diff --git a/assets/js/match_query.js b/assets/js/match_query.js
index 618ddcb8..a76d68e4 100644
--- a/assets/js/match_query.js
+++ b/assets/js/match_query.js
@@ -874,7 +874,4 @@ SearchAST.prototype.dumpTree = function() {
   return retStrArr.join('\n');
 };
 
-// Force module handling for Jest, can be removed after TypeScript migration
-export {};
-
 export default parseSearch;
diff --git a/assets/js/utils/__tests__/draggable.spec.ts b/assets/js/utils/__tests__/draggable.spec.ts
index e2786ec1..9c3cd858 100644
--- a/assets/js/utils/__tests__/draggable.spec.ts
+++ b/assets/js/utils/__tests__/draggable.spec.ts
@@ -269,7 +269,7 @@ describe('Draggable Utilities', () => {
         initDraggables();
 
         const mockEvent = createDragEvent('dragstart');
-        const documentClosestSpy = jest.spyOn(mockDraggable, 'closest').mockReturnValue(null);
+        const draggableClosestSpy = jest.spyOn(mockDraggable, 'closest').mockReturnValue(null);
 
         try {
           fireEvent(mockDraggable, mockEvent);
@@ -277,7 +277,7 @@ describe('Draggable Utilities', () => {
           expect(mockEvent.dataTransfer?.effectAllowed).toBeFalsy();
         }
         finally {
-          documentClosestSpy.mockRestore();
+          draggableClosestSpy.mockRestore();
         }
       });
     });
diff --git a/assets/js/utils/draggable.js b/assets/js/utils/draggable.ts
similarity index 51%
rename from assets/js/utils/draggable.js
rename to assets/js/utils/draggable.ts
index 9ac06d9c..f4676dcc 100644
--- a/assets/js/utils/draggable.js
+++ b/assets/js/utils/draggable.ts
@@ -1,11 +1,13 @@
 import { $$ } from './dom';
 
-let dragSrcEl;
+let dragSrcEl: HTMLElement | undefined;
 
-function dragStart(event, target) {
+function dragStart(event: DragEvent, target: HTMLElement) {
   target.classList.add('dragging');
   dragSrcEl = target;
 
+  if (!event.dataTransfer) return;
+
   if (event.dataTransfer.items.length === 0) {
     event.dataTransfer.setData('text/plain', '');
   }
@@ -13,30 +15,34 @@ function dragStart(event, target) {
   event.dataTransfer.effectAllowed = 'move';
 }
 
-function dragOver(event) {
+function dragOver(event: DragEvent) {
   event.preventDefault();
-  event.dataTransfer.dropEffect = 'move';
+  if (event.dataTransfer) {
+    event.dataTransfer.dropEffect = 'move';
+  }
 }
 
-function dragEnter(event, target) {
+function dragEnter(event: DragEvent, target: HTMLElement) {
   target.classList.add('over');
 }
 
-function dragLeave(event, target) {
+function dragLeave(event: DragEvent, target: HTMLElement) {
   target.classList.remove('over');
 }
 
-function drop(event, target) {
+function drop(event: DragEvent, target: HTMLElement) {
   event.preventDefault();
 
+  if (!dragSrcEl) return;
+
   dragSrcEl.classList.remove('dragging');
 
   if (dragSrcEl === target) return;
 
   // divide the target element into two sets of coordinates
-  // and determine how to act based on the relative mouse positioin
+  // and determine how to act based on the relative mouse position
   const bbox = target.getBoundingClientRect();
-  const detX = bbox.left + (bbox.width / 2);
+  const detX = bbox.left + bbox.width / 2;
 
   if (event.clientX < detX) {
     target.insertAdjacentElement('beforebegin', dragSrcEl);
@@ -46,17 +52,21 @@ function drop(event, target) {
   }
 }
 
-function dragEnd(event, target) {
-  dragSrcEl.classList.remove('dragging');
+function dragEnd(event: DragEvent, target: HTMLElement) {
+  dragSrcEl?.classList.remove('dragging');
 
-  $$('.over', target.parentNode).forEach(t => t.classList.remove('over'));
+  if (target.parentNode) {
+    $$('.over', target.parentNode).forEach(t => t.classList.remove('over'));
+  }
 }
 
-function wrapper(func) {
-  return function(event) {
-    if (!event.target.closest) return;
-    const target = event.target.closest('.drag-container [draggable]');
-    if (target) func(event, target);
+function wrapper<E extends Event, T extends Element>(func: (event: E, target: T) => void) {
+  return function(event: E) {
+    const evtTarget = event.target as EventTarget | Element | null;
+    if (evtTarget && 'closest' in evtTarget && typeof evtTarget.closest === 'function') {
+      const target: T | null = evtTarget.closest('.drag-container [draggable]');
+      if (target) func(event, target);
+    }
   };
 }