test: fix Finch name reuse race and silence reconnect log spam

- fake_http_server: stop the Finch supervisor synchronously instead of
  killing the registry, so the name slot is free before the next test
  reuses it; check the supervisor name too so a crashed test can't
  collide with the next start
- capture WSConnection reconnect logs per test module, showing them
  only when a test fails
- unlink contexts before Process.exit(ctx, :kill) — under capture_log
  the kill signal could race the test process's own exit
- silence Logger info chatter in test_helper.exs

Author: gilbertwong96

test/longbridge/connection/session_test.exs

@@ -1,6 +1,11 @@
 defmodule Longbridge.Connection.SessionTest do
   use ExUnit.Case, async: true
 
+  # Refresh-failure tests deliberately exercise the token-refresher
+  # error paths, which log warnings; capture them and show them only
+  # when a test fails.
+  @moduletag capture_log: true
+
   alias Longbridge.Config
   alias Longbridge.Connection.Session
 

test/longbridge/quote_context_test.exs

@@ -1,6 +1,11 @@
 defmodule Longbridge.QuoteContextTest do
   use ExUnit.Case, async: false
 
+  # The fake WS server teardown deliberately kills connections, which
+  # makes WSConnection log reconnect churn; capture it and show it only
+  # when a test fails.
+  @moduletag capture_log: true
+
   alias Longbridge.{Config, Protocol, QuoteContext, WSConnection}
   alias Longbridge.Control.V1, as: Ctrl
   alias Longbridge.Protocol.Header

test/longbridge/trade_context_extra_test.exs

@@ -1,6 +1,11 @@
 defmodule Longbridge.TradeContextExtraTest do
   use ExUnit.Case, async: false
 
+  # Subscribe/unsubscribe tests run a real WS connection against fake
+  # servers and deliberately exercise disconnect paths; capture the
+  # WSConnection logs and show them only when a test fails.
+  @moduletag capture_log: true
+
   import Bitwise
 
   alias Longbridge.{Config, Protocol, TradeContext}
@@ -332,6 +337,7 @@ defmodule Longbridge.TradeContextExtraTest do
       {:ok, ctx} = TradeContext.start_link(config, skip_connection: true)
       Process.sleep(50)
       assert {:ok, nil, nil} = TradeContext.session(ctx)
+      Process.unlink(ctx)
       Process.exit(ctx, :kill)
     end
   end
@@ -425,6 +431,7 @@ defmodule Longbridge.TradeContextExtraTest do
       )
 
       assert_receive :got, 1_000
+      Process.unlink(ctx)
       Process.exit(ctx, :kill)
     end
   end
@@ -443,6 +450,7 @@ defmodule Longbridge.TradeContextExtraTest do
       # that falls into `_ -> :ok`.
       send(ctx, {:longbridge, ctx, {:push, 99, "not-json-at-all"}})
       refute_receive {:default, _}, 500
+      Process.unlink(ctx)
       Process.exit(ctx, :kill)
     end
   end

test/longbridge/trade_context_test.exs

@@ -1,6 +1,11 @@
 defmodule Longbridge.TradeContextTest do
   use ExUnit.Case, async: false
 
+  # Reconnect tests deliberately break sockets and watch the retry
+  # backoff, flooding the output with WSConnection logs; capture them
+  # and show them only when a test fails.
+  @moduletag capture_log: true
+
   alias Longbridge.{Config, TradeContext}
 
   # ── Fake HTTP server ─────────────────────────────────────

test/longbridge/trade_push_test.exs

@@ -3,6 +3,9 @@ defmodule Longbridge.TradePushTest do
 
   alias Longbridge.{Config, TradeContext}
 
+  # Push tests run a real WS connection and exercise disconnect paths;
+  # capture the WSConnection logs and show them only on failure.
+  @moduletag capture_log: true
   @moduletag :trade_push
 
   defp encode_notification(notification) do
@@ -53,6 +56,7 @@ defmodule Longbridge.TradePushTest do
       assert event["status"] == "PartiallyFilled"
       assert event["filled_qty"] == "50"
 
+      Process.unlink(ctx)
       Process.exit(ctx, :kill)
     end
 
@@ -86,6 +90,7 @@ defmodule Longbridge.TradePushTest do
       # Should NOT receive any event (empty topic)
       refute_receive {:event, _}, 500
 
+      Process.unlink(ctx)
       Process.exit(ctx, :kill)
     end
 
@@ -134,6 +139,7 @@ defmodule Longbridge.TradePushTest do
       assert event["executed_quantity"] == "200"
       assert event["executed_price"] == "50.5"
 
+      Process.unlink(ctx)
       Process.exit(ctx, :kill)
     end
 
@@ -166,6 +172,7 @@ defmodule Longbridge.TradePushTest do
 
       refute_receive {:event, _}, 500
 
+      Process.unlink(ctx)
       Process.exit(ctx, :kill)
     end
   end

test/longbridge/ws_connection_extra_test.exs

@@ -1,6 +1,11 @@
 defmodule Longbridge.WSConnectionExtraTest do
   use ExUnit.Case, async: false
 
+  # Connect-failure tests deliberately point at dead servers and watch
+  # the reconnect backoff, flooding the output with WSConnection logs;
+  # capture them and show them only when a test fails.
+  @moduletag capture_log: true
+
   alias Longbridge.{Config, Protocol, WSConnection}
   alias Longbridge.Control.V1, as: Ctrl
   alias Longbridge.Protocol.Header

test/longbridge/ws_connection_test.exs

@@ -1,6 +1,11 @@
 defmodule Longbridge.WSConnectionTest do
   use ExUnit.Case, async: false
 
+  # Connection tests deliberately drop sockets and time out auth to
+  # exercise reconnect paths; capture the WSConnection logs and show
+  # them only when a test fails.
+  @moduletag capture_log: true
+
   alias Longbridge.{Config, Protocol, WSConnection}
   alias Longbridge.Control.V1, as: Ctrl
   alias Longbridge.Protocol.Header

test/support/fake_http_server.ex

@@ -76,13 +76,20 @@ defmodule Longbridge.TestSupport.FakeHTTPServer do
 
     try do
       handler.(conn)
-    rescue
-      exception ->
+    catch
+      kind, reason ->
+        exception = Exception.normalize(kind, reason, __STACKTRACE__)
         HandlerStore.set(store, {:error, exception, __STACKTRACE__})
         Conn.send_resp(conn, 500, "test handler crashed")
     end
   end
 
+  # Pre-created Finch names, one per concurrently-running test server.
+  # Tests run sequentially, so this pool never runs dry; the whereis
+  # check reuses a slot as soon as the previous server's Finch is gone.
+  @finch_names for i <- 0..31, do: :"longbridge_test_finch_#{i}"
+  @finch_supervisor_names for name <- @finch_names, into: %{}, do: {name, :"#{name}.Supervisor"}
+
   @doc """
   Starts a server AND a fresh Finch pool whose name is stored in the
   test process's dictionary so `HTTPClient` auto-picks it up.
@@ -94,8 +101,7 @@ defmodule Longbridge.TestSupport.FakeHTTPServer do
           finch: atom()
         }
   def start_with_finch(handler) when is_function(handler, 1) do
-    # credo:disable-for-next-line Credo.Check.Warning.UnsafeToAtom
-    finch_name = String.to_atom("longbridge_test_finch_#{System.unique_integer([:positive])}")
+    finch_name = finch_name()
 
     {:ok, _pid} =
       Finch.start_link(
@@ -126,8 +132,14 @@ defmodule Longbridge.TestSupport.FakeHTTPServer do
     if Process.alive?(sup), do: Supervisor.stop(sup, :shutdown)
     if Process.alive?(store), do: Agent.stop(store)
 
-    if finch_pid = Process.whereis(finch_name),
-      do: Process.exit(finch_pid, :kill)
+    # Unlink before stopping: the Finch supervisor was started from the
+    # test process, and a linked caller dies with the supervisor's
+    # :shutdown exit signal. Stopping synchronously guarantees the name
+    # slot is free before the next test reuses it.
+    if finch_sup = Process.whereis(@finch_supervisor_names[finch_name]) do
+      Process.unlink(finch_sup)
+      Supervisor.stop(finch_sup, :shutdown)
+    end
 
     :ok
   end
@@ -193,6 +205,16 @@ defmodule Longbridge.TestSupport.FakeHTTPServer do
 
   # ── Internal ──────────────────────────────────────────────
 
+  defp finch_name do
+    Enum.find(@finch_names, fn name ->
+      # The registry (registered under `name`) and the supervisor
+      # (registered under `name.Supervisor`) are the last processes to
+      # unregister during teardown; check both so a crashed test that
+      # skipped `stop_with_finch/1` doesn't collide with the next start.
+      is_nil(Process.whereis(name)) and is_nil(Process.whereis(@finch_supervisor_names[name]))
+    end) || raise "all #{length(@finch_names)} fake Finch names are in use"
+  end
+
   defp free_port do
     {:ok, listen} = :gen_tcp.listen(0, [:binary, active: false, reuseaddr: true])
     {:ok, port} = :inet.port(listen)

test/test_helper.exs

@@ -1 +1,7 @@
+# The WS reconnect and token-refresh failure-path tests deliberately
+# trigger library log lines, flooding `mix test` output. Silence the
+# info/debug chatter here (capture_log-based tests still work because
+# warning messages pass the level check).
+Logger.configure(level: :warning)
+
 ExUnit.start()