Fix credo warnings and software design suggestions

Replace expensive length/1 comparisons with direct list comparisons or Enum.empty?/1 checks (13 instances in source code and tests). Add module aliases for Phoenix.HTML.Form and Towerops.Accounts.Scope to reduce nested module references.

Changes:
- Replace length(list) > 0 with list != [] or refute Enum.empty?(list)
- Add Phoenix.HTML.Form alias in CoreComponents
- Add Towerops.Accounts.Scope alias in ConnCase test helper

This eliminates all credo warnings and software design suggestions.

lib/towerops/snmp/poller_worker.ex

@@ -55,7 +55,7 @@ defmodule Towerops.Snmp.PollerWorker do
       # Get the device to check if it has sensors/interfaces
       device = Snmp.get_device_with_associations(equipment_id)
 
-      if device && (length(device.sensors) > 0 || length(device.interfaces) > 0) do
+      if device && (device.sensors != [] || device.interfaces != []) do
         # Perform immediate poll when starting
         send(self(), :poll_data)
       end
@@ -416,7 +416,7 @@ defmodule Towerops.Snmp.PollerWorker do
       end
 
     # If there are changes, broadcast events and update interface
-    if length(changes) > 0 do
+    if changes != [] do
       # Broadcast all events via PubSub
       Enum.each(changes, fn {:event, event_attrs} ->
         Phoenix.PubSub.broadcast(

lib/towerops/snmp/profiles/mikrotik.ex

@@ -106,12 +106,12 @@ defmodule Towerops.Snmp.Profiles.Mikrotik do
 
     all_sensors = health_sensors ++ resource_sensors ++ entity_sensors
 
-    if length(all_sensors) > 0 do
-      Logger.debug("Discovered #{length(all_sensors)} MikroTik sensors")
-      {:ok, all_sensors}
-    else
+    if all_sensors == [] do
       Logger.warning("No MikroTik sensors found")
       {:ok, []}
+    else
+      Logger.debug("Discovered #{length(all_sensors)} MikroTik sensors")
+      {:ok, all_sensors}
     end
   end
 

lib/towerops/snmp/profiles/net_snmp.ex

@@ -65,12 +65,12 @@ defmodule Towerops.Snmp.Profiles.NetSnmp do
 
     all_sensors = lm_sensors ++ ucd_sensors
 
-    if length(all_sensors) > 0 do
-      {:ok, all_sensors}
-    else
+    if all_sensors == [] do
       # Fall back to standard ENTITY-SENSOR-MIB
       Logger.debug("Net-SNMP specific sensors not available, using standard discovery")
       Base.discover_sensors(client_opts)
+    else
+      {:ok, all_sensors}
     end
   end
 

lib/towerops_web/components/core_components.ex

@@ -25,6 +25,7 @@ defmodule ToweropsWeb.CoreComponents do
   use Phoenix.Component
   use Gettext, backend: ToweropsWeb.Gettext
 
+  alias Phoenix.HTML.Form
   alias Phoenix.HTML.FormField
   alias Phoenix.LiveView.JS
 
@@ -247,7 +248,7 @@ defmodule ToweropsWeb.CoreComponents do
   def input(%{type: "checkbox"} = assigns) do
     assigns =
       assign_new(assigns, :checked, fn ->
-        Phoenix.HTML.Form.normalize_value("checkbox", assigns[:value])
+        Form.normalize_value("checkbox", assigns[:value])
       end)
 
     ~H"""

lib/towerops_web/live/equipment_live/index.ex

@@ -15,7 +15,7 @@ defmodule ToweropsWeb.EquipmentLive.Index do
      socket
      |> assign(:page_title, "Equipment")
      |> assign(:equipment, equipment)
-     |> assign(:has_sites, length(sites) > 0)}
+     |> assign(:has_sites, sites != [])}
   end
 
   @impl true

test/integration/snmp_integration_test.exs

@@ -83,11 +83,11 @@ defmodule Towerops.Integration.SnmpIntegrationTest do
 
       # Discover interfaces
       {:ok, interfaces} = Mikrotik.discover_interfaces(@test_device_opts)
-      assert length(interfaces) > 0
+      refute Enum.empty?(interfaces)
 
       # Discover sensors
       {:ok, sensors} = Mikrotik.discover_sensors(@test_device_opts)
-      assert length(sensors) > 0
+      refute Enum.empty?(sensors)
 
       # Identify device
       device_info = Mikrotik.identify_device(system_info)
@@ -134,7 +134,7 @@ defmodule Towerops.Integration.SnmpIntegrationTest do
       Process.sleep(200)
 
       alerts = Towerops.Alerts.list_equipment_alerts(equipment.id)
-      assert length(alerts) > 0
+      refute Enum.empty?(alerts)
 
       alert = hd(alerts)
       assert alert.alert_type == :equipment_down

test/support/conn_case.ex

@@ -17,6 +17,8 @@ defmodule ToweropsWeb.ConnCase do
 
   use ExUnit.CaseTemplate
 
+  alias Towerops.Accounts.Scope
+
   using do
     quote do
       use ToweropsWeb, :verified_routes
@@ -46,7 +48,7 @@ defmodule ToweropsWeb.ConnCase do
   """
   def register_and_log_in_user(%{conn: conn} = context) do
     user = Towerops.AccountsFixtures.user_fixture()
-    scope = Towerops.Accounts.Scope.for_user(user)
+    scope = Scope.for_user(user)
 
     opts =
       context

test/towerops/monitoring/equipment_monitor_test.exs

@@ -67,7 +67,7 @@ defmodule Towerops.Monitoring.EquipmentMonitorTest do
 
       # Should have created a monitoring check
       checks = Monitoring.list_equipment_checks(equipment.id)
-      assert length(checks) > 0
+      refute Enum.empty?(checks)
     end
   end
 
@@ -131,7 +131,7 @@ defmodule Towerops.Monitoring.EquipmentMonitorTest do
 
       # Should create an alert (no need to sleep since test env doesn't send emails)
       alerts = Alerts.list_equipment_alerts(equipment.id)
-      assert length(alerts) > 0
+      refute Enum.empty?(alerts)
 
       alert = hd(alerts)
       assert alert.alert_type == :equipment_down
@@ -158,7 +158,7 @@ defmodule Towerops.Monitoring.EquipmentMonitorTest do
       # Should create recovery alert
       alerts = Alerts.list_equipment_alerts(equipment.id, 10)
       up_alerts = Enum.filter(alerts, &(&1.alert_type == :equipment_up))
-      assert length(up_alerts) > 0
+      refute Enum.empty?(up_alerts)
     end
 
     test "does not create duplicate down alerts", %{equipment: equipment} do

test/towerops_web/live/equipment_live_test.exs

@@ -134,7 +134,7 @@ defmodule ToweropsWeb.EquipmentLiveTest do
 
       # Verify equipment was created
       equipment_list = Towerops.Equipment.list_organization_equipment(organization.id)
-      assert length(equipment_list) > 0
+      refute Enum.empty?(equipment_list)
 
       new_equipment = Enum.find(equipment_list, &(&1.name == "New Router"))
       assert new_equipment