test: expand tests for file transfer

- Expanded test coverage for the file transfer feature
- Refactored and improved code to address bugs identified through
the new tests

Signed-off-by: ArnelaL <arnela.lisic@secomind.com>

Author: ArnelaL

backend/lib/edgehog/files/file/changes/handle_file_upload.ex

@@ -71,16 +71,15 @@ defmodule Edgehog.Files.File.Changes.HandleFileUpload do
     tasks = Enum.map(uploads, fn {_encoding, task} -> task end)
     results = Task.yield_many(tasks, timeout)
 
-    {changeset, failed?} =
+    {changeset, failed?, errors} =
       uploads
       |> Enum.zip(results)
-      |> Enum.reduce({changeset, false}, &reduce_results/2)
+      |> Enum.reduce({changeset, false, []}, &reduce_results/2)
 
     if failed? do
-      Ash.Changeset.add_error(changeset,
-        field: :file,
-        message: "One or more file uploads failed"
-      )
+      Enum.reduce(errors, changeset, fn error, acc ->
+        Ash.Changeset.add_error(acc, error)
+      end)
     else
       changeset
     end
@@ -161,36 +160,64 @@ defmodule Edgehog.Files.File.Changes.HandleFileUpload do
 
   defp ceil_div(dividend, divisor), do: div(dividend + divisor - 1, divisor)
 
-  defp reduce_results({{_encoding, _task}, {_task_pid, {:ok, result}}}, {acc_changeset, failed?}) do
+  defp reduce_results(
+         {{_encoding, _task}, {_pid, {:ok, result}}},
+         {acc, failed?, errors}
+       ) do
     case result do
-      {:ok, changeset} -> {merge_changesets(acc_changeset, changeset), failed?}
-      {:error, changeset} -> {merge_changesets(acc_changeset, changeset), true}
+      {:ok, cs} ->
+        {merge_changesets(acc, cs), failed?, errors}
+
+      {:error, cs} ->
+        {merge_changesets(acc, cs), true, acc_errors(errors, cs)}
     end
   end
 
-  defp reduce_results({{encoding, task}, {_task_pid, nil}}, {acc_changeset, _failed?}) do
-    Logger.error("Upload task timed out for #{encoding || "base"} encoding")
+  defp reduce_results(
+         {{encoding, task}, {_pid, nil}},
+         {acc, _failed?, errors}
+       ) do
     _ = Task.shutdown(task, :brutal_kill)
 
-    {Ash.Changeset.add_error(acc_changeset,
-       field: :file,
-       message: "Upload process timed out"
-     ), true}
+    cs =
+      Ash.Changeset.add_error(acc,
+        field: :file,
+        message: "Upload process timed out (#{encoding || "base"})"
+      )
+
+    {cs, true, acc_errors(errors, cs)}
   end
 
   defp reduce_results(
-         {{encoding, _task}, {_task_pid, {:exit, reason}}},
-         {acc_changeset, _failed?}
+         {{encoding, _task}, {_pid, {:exit, reason}}},
+         {acc, _failed?, errors}
        ) do
-    Logger.error("Upload task crashed for #{encoding || "base"} encoding: #{inspect(reason)}")
+    Logger.error("Upload task crashed for #{encoding || "base"}: #{inspect(reason)}")
+
+    error = %{
+      encoding: encoding || :base,
+      type: :crash,
+      message: "Upload process crashed",
+      reason: reason
+    }
 
-    {Ash.Changeset.add_error(acc_changeset, field: :file, message: "Upload process failed"), true}
+    {acc, true, [error | errors]}
   end
 
-  defp reduce_results({{encoding, _task}, {_task_result, reason}}, {acc_changeset, _failed?}) do
-    Logger.error("Upload task failed for #{encoding || "base"} encoding: #{inspect(reason)}")
+  defp reduce_results(
+         {{encoding, _task}, {_result, reason}},
+         {acc, _failed?, errors}
+       ) do
+    Logger.error("Upload task failed for #{encoding || "base"}: #{inspect(reason)}")
+
+    error = %{
+      encoding: encoding || :base,
+      type: :error,
+      message: "Upload process failed",
+      reason: reason
+    }
 
-    {Ash.Changeset.add_error(acc_changeset, field: :file, message: "Upload process failed"), true}
+    {acc, true, [error | errors]}
   end
 
   defp merge_changesets(acc_changeset, new_changeset) do
@@ -199,6 +226,10 @@ defmodule Edgehog.Files.File.Changes.HandleFileUpload do
     |> Map.put(:context, Map.merge(acc_changeset.context, new_changeset.context))
   end
 
+  defp acc_errors(errors, changeset) do
+    changeset.errors ++ errors
+  end
+
   defp maybe_delete_temporary_upload(%Plug.Upload{path: original_path}, %Plug.Upload{path: path})
        when original_path != path do
     _ = File.rm(path)
@@ -210,13 +241,9 @@ defmodule Edgehog.Files.File.Changes.HandleFileUpload do
   # If we've uploaded the file and the transaction resulted in an error, we do our
   # best to clean up
   defp cleanup_on_error(changeset, {:error, _} = result) do
-    case Ash.Changeset.apply_attributes(changeset) do
-      {:ok, file_record} ->
-        do_cleanup(file_record, changeset.context)
+    file_record = Map.merge(changeset.data, changeset.attributes)
 
-      {:error, reason} ->
-        Logger.warning("Failed to apply attributes for cleanup: #{inspect(reason)}")
-    end
+    do_cleanup(file_record, changeset.context)
 
     result
   end