feat: Add module that retrieves system-status relevant alerts #2327
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| subway_alerts_for_today(Timex.now()) | ||
| end | ||
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| defp subway_alerts_for_today(now) do |
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Maybe rename this function to subway_alerts_for_day. That would make more sense with the function above. It's also confusing to name this argument now as it can be any time.
| """ | ||
| @relevant_effects [:delay, :shuttle, :suspension, :station_closure] | ||
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| defp has_started?(active_period_start, now) do |
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Same thing with all of these. now should be a more generic date_time or something.
| ...> ) | ||
| false | ||
| """ | ||
| def active_today?(alert, now) do |
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Same as above, I would name this active_on_day? since it can take any time.
| Given a list of alerts, filters only the ones that are active today, as defined in `&active_today?/2`. | ||
| See that function for details | ||
| """ | ||
| def for_today(alerts, now) do |
| now |> Timex.end_of_day() |> Timex.after?(active_period_start) | ||
| end | ||
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| defp has_not_ended?(nil, _now) do |
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We put all public functions higher in the module than all private functions. I generally try to alphabetize them in order as well.
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| alias Dotcom.SystemStatus.Alerts | ||
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| defp local_datetime(naive) do |
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We usually put private functions at the bottom of the file, though, tbh, not sure we need this. See below.
| local_datetime(~N[2025-01-09 12:00:00]), | ||
| local_datetime(~N[2025-01-09 20:00:00]) |
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Rather than hardcoding these, you can use Faker: https://hexdocs.pm/faker/Faker.DateTime.html. It's a good way to catch subtle bugs that otherwise wouldn't occur because of the values chosen.
To me, this is much easier to understand as well.
# Setup
start = Timex.now()
end = Timex.shift(start, hours: 24)
alert = build(:alert, active_period: [{start, end}]
time = Faker.DateTime.between(start, end)
# Exercise/Verify
assert Alerts.active_for_day?(alert, time)
| @doc """ | ||
| Returns a list of alerts that satisfy the following criteria: | ||
| - They are for one of the subway or trolley lines (including Mattapan), and | ||
| - They are either currently active, or will be later today |
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We could make this more straightforward by saying that the alert is active today... if it is currently active, it will necessarily be active today.
Summary of changes
This adds a
Dotcom.SystemStatusmodule, as well asDotcom.SystemStatus.Alerts, which combined will retrieve a list of all alerts that are either active now, or will become active later today (or whatever day is passed in asnow).This also adds a live view that I was using to test this out. I see that live view morphing into one that previews the system status widget as we get closer to done on this project.
Some questions that I'd be interested in noodling on:
Dotcom.SystemStatus.Alertsthe right place for that filtering logic, or would it make more sense for some or all of that to live in theAlertsnamespace?Asana Ticket: System Status | Add ability to get all future alerts for the day