<p dir="auto">Additional constructor that takes in HTMLFormElement as parameter as here:</p>
<p dir="auto"><a href="https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest/FormData" rel="nofollow">https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest/FormData</a></p>
<p dir="auto">declare var FormData: {<br>
prototype: FormData;<br>
new (): FormData;<br>
new (form: HTMLFormElement): FormData;<br>
};</p>
<p dir="auto">This is copied from <a href="https://typescript.codeplex.com/workitem/720" rel="nofollow">https://typescript.codeplex.com/workitem/720</a>, the fix isn't incorporated into TS v 1.4.<br>
It's possible to write the constructor in the optional form as well:<br>
new (form?: HTMLFormElement): FormData;</p>
<p dir="auto">Thanks in advance!</p>
<p dir="auto">i'm including a link to this codeplex issue since I believe it's a critical bug that's been incorrectly closed.</p>
<p dir="auto"><a href="https://typescript.codeplex.com/workitem/627" rel="nofollow">https://typescript.codeplex.com/workitem/627</a></p>
<p dir="auto">when combining output into a single .js file, the compiler should NEVER emit derived classes before their base class.</p>
<p dir="auto">this was reported 2 years ago, and it's still not fixed.</p>