Missing `htmlSafe` and `isHTMLSafe`

[gentoid]

After bumping Ember to 3.24 in our project I got the following errors:

node_modules/@types/ember/index.d.ts:446:46 - error TS2339: Property 'htmlSafe' does not exist on type 'typeof import("C:/Users/.../node_modules/@ember/string/index")'.

446         const htmlSafe: typeof EmberStringNs.htmlSafe;
                                                 ~~~~~~~~

node_modules/@types/ember/index.d.ts:447:48 - error TS2339: Property 'isHTMLSafe' does not exist on type 'typeof import("C:/Users/.../node_modules/@ember/string/index")'.

447         const isHTMLSafe: typeof EmberStringNs.isHTMLSafe;
                                                   ~~~~~~~~~~

(and a screenshot of the errors if this is helpful)

Interestingly enough, this package exposes TS definitions, and also there're definitions at @types/ember__string. And the latter does expose htmlSafe and isHTMLSafe

[gentoid]

Oh, this topic has been raised already, in #217, and fixed. But no new releases were since then, so obviously clean install of npm's didn't help. Do you by any chance plan to release new version soon?

[ef4]

This continues to be a serious hazard for apps.

The problem is that an addon can pull this package into the build, and it can break an unrelated addon that was relying on the deprecated methods.

Because both ember-source and @ember/string have competing implementations, I have seen it fail inconsistently in very confusing ways:

• working in the browser while failing in fastboot
• working in classic builds but failing in embroider

I am in favor of backporting deprecated implementations. As far as I can tell, we should release 1.x, 2.x, and 3.x patches because even @ember/string 3.x supports ember-source 3.x versions that still contain these methods. And the global nature of addons means it's not really safe to remove them while supporting ember versions that contain them.

[kategengler]

I added versions of these methods that error with explanation in #367