do not auto insert attribute quotes in template literals inside of lit-html

[markcellus]

For some reason, prettier is adding quotes around JS objects in template literals that I need to pass as properties to lit-html. See example below.

Prettier 1.15.2
Playground link

--jsx-single-quote
--parser typescript

Input:

function HelloWorld() {
	const obj = {};
	return html`<my-element obj=${obj}></my-element>`;
}

Output:

function HelloWorld() {
  const obj = {};
  return html`
    <my-element obj="${obj}"></my-element>
  `;
}

Expected behavior:

I expect for quotes not to be inserted around ${obj} because I want to pass the object as it is.
Note, however, that the quotes are not added if I'm not using lit-html's html parser.