Improve error handling for web upload of bad CSV

todo/operations/csv_importer.py

@@ -54,10 +54,10 @@ class CSVImporter:
             "Priority",
         ]
         if header != expected:
-            self.results.get("summaries").append(
+            self.errors.append(
                 f"Inbound data does not have expected columns.\nShould be: {expected}"
             )
-            return self.results
+            return
 
         for row in csv_reader:
             self.line_count += 1

todo/views/import_csv.py

@@ -24,6 +24,12 @@ def import_csv(request) -> HttpResponse:
 
         importer = CSVImporter()
         results = importer.upsert(filepath)
+
+        ctx["results"] = None
+        if results:
             ctx["results"] = results
+        else:
+            messages.error(request, "Could not parse provided CSV file.")
+            return redirect(reverse("todo:import_csv"))
 
     return render(request, "todo/import_csv.html", context=ctx)