PDF annotation' do
@@ -255,7 +264,7 @@
                 params: { content: annotation_text.content, category_id: annotation_category.id,
                           submission_file_id: pdf_submission_file.id, x1: 0, x2: 1, y1: 0, y2: 1, page: 1,
                           result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:ok)
         expect(result.annotations.reload.size).to eq 1
@@ -268,7 +277,7 @@
                           submission_file_id: notebook_submission_file.id, start_node: 'a', start_offset: 1,
                           end_node: 'b', end_offset: 0, result_id: result.id, assignment_id: assignment.id,
                           course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 1
@@ -283,7 +292,7 @@
                   params: { annotation_text_id: annotation_text.id, submission_file_id: rmd_submission_file.id,
                             start_node: 'a', start_offset: 1, end_node: 'b', end_offset: 0, result_id: result.id,
                             course_id: course.id },
-                  format: :js
+                  format: :json
 
           expect(response).to have_http_status(:success)
           expect(result.annotations.reload.size).to eq 1
@@ -299,7 +308,7 @@
                   params: { annotation_text_id: annotation_text.id, submission_file_id: rmd_submission_file.id,
                             line_start: 1, line_end: 1, column_start: 1, column_end: 1, result_id: result.id,
                             course_id: course.id },
-                  format: :js
+                  format: :json
 
           expect(response).to have_http_status(:success)
           expect(result.annotations.reload.size).to eq 1
@@ -316,12 +325,39 @@
                 params: { content: 'I like icecream!', category_id: category.id,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 2
         expect(result.annotations.joins(:annotation_text).where('annotation_texts.deduction': 0).size).to eq 1
       end
+
+      it 'includes a mark_update when reusing a deductive annotation text that is not overridden' do
+        assignment = create(:assignment_with_deductive_annotations)
+        result = assignment.groupings.first.current_result
+        existing_annotation = result.annotations.first
+        deductive_text = existing_annotation.annotation_text
+        submission_file = create(:submission_file, submission: result.submission)
+
+        post_as user,
+                :add_existing_annotation,
+                params: { annotation_text_id: deductive_text.id, submission_file_id: submission_file.id,
+                          line_start: 2, line_end: 2, column_start: 1, column_end: 1, result_id: result.id,
+                          course_id: course.id },
+                format: :json
+
+        expect(response).to have_http_status(:success)
+        json = response.parsed_body
+        criterion = deductive_text.annotation_category.flexible_criterion
+        mark = result.marks.find_by(criterion: criterion)
+        expect(json['mark_update']).to eq(
+          'criterion_id' => criterion.id,
+          'mark' => mark.mark,
+          'subtotal' => result.get_subtotal,
+          'total' => result.get_total_mark,
+          'num_marked' => assignment.get_num_marked(user.instructor? ? nil : user.id)
+        )
+      end
     end
 
     describe '#destroy' do
@@ -337,10 +373,13 @@
                   :destroy,
                   params: { id: anno.id, submission_file_id: submission_file.id, assignment_id: assignment.id,
                             result_id: result.id, course_id: course.id },
-                  format: :js
+                  format: :json
 
         expect(response).to have_http_status(:success)
         expect(result.annotations.reload.size).to eq 0
+        json = response.parsed_body
+        expect(json['id']).to eq anno.id
+        expect(json['annotation_text_id']).to eq anno.annotation_text_id
       end
 
       it 'destroys an annotation when there are multiple annotations for the result' do
@@ -359,7 +398,7 @@
                   :destroy,
                   params: { id: annotations[1].id, submission_file_id: submission_file.id, assignment_id: assignment.id,
                             result_id: result.id, course_id: course.id },
-                  format: :js
+                  format: :json
 
         expect(response).to have_http_status(:success)
 
@@ -382,7 +421,7 @@
                   :destroy,
                   params: { id: anno.id, submission_file_id: submission_file.id, assignment_id: assignment.id,
                             result_id: result.id, course_id: course.id },
-                  format: :js
+                  format: :json
 
         expect(AnnotationText.exists?(annotation_text.id)).to be true
       end
@@ -400,7 +439,7 @@
                   :destroy,
                   params: { id: anno.id, submission_file_id: submission_file.id, assignment_id: assignment.id,
                             result_id: result.id, course_id: course.id },
-                  format: :js
+                  format: :json
 
         expect(AnnotationText.exists?(new_text.id)).to be false
       end
@@ -418,9 +457,12 @@
                :update,
                params: { id: anno.id, assignment_id: assignment.id, submission_file_id: submission_file.id,
                          result_id: result.id, content: 'new content', course_id: course.id },
-               format: :js
+               format: :json
         expect(response).to have_http_status(:success)
         expect(anno.annotation_text.reload.content).to eq 'new content'
+        json = response.parsed_body
+        expect(json['annotation']['id']).to eq anno.id
+        expect(json['annotation']['content']).to eq 'new content'
       end
 
       it 'successfully updates a singular annotation text' do
@@ -444,7 +486,7 @@
                params: { id: anno1.id, assignment_id: assignment.id, submission_file_id: submission_file.id,
                          result_id: result.id, content: 'new content', annotation_text: { change_all: '0' },
                          course_id: course.id },
-               format: :js
+               format: :json
         expect(response).to have_http_status(:success)
         expect(anno1.reload.annotation_text.reload.content).to eq 'new content'
         expect(anno2.reload.annotation_text.reload.content).not_to eq 'new content'
@@ -470,7 +512,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(annotation.reload.annotation_text.content).to eq 'New content!'
       end
 
@@ -485,7 +527,7 @@
                           course_id: course.id,
                           result_id: other_grouping.current_result.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(response).to have_http_status(:bad_request)
         expect(annotation.reload.annotation_text.content).not_to eq 'New content!'
       end
@@ -497,7 +539,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(result.reload.annotations.size).to eq 0
       end
 
@@ -509,7 +551,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(result.reload.annotations.size).to eq 0
       end
     end
@@ -533,7 +575,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(response).to have_http_status(:bad_request)
         expect(annotation.reload.annotation_text.content).not_to eq 'New content!'
       end
@@ -550,7 +592,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(response).to have_http_status(:bad_request)
         expect(annotation.reload.annotation_text.content).not_to eq 'New content!'
       end
@@ -565,7 +607,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(response).to have_http_status(:bad_request)
         expect(result.reload.annotations.size).to eq 1
       end
@@ -580,7 +622,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(result.reload.annotations.size).to eq 0
       end
 
@@ -592,7 +634,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(response).to have_http_status(:bad_request)
         expect(result.reload.annotations.size).to eq 1
       end
@@ -604,7 +646,7 @@
                           result_id: result.id,
                           course_id: course.id,
                           assignment_id: assignment.id },
-                format: :js
+                format: :json
         expect(result.reload.annotations.size).to eq 0
       end
     end
@@ -619,7 +661,7 @@
                 :add_existing_annotation,
                 params: { annotation_text_id: annotation_text.id, submission_file_id: submission_file.id, line_start: 1,
                           line_end: 1, column_start: 1, column_end: 1, result_id: result.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(subject).to respond_with(:forbidden)
         expect(result.annotations.reload.size).to eq 0
@@ -633,7 +675,7 @@
                 params: { content: annotation_text.content, category_id: annotation_category.id,
                           submission_file_id: submission_file.id, line_start: 1, line_end: 1, column_start: 1,
                           column_end: 1, result_id: result.id, assignment_id: assignment.id, course_id: course.id },
-                format: :js
+                format: :json
 
         expect(subject).to respond_with(:forbidden)
         expect(result.annotations.reload.size).to eq 0
@@ -652,7 +694,7 @@
                   :destroy,
                   params: { id: anno.id, submission_file_id: submission_file.id, assignment_id: assignment.id,
                             result_id: result.id, course_id: course.id },
-                  format: :js
+                  format: :json
 
         expect(subject).to respond_with(:forbidden)
         expect(result.annotations.reload.size).to eq 1
@@ -671,7 +713,7 @@
                :update,
                params: { id: anno.id, assignment_id: assignment.id, submission_file_id: submission_file.id,
                          result_id: result.id, content: 'new content', course_id: course.id },
-               format: :js
+               format: :json
         expect(subject).to respond_with(:forbidden)
         expect(anno.annotation_text.reload.content).not_to eq 'new content'
       end