feat($time): create time service

[marcin-wosinek]

Add simple $time service to allow easier mocking dates in applications.

Closes #10402

[googlebot]

CLAs look good, thanks!

[lgalfaso]

how is this different from https://docs.angularjs.org/api/ngMock/type/angular.mock.TzDate ?

[caitp]

TzDate is great for testing, but I think we could use $time to move some logic from the date filter and date input handlers into a more logical and re-usable place, which is why I said it would be nice to do it

[lgalfaso]

do you think that there will be more properties added to $time ?

[lgalfaso]

I think that just returning a function would be better

[marcin-wosinek]

I actually return function - the doc was wrong.

[caitp]

Returning $window.Date.now rather than an object would actually make mocking harder

[marcin-wosinek]

The options we have here:

// 1
this.now = $window.Date.now;

// 2
this.now = function() {
  return new Date();
};

1. Was requested in $time service #10402 and is implemented in PR
2. Is what what you @caitp call object? I've build something like this in my project, and it worked nice.

[lgalfaso]

I still think that $time should be a function (that is a wrap that calls $window.Date()), just like what we have for $timeout. Mocks can be done in the same way

[caitp]

it's problematic if we do want to put functionality for date filter/date input on it, because those then become harder to mock.

[marcin-wosinek]

With $timeout we just wrap one function inside the other. Here I can imaging that later we will want to have other properties. $time.now() is easier to extend, $time() seems only to be a bit shorter. And it should be called $now then.

[lgalfaso]

it's problematic if we do want to put functionality for date filter/date input on it, because those then become harder to mock.

why is this different than $timeout ?

[caitp]

$timeout only has one custom method to mock, we'd potentially have 3, possibly more

[lgalfaso]

@caitp I think you are right, this would be a good addition

[PatrickJS]

why not $date?

[lgalfaso]

@gdi2290 $date works for me

[marcin-wosinek]

@lgalfaso - do you have some sugestions about tests? I feel that the current one are not really valuable.

[lgalfaso]

@manuel-woelker sorry for the late response. Even when the PR looks good if we are just looking at the core, I think it is important that there is a reasonable counterpart for ng-mock. This is going to take a little bit more time to get done right, but I would still would like to aim at 1.4

[marcin-wosinek]

Could you provide example of what should this ng-mock counterpart do? I can think only of some $date.setTime(), but this can be acomplished by just mocking the normal fuction

[lgalfaso]

Here is the first draft
https://docs.google.com/document/d/1nkTDEd6yaV9KWEqXEuqHjFzt3WtZ_WNVFC1vA1la0ts/edit#heading=h.csrxcq4wx70q

Note: This is still an early draft so it may change entirely or not be done
at all

[marcin-wosinek]

Ah, that looks like a pretty big change. Is there separate ticket for that? There is #10402, but it's defined much simpler.

btw

Keep a unified queue of elements that are triggered thru $timeout and $interval

should this be something like
0 => now
+100ms => interval 1
+200ms => interval 2
+250ms => timeout

So the queue will know that there should be two intervals fired before timeout?

[lgalfaso]

So the queue will know that there should be two intervals fired before timeout?

yes, and also that $time.now() (or however we call it) also moves forward the right number of ms

[petebacondarwin]

This should land in 1.5 - @lgalfaso can you manage it?

[lgalfaso]

This should land in 1.5 - @lgalfaso https://github.com/lgalfaso can you
manage it?

I will take care

[gkalpak]

Shouldn't this be $DateProvider ?

[gkalpak]

@lgalfaso, I am kind of confused. Is there some followup planned with more features ?

From the discussion above, I got the impression this would be more feature-rich/involved.
In the current state it's essentially a wrapper for Date(). What is the benefit of using $date over just using $window.Date ?

[petebacondarwin]

When I said "this should land", I hadn't actually reviewed this, by the way ;-P

[lgalfaso]

Let me revert this

[gkalpak]

When I said "this should land", I hadn't actually reviewed this, by the way ;-P

Wait...whaat ?! We should actually review the PRs before LGTM'ing ? 😛

[petebacondarwin]

'This Should Land In One Point Five' (TSLIOPF) does not start with the letters L.G.T.M, as far as I can tell.
For the avoidance of doubt: where I said such a thing I really meant that we should work on the issue or pull request once we are in 1.5 mode.

[petebacondarwin]

@lgalfaso - we probably don't need a revert just a bit of additional polish, right?

[lgalfaso]

reverted this with 7dcfe5e