sap/ui/thirdparty/es6-promise does not support promise.finally

[mauriciolauffer]

OpenUI5 version:
All

Any other tested browsers/devices(OK/FAIL):
IE9 FAIL;
Edge FAIL;
Chrome > 62 OK

URL (minimal example if possible):
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/finally

What is the expected result?
After fetch.then or fetch.catch being executed, fetch.finally should be called. Fetch.finally should always be called before concluding the fetch command.

What happens instead?
An error is raised for fetch.finally doesn't exist.

Any other information? (attach screenshot if possible)
Just need to update the es6-promise version, the one being used in UI5 is from 2015 and it's quite outdated.

[codeworrior]

Updating es6-promise makes sense, yes.

But I'm not sure if upgrading the polyfill is sufficient. I tried to find information about what browsers meanwhile support Promise.prototype.finally and the best I could find was https://hospodarets.com/promise.prototype.finally#support (the support table on MDN seems to be outdated).

When comparing this with our browser support matrix, one open question is whether the 'last two versions' of Safari means 11.1 and 11.0 (would be fine) or 11 and 10. If it means the latter, we either would have to activate the es6-promise again on Safari 10 or would have to add another polyfill just for the Promise.prototype.finally. I'll clarify this internally and let you know.

[codeworrior]

Just to give an update:

• es6-promise 4.2.4 didn't work in UI5 out of the box, Opa stumbled about it (reported as Intercepting Promise.resolve fails in enumerator.js#L82 stefanpenner/es6-promise#335, but we can fix this ourselves)
• it seems that we still have to support Safari 10, so the missing Promise.prototype.finally has to be polyfilled there. Interestingly, this is discussed as a general topic for es-promise as well (polyfill() does not polyfill Promise.prototype.finally() if the environment already has a Promise implementation. stefanpenner/es6-promise#330)