From 4de813bfd59353ae214d02a9fe62b100f81f02e4 Mon Sep 17 00:00:00 2001
From: jamsinclair <jamsinclairnz@gmail.com>
Date: Fri, 8 May 2020 00:10:36 +0900
Subject: [PATCH 1/3] feat(events): Add dataTransfer event property option

---
 src/__tests__/events.js | 21 +++++++++++++++++++++
 src/events.js           | 15 ++++++++++++---
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/__tests__/events.js b/src/__tests__/events.js
index f91cf408..f2f8d2a9 100644
--- a/src/__tests__/events.js
+++ b/src/__tests__/events.js
@@ -282,6 +282,27 @@ test('assigning the files property on an input', () => {
   expect(node.files).toEqual([file])
 })
 
+test('assigns dataTransfer properties', () => {
+  const node = document.createElement('div')
+  const spy = jest.fn()
+  node.addEventListener('dragover', spy)
+  fireEvent.dragOver(node, {dataTransfer: {dropEffect: 'move'}})
+  expect(spy).toHaveBeenCalledTimes(1)
+  expect(spy.mock.calls[0][0]).toHaveProperty('dataTransfer.dropEffect', 'move')
+})
+
+test('assigning the files property on dataTransfer', () => {
+  const node = document.createElement('div')
+  const file = new document.defaultView.File(['(⌐□_□)'], 'chucknorris.png', {
+    type: 'image/png',
+  })
+  const spy = jest.fn()
+  node.addEventListener('drop', spy)
+  fireEvent.drop(node, {dataTransfer: {files: [file]}})
+  expect(spy).toHaveBeenCalledTimes(1)
+  expect(spy.mock.calls[0][0]).toHaveProperty('dataTransfer.files', [file])
+})
+
 test('fires events on Window', () => {
   const messageSpy = jest.fn()
   window.addEventListener('message', messageSpy)
diff --git a/src/events.js b/src/events.js
index 389fdab3..9e9fcd87 100644
--- a/src/events.js
+++ b/src/events.js
@@ -44,19 +44,28 @@ Object.keys(eventMap).forEach(key => {
     Object.assign(node, targetProperties)
     const window = getWindowFromNode(node)
     const EventConstructor = window[EventType] || window.Event
+    let event
     /* istanbul ignore else  */
     if (typeof EventConstructor === 'function') {
-      return new EventConstructor(eventName, eventInit)
+      event = new EventConstructor(eventName, eventInit)
     } else {
       // IE11 polyfill from https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent#Polyfill
-      const event = window.document.createEvent(EventType)
+      event = window.document.createEvent(EventType)
       const {bubbles, cancelable, detail, ...otherInit} = eventInit
       event.initEvent(eventName, bubbles, cancelable, detail)
       Object.keys(otherInit).forEach(eventKey => {
         event[eventKey] = otherInit[eventKey]
       })
-      return event
     }
+
+    // Approximate dataTransfer on the event object
+    // jsdom does not support DataTransfer constructor
+    // https://github.com/testing-library/react-testing-library/issues/339#issuecomment-526310225
+    const {dataTransfer} = eventInit
+    if (typeof dataTransfer === 'object') {
+      Object.assign(event, {dataTransfer})
+    }
+    return event
   }
 
   fireEvent[key] = (node, init) => fireEvent(node, createEvent[key](node, init))

From 7dea4bdf1c5aed6f2418bfe2fe1be88b9478b0bf Mon Sep 17 00:00:00 2001
From: jamsinclair <jamsinclairnz@gmail.com>
Date: Fri, 8 May 2020 02:36:28 +0900
Subject: [PATCH 2/3] update to support DataTransfer constructor

---
 src/events.js | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/events.js b/src/events.js
index 9e9fcd87..94767f1f 100644
--- a/src/events.js
+++ b/src/events.js
@@ -58,12 +58,18 @@ Object.keys(eventMap).forEach(key => {
       })
     }
 
-    // Approximate dataTransfer on the event object
-    // jsdom does not support DataTransfer constructor
-    // https://github.com/testing-library/react-testing-library/issues/339#issuecomment-526310225
     const {dataTransfer} = eventInit
     if (typeof dataTransfer === 'object') {
-      Object.assign(event, {dataTransfer})
+      /* istanbul ignore if  */
+      if (typeof window.DataTransfer === 'function') {
+        Object.defineProperty(event, 'dataTransfer', {
+          value: Object.assign(new window.DataTransfer(), dataTransfer)
+        })
+      } else {
+        Object.defineProperty(event, 'dataTransfer', {
+          value: dataTransfer
+        })
+      }
     }
     return event
   }

From 94d4eaaa1e6dc0daa2b6c0a4d0c8acab246b027b Mon Sep 17 00:00:00 2001
From: "Kent C. Dodds" <me+github@kentcdodds.com>
Date: Thu, 7 May 2020 11:40:40 -0600
Subject: [PATCH 3/3] Update src/events.js

---
 src/events.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/events.js b/src/events.js
index 94767f1f..c54ec589 100644
--- a/src/events.js
+++ b/src/events.js
@@ -60,6 +60,7 @@ Object.keys(eventMap).forEach(key => {
 
     const {dataTransfer} = eventInit
     if (typeof dataTransfer === 'object') {
+      // DataTransfer is not supported in jsdom: https://github.com/jsdom/jsdom/issues/1568
       /* istanbul ignore if  */
       if (typeof window.DataTransfer === 'function') {
         Object.defineProperty(event, 'dataTransfer', {