Fix the wrapping IIFE of the prod bundle

[mgechev]

Currently, the semantics of line 59 in Gruntfile.js is - expose the library as a global called true. This causes two problems:

1. The wrapping mechanism of uglify breaks in strict mode (more below)
2. There's a leaking global variable called true

The used version of uglify wraps the code in the following construct:

"(function(" + parameters.join(",") + "){ '$ORIG'; })(" + args.join(",") + ")";

The IIFE passes the global this to a function and later tries to set the property name that we've assigned to wrap. This works fine in non-strict cases. The only side effect is the global window.true that we set to an empty object. In strict mode, however, global this equals to undefined. We try to set undefined['true'] which cases a runtime error.

We noticed the above scenario after enabling differential loading with script[type="module"], which uses strict mode by default.

It'll be fantastic if we can release the fix today, so we don't block the CLI release.

Side note, the wrap function of uglify is fixed for strict mode here. Maybe update of grunt and grunt-contrib-uglify is worth it.

[alexeagle]

Note, Angular 8 is shipping today and this fix is critical for us, so we'll direct our users to have an npm dependency on web-animations-js@github:angular/web-animations-js#release_pr208 where we have prepared a custom release including this fix

[flackr]

Thanks for the patch. I've verified this still exposes the expected interfaces in the minified bundles as well as working with module imports. I'm unfortunately unable to verify on the test suite due to an unrelated failure.

[viceice]

@flackr Maybe a simple travis retry? Looks like a temporary git problem.

[alancutter]

Looks like Travis is having trouble pulling the w3c repositories it uses to run tests. I don't think it's been run in a long time. I can probably find some cycles to get it running again after branch point.

[alexeagle]

Could we merge and release this even without the green travis? The current release of Angular is using a fork of this project to work around the problem, we'd like to get off our fork before too many users depend on it.

[fbecquier]

Could we try to relaunch a build?

[flackr]

I'm not sure how to fix the travis errors, but having tested manually I'll go ahead and merge this.

[mgechev]

Do you think we can release?

[alan-agius4]

@flackr, can we please get a release for this? Thanks

[dscalzi]

Bump

[kdinev]

Any chance this can get released any time soon?

[alancutter]

Published 2.3.2 including this change, please report if you come across any issues with the new release.