html-tag.js is using the .raw version of strings; y tho?

[usergenic]

Description

Consider the template string literal assignment from a recently modulized element iron-a11y-announcer:

html`<div aria-live\$="[[mode]]">[[_text]]</div>`

Note the bound attribute aria-live$= is represented here with an escaped \$ instead of just the $. This is because of a naive, but valid, escaping that takes place when the original html file was ported into the javascript templated string literal in polymer-modulizer.

Polymer html-tag.js, however, uses the .raw value of this literal, resulting in its injection of the escaped character into the DOM, giving everyone binding to attributes the following experience with the current modulized code: https://github.com/Polymer/polymer-modulizer/issues/292

Here's the html-tag code:

polymer/lib/utils/html-tag.html

Line 57 in ee1d71f

const rawStrings = strings.raw;

Can we be clear there's a reason for the html() function to use .raw? Because I don't see a case where you'd want javascript-escape sequences to be literally interpreted when injecting HTML. Is this for convenience of embedding JS source in the template? I think it just makes things even harder to escape inside the embedded JS source then too as a consequence...

[usergenic]

Also, yeah yeah yeah we could always not escape dollar signs or backticks at all in the modulizer, but...