file-system-access/showOpenFilePicker-manual.https.html

<!doctype html>
<meta charset=utf-8>

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="resources/test-helpers.js"></script>

<script>

  promise_test(async t => {
    await new Promise(resolve => {
      window.addEventListener('DOMContentLoaded', resolve);
    });
    // Small delay to give chrome's test automation a chance to actually install
    // itself.
    await new Promise(resolve => step_timeout(resolve, 100));

    await window.test_driver.bless(
      'show a file picker.<br />Please select file-system-access/resources/data/testfile.txt');
    const files = await self.showOpenFilePicker({
      multiple: false, types: [
        { description: 'Text files', accept: { ' text/plain ': ['.txt'] } },
        { description: 'Images', accept: { '  image/*  ': ['.jpg', '.jpeg', '.png'] } },
      ],
    });
    assert_true(Array.isArray(files));
    assert_equals(files.length, 1);
    assert_true(files[0] instanceof FileSystemHandle);
    assert_true(files[0] instanceof FileSystemFileHandle);
    assert_equals(files[0].kind, "file");
    assert_equals(files[0].name, 'testfile.txt');
    const file = await files[0].getFile();
    assert_equals(file.name, 'testfile.txt');
    assert_equals(file.size, 13);
    assert_equals(file.type, 'text/plain');
    assert_equals(await file.text(), 'Hello World!\n');

    promise_test(async t => {
      assert_equals(await files[0].queryPermission(), 'granted');
    }, 'showOpenFilePicker returns correct permissions');
  }, 'showOpenFilePicker works');

</script>