feat(upload): accept filter option

README.md

@@ -271,12 +271,15 @@ test('types into the input', () => {
 })
 ```
 
-### `upload(element, file, [{ clickInit, changeInit }])`
+### `upload(element, file, [{ clickInit, changeInit }], [options])`
 
 Uploads file to an `<input>`. For uploading multiple files use `<input>` with
 `multiple` attribute and the second `upload` argument must be array then. Also
 it's possible to initialize click or change event with using third argument.
 
+If `options.applyAccept` is set to `true` and there is an `accept` attribute on
+the element, files that don't match will be discarded.
+
 ```jsx
 import React from 'react'
 import {render, screen} from '@testing-library/react'

src/__tests__/upload.js

@@ -163,3 +163,39 @@ test('should call onChange/input bubbling up the event when a file is selected',
   expect(onInputInput).toHaveBeenCalledTimes(1)
   expect(onInputForm).toHaveBeenCalledTimes(1)
 })
+
+test.each([
+  [true, 'video/*,audio/*', 2],
+  [true, '.png', 1],
+  [true, 'text/csv', 1],
+  [true, '', 4],
+  [false, 'video/*', 4],
+])(
+  'should filter according to accept attribute applyAccept=%s, acceptAttribute=%s',
+  (applyAccept, acceptAttribute, expectedLength) => {
+    const files = [
+      new File(['hello'], 'hello.png', {type: 'image/png'}),
+      new File(['there'], 'there.jpg', {type: 'audio/mp3'}),
+      new File(['there'], 'there.csv', {type: 'text/csv'}),
+      new File(['there'], 'there.jpg', {type: 'video/mp4'}),
+    ]
+    const {element} = setup(`
+    <input 
+      type="file" 
+      accept="${acceptAttribute}" multiple 
+    />
+  `)
+
+    userEvent.upload(element, files, undefined, {applyAccept})
+
+    expect(element.files).toHaveLength(expectedLength)
+  },
+)
+
+test('should not trigger input event for empty list', () => {
+  const {element, eventWasFired} = setup('<input type="file"/>')
+  userEvent.upload(element, [])
+
+  expect(element.files).toHaveLength(0)
+  expect(eventWasFired('input')).toBe(false)
+})

src/upload.js

@@ -3,23 +3,27 @@ import {click} from './click'
 import {blur} from './blur'
 import {focus} from './focus'
 
-function upload(element, fileOrFiles, init) {
+function upload(element, fileOrFiles, init, {applyAccept = false} = {}) {
   if (element.disabled) return
 
   click(element, init)
 
   const input = element.tagName === 'LABEL' ? element.control : element
 
-  const files = (Array.isArray(fileOrFiles)
-    ? fileOrFiles
-    : [fileOrFiles]
-  ).slice(0, input.multiple ? undefined : 1)
+  const files = (Array.isArray(fileOrFiles) ? fileOrFiles : [fileOrFiles])
+    .filter(file => !applyAccept || isAcceptableFile(file, element.accept))
+    .slice(0, input.multiple ? undefined : 1)
 
   // blur fires when the file selector pops up
   blur(element, init)
   // focus fires when they make their selection
   focus(element, init)
 
+  // treat empty array as if the user just closed the file upload dialog
+  if (files.length === 0) {
+    return
+  }
+
   // the event fired in the browser isn't actually an "input" or "change" event
   // but a new Event with a type set to "input" and "change"
   // Kinda odd...
@@ -46,4 +50,22 @@ function upload(element, fileOrFiles, init) {
   })
 }
 
+function isAcceptableFile(file, accept) {
+  if (!accept) {
+    return true
+  }
+
+  const wildcards = ['audio/*', 'image/*', 'video/*']
+
+  return accept.split(',').some(acceptToken => {
+    if (acceptToken[0] === '.') {
+      // tokens starting with a dot represent a file extension
+      return file.name.endsWith(acceptToken)
+    } else if (wildcards.includes(acceptToken)) {
+      return file.type.startsWith(acceptToken.substr(0, acceptToken.length - 1))
+    }
+    return file.type === acceptToken
+  })
+}
+
 export {upload}

typings/index.d.ts

@@ -26,6 +26,10 @@ export interface IClickOptions {
   clickCount?: number
 }
 
+export interface IUploadOptions {
+  applyAccept?: boolean
+}
+
 declare const userEvent: {
   clear: (element: TargetElement) => void
   click: (
@@ -52,6 +56,7 @@ declare const userEvent: {
     element: TargetElement,
     files: FilesArgument,
     init?: UploadInitArgument,
+    options?: IUploadOptions,
   ) => void
   type: <T extends ITypeOpts>(
     element: TargetElement,