Simple test that the dragstart event contains the default data in the event.

Select some text in this box and drag it.

Drag the image. 

Drag the link. Link

Test ID: selectionTest
text/plain: Select some text in this box and drag it.
text/url: 
text/html: <span style="color: rgb(0, 0, 0); font-family: serif; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">Select some text in this box and drag it.</span>
Test ID: imageTest
text/plain: 
text/url: 
text/html: <img id="imageTest" src="data:image/png;base64, iVBORw0KGgoAAAANSUhEUgAAAJYAAAA8CAIAAAAL5NQ9AAAACXBIWXMAAAsTAAALEwEAmpwY AAAAB3RJTUUH2woaBQc4oLEFpAAAABl0RVh0Q29tbWVudABDcmVhdGVkIHdpdGggR0lNUFeB DhcAAACMSURBVHja7dNBEYAgFEVRPhHMYgAzUIsmVnFvB/fsoQb+ObfBmzMvxneW1D1vzz2w FiEUQiFEKIRCKIQIhVAIhRChEAqhECIUQiEUQoRCKIRCiFAIhVAIEep3xTWTLzzu5oVCKIRC iFAIhVAIEQqhEAohQiEUQiFEKIRCKIQIhVAIhRChEAqhECLUZi3VEwcBMGr1NgAAAABJRU5E rkJggg==" ondragstart="dragStartTest(event)">
Test ID: linkTest
text/plain: http://www.example.com/
text/url: 
text/html: <a id="linkTest" href="http://www.example.com/" ondragstart="dragStartTest(event)">Link</a>