Accumulate timers

[nelsonic]

At present when we stop a timer it disappears from the UI. 🤦‍♂️
Then when we start a new one it does not reflect the previous timers (if there are any) ...
This is obviously not the desired behaviour.
What we want is to:

• Display time elapsed in UI when timer stopped. Always display timer even when no active timer is counting #106
• Accumulate the time elapsed (timer.end - timer.start) for all previous timers
• Subtract accumulated time from the current timer.start so that timers continue counting.

[nelsonic]

making a stab at this now. have a decent idea of how to achieve it. 🧑‍💻 🤞 ⏳

[nelsonic]

The fun part is writing tests ... 💭

[nelsonic]

https://hexdocs.pm/elixir/1.13/Enum.html#reduce/2

[nelsonic]

  1) test accumulate timers #103 accummulate_item_timers/1 to display cummulative timer (App.TimerTest)
     test/app/timer_test.exs:41
     ** (Enum.EmptyError) empty error
     code: acc = Item.accumulate_item_timers(items_with_timers)
     stacktrace:
       (elixir 1.13.4) lib/enum.ex:2342: Enum.reduce/2
       (app 0.1.0) lib/app/item.ex:209: anonymous fn/3 in App.Item.accumulate_item_timers/1
       (elixir 1.13.4) lib/enum.ex:1593: Enum."-map/2-lists^map/1-0-"/2
       (elixir 1.13.4) lib/map.ex:236: Map.new_from_enum/2
       test/app/timer_test.exs:97: (test)

🙄

[nelsonic]

Lucky guess: used Enum.reduce/3 instead of Enum.reduce/2. 🙄

[nelsonic]

I've got this working ... but it's not pretty ... 😕

[nelsonic]

But there's a test and lots of comments so it should be "refactorable" by someone smarter than me. 🤞

[nelsonic]

GIF showing a timer being started, stopped and started again:

Obvs the disappearing timer isn't great UX.
Let's fix that!

GOTO: #106

[nelsonic]

Confident this is working now:

Had to port the timer_text/2 function to Elixir
cause there's a bug in LiveView that means
we can only have one Alpine.js component in a LiveView page:
alpinejs/alpine#911 🤦‍♂️

So server-sided rendering the stopped timer.
Which I actually think makes more sense as it's static. 👍