Refactor image upload handling in PostController

- Simplified the image upload logic using a `with` statement for better readability.
- Updated error handling to return a 404 response when the post is not found, instead of a 400 response.
- Added a test case to verify that a 404 response is returned when attempting to upload an image for a non-existent post.

Author: ammbot

lib/literature/controllers/post_controller.ex

@@ -2,27 +2,29 @@ defmodule Literature.PostController do
   use Literature.Web, :controller
 
   def upload_image(conn, %{"image" => image} = params) do
-    params
-    |> get_post()
-    |> Literature.update_post(%{"upload_image" => rename_filename(image)})
-    |> case do
-      {:ok, post} ->
+    with %Literature.Post{} = post <- get_post(params),
+         {:ok, post} <- Literature.update_post(post, %{"upload_image" => rename_filename(image)}) do
+      conn
+      |> put_resp_content_type("application/json")
+      |> send_resp(
+        200,
+        Jason.encode!(%{
+          success: 1,
+          file: %{
+            url: literature_image_url(post, :upload_image)
+          }
+        })
+      )
+    else
+      {:error, %Ecto.Changeset{}} ->
         conn
         |> put_resp_content_type("application/json")
-        |> send_resp(
-          200,
-          Jason.encode!(%{
-            success: 1,
-            file: %{
-              url: literature_image_url(post, :upload_image)
-            }
-          })
-        )
+        |> send_resp(400, Jason.encode!(%{success: 0}))
 
-      {:error, %Ecto.Changeset{}} ->
+      nil ->
         conn
         |> put_resp_content_type("application/json")
-        |> send_resp(400, Jason.encode!(%{success: 0}))
+        |> send_resp(404, Jason.encode!(%{success: 0, error: "Post not found"}))
     end
   end
 

test/literature/controllers/post_controller_test.exs

@@ -60,4 +60,28 @@ defmodule Literature.PostControllerTest do
              "success" => 1
            }
   end
+
+  test "upload image returns 404 when post does not exist",
+       %{conn: conn, publication: publication} do
+    params = %{image: file_upload_image()}
+
+    conn =
+      post(
+        conn,
+        Routes.literature_dashboard_path(
+          conn,
+          :upload_image,
+          publication.slug,
+          "non-existent-slug",
+          [
+            "upload-image"
+          ]
+        ),
+        params
+      )
+
+    response = json_response(conn, 404)
+
+    assert response == %{"success" => 0, "error" => "Post not found"}
+  end
 end