33 firebase error handler

[tamari-gray]

fixes #33

Hi nick, went out of scope of ticket by implementing firebase error handling in signinscreen.
I did that so i could write tests for it.

i also had to touch the main,dart file, setting a navService in main(), and feeding the navigaorKey to myapp.
cant remember why we made the authservice in the main() function and not my app but i dont doubt theres a good reason haha.
and i updated the classes in your test files, if the ci tests pass, then im a lucky man.

Not sure if will work on ios

• can you please test on ios for me, im not sure if the error message codes will be the same

[coveralls]

Pull Request Test Coverage Report for Build 204156602

• 15 of 21 (71.43%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-3.03%) to 96.97%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lib/screens/sign_in.dart	4	6	66.67%
lib/services/auth/navigation_service.dart	11	15	73.33%

Totals
Change from base Build 198697977:	-3.03%
Covered Lines:	224
Relevant Lines:	231

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💛 - Coveralls

[nickmeinhold]

Hey mate! Just having a look through now.

cant remember why we made the authservice in the main() function and not my app

It's so we can inject mock services into the MyApp widget - either in a widget test where the widget under test is MyApp (so effectively the whole app) or in integration tests.

can you please test on ios for me, im not sure if the error message codes will be the same

What specifically do you want me to test? What error message code are you expecting?

[nickmeinhold]

Looks great man, awesome work!!!

[nickmeinhold]

@tamari-gray just to follow up on the exceptions question, the exceptions are (as far as I understand) consistent across platforms since flutter/plugins#775 and apparently are being improved to use types: firebase/flutterfire#2653

[tamari-gray]

@nickmeinhold thanks so much for the detailed comments/ explanations & feedback!