Add tests for renderers

Author: browniebroke

drf_excel/renderers.py

@@ -56,12 +56,12 @@ def render(self, data, accepted_media_type=None, renderer_context=None):
         """
         Render `data` into XLSX workbook, returning a workbook.
         """
-        if not self._check_validation_data(data):
-            return json.dumps(data)
-
         if data is None:
             return bytes()
 
+        if not self._check_validation_data(data):
+            return json.dumps(data)
+
         wb = Workbook()
         self.ws = wb.active
 

tests/conftest.py

@@ -1,4 +1,8 @@
+import io
+from typing import Union, Callable
+
 import pytest
+from openpyxl.reader.excel import load_workbook
 from openpyxl.workbook import Workbook
 from openpyxl.worksheet.worksheet import Worksheet
 
@@ -11,3 +15,12 @@ def workbook() -> Workbook:
 @pytest.fixture
 def worksheet(workbook: Workbook) -> Worksheet:
     return Worksheet(workbook)
+
+
+@pytest.fixture
+def workbook_reader() -> Callable[[Union[bytes, str]], Workbook]:
+    def reader_func(buffer: Union[bytes, str]) -> Workbook:
+        io_buffer = io.BytesIO(buffer)
+        return load_workbook(io_buffer, read_only=True)
+
+    return reader_func

tests/test_renderers.py

@@ -0,0 +1,50 @@
+from PIL import Image
+from rest_framework import serializers
+from rest_framework.generics import GenericAPIView
+from rest_framework.response import Response
+
+from drf_excel.renderers import XLSXRenderer
+
+
+class MySerializer(serializers.Serializer):
+    title = serializers.CharField()
+
+
+class MyBaseView(GenericAPIView):
+    serializer_class = MySerializer
+
+    def retrieve(self, request, *args, **kwargs):
+        return Response({"title": "example"})
+
+
+class TestXLSXRenderer:
+    renderer = XLSXRenderer()
+
+    def test_validation_error(self):
+        assert self.renderer.render({"detail": "invalid"}) == '{"detail": "invalid"}'
+
+    def test_none(self):
+        assert self.renderer.render(None) == b""
+
+    def test_with_header_attribute(self, tmp_path, workbook_reader):
+        image_path = tmp_path / "image.png"
+        with Image.new(mode="RGB", size=(100, 100), color="blue") as img:
+            img.save(image_path, format="png")
+
+        class MyView(MyBaseView):
+            header = {
+                "use_header": True,
+                "header_title": "My Header",
+                "tab_title": "My Tab",
+                "img": str(image_path),
+                "style": {"font": {"name": "Arial"}},
+            }
+
+        result = self.renderer.render({}, renderer_context={"view": MyView})
+        wb = workbook_reader(result)
+        sheet = wb.worksheets[0]
+        rows = list(sheet.rows)
+        assert len(rows) == 1
+        row0_col0 = rows[0][0]
+        assert row0_col0.value == "My Header"
+        assert row0_col0.font.name == "Arial"

tests/test_viewset_mixin.py

@@ -1,14 +1,11 @@
-import io
 import datetime as dt
 
 import pytest
-from openpyxl.reader.excel import load_workbook
 from rest_framework.test import APIClient
 from time_machine import TimeMachineFixture
 
 from tests.testapp.models import ExampleModel, AllFieldsModel, Tag
 
-
 pytestmark = pytest.mark.django_db
 
 
@@ -17,7 +14,7 @@ def api_client():
     return APIClient()
 
 
-def test_simple_viewset_model(api_client):
+def test_simple_viewset_model(api_client, workbook_reader):
     ExampleModel.objects.create(title="test 1", description="This is a test")
     ExampleModel.objects.create(title="test 2", description="Another test")
     ExampleModel.objects.create(title="test 3", description="Testing this out")
@@ -33,11 +30,10 @@ def test_simple_viewset_model(api_client):
         response.headers["content-disposition"] == "attachment; filename=my_export.xlsx"
     )
 
-    workbook_buffer = io.BytesIO(response.content)
-    workbook = load_workbook(workbook_buffer, read_only=True)
+    wb = workbook_reader(response.content)
 
-    assert len(workbook.worksheets) == 1
-    sheet = workbook.worksheets[0]
+    assert len(wb.worksheets) == 1
+    sheet = wb.worksheets[0]
     rows = list(sheet.rows)
     assert len(rows) == 4
     r0, r1, r2, r3 = rows
@@ -59,7 +55,9 @@ def test_simple_viewset_model(api_client):
     assert r3[1].value == "Testing this out"
 
 
-def test_all_fields_viewset(api_client, time_machine: TimeMachineFixture):
+def test_all_fields_viewset(
+    api_client, time_machine: TimeMachineFixture, workbook_reader
+):
     time_machine.move_to(dt.datetime(2023, 9, 10, 15, 44, 37))
     instance = AllFieldsModel.objects.create(title="Hello", age=36, is_active=True)
     instance.tags.set(
@@ -71,9 +69,8 @@ def test_all_fields_viewset(api_client, time_machine: TimeMachineFixture):
     response = api_client.get("/all-fields/")
     assert response.status_code == 200
 
-    workbook_buffer = io.BytesIO(response.content)
-    workbook = load_workbook(workbook_buffer, read_only=True)
-    sheet = workbook.worksheets[0]
+    wb = workbook_reader(response.content)
+    sheet = wb.worksheets[0]
     rows = list(sheet.rows)
     assert len(rows) == 2
     r0, r1 = rows

tox.ini

@@ -13,6 +13,7 @@ deps =
 
     djangorestframework
     openpyxl
+    Pillow
 
     pytest
     pytest-django