Add ability to transfer compilation errors into runtime.

[rwjblue]

Invoking the CallExpression form with a special option { insertRuntimeErrors: true } will prevent a compile time error and instead inline the error to be thrown at runtime.

So for example if a template compilation is going to error, we would transpile from:

import { hbs } from 'ember-cli-htmlbars';

const layout = hbs('some bad template', { insertRuntimeErrors: true });

And assuming that this compilation would normally throw an error with the message "ZOMG don't do this", you would have the following compilation output:

const layout = function() {
  throw new Error("ZOMG don't do this');
}();

[chancancode]

I assume babel is taking care of escaping for us, is that right?

[rwjblue]

not sure, will test

[rwjblue]

Ya, the error.message itself is already a string, and any valid string will work (including any escaping needed internally).

[ef4]

Having just noticed this, I want to point out that it has stronger compatibility concerns than may be obvious.

v2 addons don't get to bring their own version of ember-cli-htmlbars along. Instead, the hbs macro is considered an always-available language extension. So we really need to never change it in a backward-incompatible way.

This particular change is backward-compatible, so it's not a problem, but it does mean we are committing to supporting this option forever. You can't just rev the major version of ember-cli-htmlbars to change it, because addons won't have any control over the version of ember-cli-htmlbars in use.