Fix an unreachable with/else code path

lib/nerves_hub/devices/metrics.ex

@@ -179,7 +179,12 @@ defmodule NervesHub.Devices.Metrics do
         |> Map.merge(%{inserted_at: {:placeholder, :now}})
       end)
 
-    Repo.insert_all(DeviceMetric, entries, placeholders: %{now: DateTime.utc_now()})
+    results = Repo.insert_all(DeviceMetric, entries, placeholders: %{now: DateTime.utc_now()})
+
+    case results do
+      {0, _} -> :error
+      {count, _} -> {:ok, count}
+    end
   end
 
   @doc """

lib/nerves_hub_web/channels/device_channel.ex

@@ -423,16 +423,16 @@ defmodule NervesHubWeb.DeviceChannel do
 
     with {:health_report, {:ok, _}} <-
            {:health_report, Devices.save_device_health(device_health)},
-         {:metrics_report, {_, _}} <-
+         {:metrics_report, {:ok, _}} <-
            {:metrics_report, Metrics.save_metrics(socket.assigns.device.id, metrics)} do
       device_internal_broadcast!(socket, socket.assigns.device, "health_check_report", %{})
     else
       {:health_report, {:error, err}} ->
         Logger.warning("Failed to save health check data: #{inspect(err)}")
         log_to_sentry(socket.assigns.device, "[DeviceChannel] Failed to save health check data.")
 
-      {:metrics_report, {:error, err}} ->
-        Logger.warning("Failed to save metrics: #{inspect(err)}")
+      {:metrics_report, :error} ->
+        Logger.warning("Failed to save metrics")
         log_to_sentry(socket.assigns.device, "[DeviceChannel] Failed to save metrics.")
     end
 

test/nerves_hub/device_metrics_test.exs

@@ -46,7 +46,7 @@ defmodule NervesHub.DeviceMetricsTest do
         "used_percent" => 2
       }
 
-      assert {7, nil} = Metrics.save_metrics(device.id, metrics)
+      assert {:ok, 7} = Metrics.save_metrics(device.id, metrics)
     end
   end
 

test/nerves_hub_web/live/devices/health_test.exs

@@ -37,7 +37,7 @@ defmodule NervesHubWeb.Devices.HealthTest do
       "used_percent" => 2
     }
 
-    assert {7, nil} = Metrics.save_metrics(device.id, metrics)
+    assert {:ok, 7} = Metrics.save_metrics(device.id, metrics)
 
     conn
     |> visit("/org/#{org.name}/#{product.name}/devices/#{device.identifier}/health")

test/nerves_hub_web/live/devices/show_test.exs

@@ -250,7 +250,7 @@ defmodule NervesHubWeb.Live.Devices.ShowTest do
         "used_percent" => 60
       }
 
-      assert {7, nil} = Metrics.save_metrics(device.id, metrics)
+      assert {:ok, 7} = Metrics.save_metrics(device.id, metrics)
 
       conn
       |> visit("/org/#{org.name}/#{product.name}/devices/#{device.identifier}")
@@ -279,7 +279,7 @@ defmodule NervesHubWeb.Live.Devices.ShowTest do
         "used_percent" => 60
       }
 
-      assert {6, nil} = Metrics.save_metrics(device.id, metrics)
+      assert {:ok, 6} = Metrics.save_metrics(device.id, metrics)
 
       conn
       |> visit("/org/#{org.name}/#{product.name}/devices/#{device.identifier}")