docs(unit testing): improve unit testing guide

[jackfranklin]

This commit adds to the unit testing guide:

• add explicit section on additional libraries: Karma, Jasmine and
  angular-mocks and link to the docs for those projects too. Explain the
  benefit and use case for each of these libaries
• Add more fully featured test examples and add more documentation
  around them, in particular the controller test
• more clearly distinguish between the section on principles of testing
  and actual tutorial on writing a test

This should close #8220.

Questions

One thing that I wasn't sure on was if to update the controller tests to not presume the controller is in the global scope. In the original issue (#8220) it says:

I think we talked about the controller syntax in #5076. We agreed to change that for 2.0.

So I left the controllers as is, but it feels beneficial to me to update the controller example. Is there any reason why that can't be done now? That issue mentioned (#5076) is more about the controllerAs syntax, but the main problem with the test example right now is that the controllers are global.

Secondly, the entire discussion about the different ways of dependency injection - most people will be familiar with how Angular does this and hence talking about other mechanisms doesn't seem that worthwhile?

[googlebot]

CLAs look good, thanks!

[IgorMinar]

can you rename this to PasswordController please? We are trying to get rid of the Ctrl suffix because it causes ambiguity.

[jackfranklin]

Done

[btford]

You should also use the DI annotations:

.controller('PasswordController', ['$scope', function PasswordCtrl($scope) { ...

[IgorMinar]

we no longer support controllers in the global scope, so we should not use that in examples.

@btford can you also take a look please?

[jackfranklin]

@IgorMinar so the dependency injection stuff kind of exists here: https://code.angularjs.org/snapshot/docs/guide/di

If we wanted to move the bit about DI that's in this guide, then the above link is probably the best place to put it.

[jackfranklin]

we no longer support controllers in the global scope, so we should not use that in examples.

Cool, that's what I thought. I will update the examples :)

[btford]

Maybe "tools" instead of "libraries." Karma isn't really a "library"

[btford]

The duplication is now gone, and encapsulated within the beforeEach

This reads weirdly to me. Consider something like "We moved duplicate behavior into the beforeEach block" instead.

[btford]

@jackfranklin – when you're done could you squash these commits? Thanks!

[jackfranklin]

@btford how do you feel about moving the section on DI (https://github.com/jackfranklin/angular.js/blob/unit-testing-docs-improving/docs/content/guide/unit-testing.ngdoc#L38) out, and maybe putting it onto this page? https://code.angularjs.org/snapshot/docs/guide/di

It doesn't really make sense to exist here, better to just link off to the DI guide.

Edit: in fact, most of the content on DI that exists in this guide already exists in the DI guide, so maybe it's just a case of getting rid of it?

[btford]

@jackfranklin – totally agree. Move that section to the DI docs, and if you can find a place in the testing docs, link to the moved section.

[btford]

If the info is duplicated you can just drop it.

[jackfranklin]

@btford can you take a look at the last commit? Once it's done I'll squash :)

[btford]

Looks good. Squash away!

[jackfranklin]

Woo! Squished :)

[btford]

Landed as 3109342. Thanks for the awesome work!