[GH-399] Deal damage over time

[ncontinanza]

Motivation

We need to implement the damage over time executions for effects, following the guidelines found in the design document

Closes lambdaclass/afk_gacha_game#399

Summary of changes

• Add executions_over_time to effects
• Process the executions over time when a skill that has one of them is casted.
• Add a test for this new behaviour

How to test it?

Check the tests and play with the skills cooldowns, DoT duration and period to check that the behaviour is the expected one.

Checklist

• Tested the changes locally.
• Reviewed the changes on GitHub, line by line.
• This change requires new documentation.
  • Documentation has been added/updated.

[lotuuu]

The overall implementation is in line with what I had imagined, love it! Left some small code design comments and general details

[lotuuu]

I think there is a really, really edge-y edge case here where this fails still. Do you think we should add an issue to revisit this later?

[ncontinanza]

As discussed, the case in which two units of the same character apply the same EoT to a target would be handled by this comparison because the execution over time would have different values in the caster field.

[lotuuu]

Code is looking fine to me! However I'm getting an error when trying to play a level:

[error] Ranch listener Gateway.Endpoint.HTTP had connection process started with :cowboy_clear:start_link/4 at #PID<0.1514.0> exit with reason: {%Protocol.UndefinedError{protocol: Enumerable, value: nil, description: ""}, [{Enumerable, :impl_for!, 1, [file: ~c"lib/enum.ex", line: 1]}, {Enumerable, :reduce, 3, [file: ~c"lib/enum.ex", line: 166]}, {Enum, :reduce, 3, [file: ~c"lib/enum.ex", line: 4399]}, {Champions.Battle.Simulator, :apply_tags, 4, [file: ~c"lib/champions/battle/simulator.ex", line: 968]}, {Enum, :"-reduce/3-lists^foldl/2-0-", 3, [file: ~c"lib/enum.ex", line: 2528]}, {Champions.Battle.Simulator, :"-process_step_for_effects/1-fun-0-", 4, [file: ~c"lib/champions/battle/simulator.ex", line: 592]}, {Enum, :"-reduce/3-lists^foldl/2-0-", 3, [file: ~c"lib/enum.ex", line: 2528]}, {Champions.Battle.Simulator, :"-process_step_for_effects/1-fun-2-", 2, [file: ~c"lib/champions/battle/simulator.ex", line: 588]}, {Enum, :"-reduce/3-lists^foldl/2-0-", 3, [file: ~c"lib/enum.ex", line: 2528]}, {Champions.Battle.Simulator, :process_step_for_effects, 1, [file: ~c"lib/champions/battle/simulator.ex", line: 579]}, {Champions.Battle.Simulator, :"-simulate_battle/3-fun-0-", 3, [file: ~c"lib/champions/battle/simulator.ex", line: 193]}, {Enumerable.Range, :reduce, 5, [file: ~c"lib/range.ex", line: 538]}, {Enum, :reduce_while, 3, [file: ~c"lib/enum.ex", line: 2582]}, {Champions.Battle.Simulator, :simulate_battle, 3, [file: ~c"lib/champions/battle/simulator.ex", line: 184]}, {Champions.Battle, :run_battle, 3, [file: ~c"lib/champions/battle.ex", line: 61]}, {Ecto.Multi, :apply_operation, 5, [file: ~c"lib/ecto/multi.ex", line: 883]}, {Enum, :"-reduce/3-lists^foldl/2-0-", 3, [file: ~c"lib/enum.ex", line: 2528]}, {Ecto.Multi, :"-apply_operations/5-fun-1-", 5, [file: ~c"lib/ecto/multi.ex", line: 856]}, {Ecto.Adapters.SQL, :"-checkout_or_transaction/4-fun-0-", 3, [file: ~c"lib/ecto/adapters/sql.ex", line: 1358]}, {DBConnection, :run_transaction, 4, [file: ~c"lib/db_connection.ex", line: 1710]}]}

This is the battle:

[agustinesco]

LGTM!