chore: upgrade Elixir, Erlang, Phoenix

.tool-versions

@@ -1,3 +1,3 @@
 nodejs 24.5.0
-erlang 28.0.2
-elixir 1.18.4-otp-28
+erlang 28.2
+elixir 1.19.4-otp-28

config/deps/phoenix.exs

@@ -4,11 +4,6 @@ config :phoenix, :gzippable_exts, ~w(.txt .html .js .css .svg)
 config :phoenix, :json_library, Poison
 
 if config_env() == :prod do
-  config :dotcom, :websocket_check_origin, [
-    "https://*.mbta.com",
-    "https://*.mbtace.com"
-  ]
-
   config :dotcom,
     dev_server?: false
 

config/runtime.exs

@@ -196,6 +196,7 @@ config :dotcom, DotcomWeb.ViewHelpers,
   google_tag_manager_auth: System.get_env("GOOGLE_TAG_MANAGER_AUTH"),
   google_tag_manager_preview: System.get_env("GOOGLE_TAG_MANAGER_PREVIEW")
 
+config :dotcom, allow_indexing: System.get_env("ALLOW_INDEXING") == "true"
 config :dotcom, google_api_key: System.get_env("GOOGLE_API_KEY")
 
 config :recaptcha,

deploy/dotcom/dev/Dockerfile

@@ -1,4 +1,4 @@
-FROM hexpm/elixir:1.18.4-erlang-28.0.2-debian-trixie-20250811-slim
+FROM hexpm/elixir:1.19.4-erlang-28.2-debian-trixie-20251229-slim
 
 RUN apt-get update && apt-get install -y curl git make build-essential inotify-tools
 RUN curl -fsSL https://deb.nodesource.com/setup_18.x | bash -

deploy/dotcom/prod/Dockerfile

@@ -1,4 +1,4 @@
-FROM hexpm/elixir:1.18.4-erlang-28.0.2-alpine-3.22.1 AS builder
+FROM hexpm/elixir:1.19.4-erlang-28.2-alpine-3.23.2 AS builder
 
 # ENVS AND ARGS
 ENV LANG="C.UTF-8" MIX_ENV="prod"
@@ -37,7 +37,7 @@ RUN mix compile
 RUN mix phx.digest
 RUN mix release
 
-FROM hexpm/elixir:1.18.4-erlang-28.0.2-alpine-3.22.1
+FROM hexpm/elixir:1.19.4-erlang-28.2-alpine-3.23.2
 
 ENV PORT=4000 MIX_ENV="prod" PHX_SERVER=true TERM=xterm LANG="C.UTF-8" REPLACE_OS_VARS=true
 

lib/alerts/alert.ex

@@ -180,8 +180,8 @@ defmodule Alerts.Alert do
   defp build_struct(keywords), do: struct!(__MODULE__, keywords)
 
   @spec ensure_entity_set(map) :: t()
-  defp ensure_entity_set(alert) do
-    %__MODULE__{alert | informed_entity: InformedEntitySet.new(alert.informed_entity)}
+  defp ensure_entity_set(%__MODULE__{} = alert) do
+    %{alert | informed_entity: InformedEntitySet.new(alert.informed_entity)}
   end
 
   @spec all_types :: [effect]
@@ -333,13 +333,13 @@ defmodule Alerts.Alert do
 end
 
 defimpl Poison.Encoder, for: Alerts.Alert do
-  def encode(%Alerts.Alert{active_period: active_period_pairs} = alert, options) do
-    active_period = Enum.map(active_period_pairs, &alert_active_period/1)
+  def encode(%Alerts.Alert{} = alert, options) do
+    alert =
+      Map.update!(alert, :active_period, fn active_period_pairs ->
+        Enum.map(active_period_pairs, &alert_active_period/1)
+      end)
 
-    Poison.Encoder.Map.encode(
-      %{alert | active_period: active_period},
-      options
-    )
+    Poison.Encoder.Map.encode(alert, options)
   end
 
   @spec alert_active_period(Alerts.Alert.period_pair()) :: [nil | binary]

lib/dotcom/alerts/subway/disruptions.ex

@@ -60,11 +60,11 @@ defmodule Dotcom.Alerts.Subway.Disruptions do
   # result is then two alerts, both equivalent to the alert passed in,
   # except that one has a single active period of {Sun, Tue}, and the
   # other has a single active period of {Thu, Fri}.
-  defp split_by_discontiguous_active_periods(alert) do
+  defp split_by_discontiguous_active_periods(%Alerts.Alert{} = alert) do
     alert.active_period
     |> combine_contiguous_active_periods()
     |> Enum.map(fn active_period ->
-      %Alerts.Alert{alert | active_period: [active_period]}
+      %{alert | active_period: [active_period]}
     end)
   end
 

lib/dotcom/application.ex

@@ -10,20 +10,8 @@ defmodule Dotcom.Application do
 
   # See http://elixir-lang.org/docs/stable/elixir/Application.html
   # for more information on OTP Applications
+  @impl Application
   def start(_type, _args) do
-    Application.put_env(
-      :dotcom,
-      :allow_indexing,
-      DotcomWeb.ControllerHelpers.environment_allows_indexing?()
-    )
-
-    # hack to pull the STATIC_SCHEME variable out of the environment
-    Application.put_env(
-      :dotcom,
-      DotcomWeb.Endpoint,
-      update_static_url(Application.get_env(:dotcom, DotcomWeb.Endpoint))
-    )
-
     children =
       [
         {Application.get_env(:dotcom, :cache, Dotcom.Cache.Multilevel), []},
@@ -61,12 +49,10 @@ defmodule Dotcom.Application do
         [
           Routes.Supervisor,
           Predictions.Supervisor,
-          {Phoenix.PubSub, name: Dotcom.PubSub},
           Alerts.BusStopChangeSupervisor,
-          Alerts.CacheSupervisor
-        ] ++
-        [
-          {DotcomWeb.Endpoint, name: DotcomWeb.Endpoint}
+          Alerts.CacheSupervisor,
+          {Phoenix.PubSub, name: Dotcom.PubSub},
+          DotcomWeb.Endpoint
         ] ++
         if Application.get_env(:dotcom, :env) != :test do
           [
@@ -85,24 +71,9 @@ defmodule Dotcom.Application do
 
   # Tell Phoenix to update the endpoint configuration
   # whenever the application is updated.
+  @impl Application
   def config_change(changed, _new, removed) do
     DotcomWeb.Endpoint.config_change(changed, removed)
     :ok
   end
-
-  defp update_static_url([{:static_url, static_url_parts} | rest]) do
-    static_url_parts = Keyword.update(static_url_parts, :scheme, nil, &update_static_url_scheme/1)
-    [{:static_url, static_url_parts} | update_static_url(rest)]
-  end
-
-  defp update_static_url([first | rest]) do
-    [first | update_static_url(rest)]
-  end
-
-  defp update_static_url([]) do
-    []
-  end
-
-  defp update_static_url_scheme({:system, env_var}), do: System.get_env(env_var)
-  defp update_static_url_scheme(scheme), do: scheme
 end

lib/dotcom/trip_plan/open_street_map_reconciler.ex

@@ -58,8 +58,8 @@ defmodule Dotcom.TripPlan.OpenStreetMapReconciler do
   """
   @spec reconcile(InputForm.t()) :: InputForm.t()
   @spec reconcile(arg) :: arg when arg: var
-  def reconcile(%{from: from, to: to} = form) do
-    %InputForm{form | from: reconcile_location(from), to: reconcile_location(to)}
+  def reconcile(%InputForm{from: from, to: to} = form) do
+    %{form | from: reconcile_location(from), to: reconcile_location(to)}
   end
 
   def reconcile(form), do: form

lib/dotcom_web/controllers/cache_controller.ex

@@ -180,7 +180,7 @@ defmodule DotcomWeb.CacheController do
           }
         end)
 
-      assigns = assign(assigns, links: links)
+      assigns = Phoenix.Controller.assign(assigns, links: links)
 
       ~H"""
       <ul>

lib/dotcom_web/controllers/helpers.ex

@@ -158,11 +158,6 @@ defmodule DotcomWeb.ControllerHelpers do
     end
   end
 
-  @spec environment_allows_indexing?() :: boolean()
-  def environment_allows_indexing? do
-    System.get_env("ALLOW_INDEXING") == "true"
-  end
-
   @spec filter_alerts_by_direction([Alert.t()], boolean, String.t() | number | nil) :: [Alert.t()]
   defp filter_alerts_by_direction(alerts, false, _), do: alerts
   defp filter_alerts_by_direction(alerts, true, nil), do: alerts

lib/dotcom_web/controllers/schedule/line/helpers.ex

@@ -293,9 +293,9 @@ defmodule DotcomWeb.ScheduleController.Line.Helpers do
 
   @spec do_nil_out_shared_stop_branches([RouteStop.t()], MapSet.t(Stop.id_t())) :: [RouteStop.t()]
   defp do_nil_out_shared_stop_branches(route_pattern_group, shared_ids) do
-    Enum.map(route_pattern_group, fn route_stop ->
+    Enum.map(route_pattern_group, fn %RouteStop{} = route_stop ->
       if MapSet.member?(shared_ids, route_stop.id) do
-        %RouteStop{
+        %{
           route_stop
           | branch: nil
         }

lib/dotcom_web/endpoint.ex

@@ -9,13 +9,7 @@ defmodule DotcomWeb.Endpoint do
                    signing_salt: "TInvb4GN",
                    secure: true
 
-  socket(
-    "/socket",
-    DotcomWeb.UserSocket,
-    websocket: [check_origin: Application.compile_env(:dotcom, :websocket_check_origin, false)],
-    longpoll: [check_origin: Application.compile_env(:dotcom, :websocket_check_origin, false)]
-  )
-
+  socket("/socket", DotcomWeb.UserSocket)
   socket("/live", Phoenix.LiveView.Socket, websocket: [connect_info: [session: @session_options]])
 
   # Serve at "/" the static files from "priv/static" directory.

lib/location_service/address.ex

@@ -46,7 +46,7 @@ defmodule LocationService.Address do
   @spec parse_label(String.t(), %__MODULE__{}) :: %__MODULE__{}
   defp parse_label("", address), do: address
 
-  defp parse_label(label, address) do
+  defp parse_label(label, %__MODULE__{} = address) do
     %AddressUS.Address{
       street: %AddressUS.Street{
         name: street_name,
@@ -62,7 +62,7 @@ defmodule LocationService.Address do
       |> String.trim()
       |> with_place_name(label)
 
-    %__MODULE__{address | street_address: street_address, municipality: city, state: state}
+    %{address | street_address: street_address, municipality: city, state: state}
   rescue
     _ ->
       # Remove first section of label, try again!

lib/predictions/repo.ex

@@ -134,8 +134,8 @@ defmodule Predictions.Repo do
 
   defp has_departure_time?(
          {_id, _trip_id, _stop_id, _route_id, _direction_id, _arrival, departure, _time,
-          _stop_sequence, _schedule_relationship, _track, _status, _departing?,
-          _vehicle_id} = _prediction
+          _stop_sequence, _schedule_relationship, _track, _status, _departing?, _vehicle_id} =
+           _prediction
        ) do
     departure != nil
   end

lib/stops/route_stop.ex

@@ -349,8 +349,8 @@ defmodule Stops.RouteStop do
     {first_last, first_body} = List.pop_at(first, -1)
 
     first_body ++
-      [%RouteStop{first_last | terminus?: false}] ++
-      (second |> tl() |> Enum.map(&%RouteStop{&1 | branch: branch(first)}))
+      [%{first_last | terminus?: false}] ++
+      (second |> tl() |> Enum.map(&%{&1 | branch: branch(first)}))
   end
 
   @spec branch([RouteStop.t()]) :: RouteStop.branch_name_t()

mix.exs

@@ -15,12 +15,6 @@ defmodule DotCom.Mixfile do
       # used by `mix app.start` to start the application and children in permanent mode, which guarantees the node will shut down if the application terminates (typically because its root supervisor has terminated).
       start_permanent: Mix.env() == :prod,
       test_coverage: [tool: ExCoveralls],
-      preferred_cli_env: [
-        coveralls: :test,
-        "coveralls.html": :test,
-        "gettext.extract": :prod,
-        "gettext.translate": :prod
-      ],
       dialyzer: [
         plt_add_apps: [:mix, :phoenix_live_reload, :mbta_metro],
         flags: [:unmatched_returns]
@@ -36,6 +30,17 @@ defmodule DotCom.Mixfile do
     ]
   end
 
+  def cli do
+    [
+      preferred_envs: [
+        coveralls: :test,
+        "coveralls.html": :test,
+        "gettext.extract": :prod,
+        "gettext.translate": :prod
+      ]
+    ]
+  end
+
   # Specifies which paths to compile per environment.
   defp elixirc_paths(:dev),
     do: [
@@ -60,7 +65,7 @@ defmodule DotCom.Mixfile do
       if Mix.env() == :prod do
         [:sasl | extra_apps]
       else
-        extra_apps
+        [:wx, :observer | extra_apps]
       end
 
     [
@@ -94,7 +99,7 @@ defmodule DotCom.Mixfile do
       {:csv, "3.2.2"},
       {:cva, "0.2.2"},
       {:decorator, "1.4.0"},
-      {:dialyxir, "1.4.6", [only: [:dev, :test], runtime: false]},
+      {:dialyxir, "1.4.7", [only: [:dev, :test], runtime: false]},
       {:diskusage_logger, "0.2.0"},
       {:ecto, "3.13.4"},
       {:eextoheex, git: "https://github.com/Multiverse-io/eextoheex", only: [:dev, :test]},
@@ -135,7 +140,7 @@ defmodule DotCom.Mixfile do
         [github: "mbta/open_trip_planner_client", tag: "v0.17.1"]
       },
       {:parallel_stream, "1.1.0"},
-      {:phoenix, "1.8.1", override: true},
+      {:phoenix, "1.8.3", override: true},
       {:phoenix_ecto, "4.6.5"},
       {:phoenix_html_helpers, "1.0.1"},
       {:phoenix_live_dashboard, "0.8.7"},