remove compatibility code from tests for the case dataclasses module is not available

It was Python 3.6 compat code, and Python 3.6 support is dropped.

tests/test_exporters.py

@@ -4,6 +4,7 @@ import marshal
 import pickle
 import tempfile
 import unittest
+import dataclasses
 from io import BytesIO
 from datetime import datetime
 from warnings import catch_warnings, filterwarnings
@@ -21,31 +22,30 @@ from scrapy.exporters import (
 )
 
 
+def custom_serializer(value):
+    return str(int(value) + 2)
+
+
 class TestItem(Item):
     name = Field()
     age = Field()
 
 
-def custom_serializer(value):
-    return str(int(value) + 2)
-
-
 class CustomFieldItem(Item):
     name = Field()
     age = Field(serializer=custom_serializer)
 
 
-try:
-    from dataclasses import make_dataclass, field
-except ImportError:
-    TestDataClass = None
-    CustomFieldDataclass = None
-else:
-    TestDataClass = make_dataclass("TestDataClass", [("name", str), ("age", int)])
-    CustomFieldDataclass = make_dataclass(
-        "CustomFieldDataclass",
-        [("name", str), ("age", int, field(metadata={"serializer": custom_serializer}))]
-    )
+@dataclasses.dataclass
+class TestDataClass:
+    name: str
+    age: int
+
+
+@dataclasses.dataclass
+class CustomFieldDataclass:
+    name: str
+    age: int = dataclasses.field(metadata={"serializer": custom_serializer})
 
 
 class BaseItemExporterTest(unittest.TestCase):
@@ -54,8 +54,6 @@ class BaseItemExporterTest(unittest.TestCase):
     custom_field_item_class = CustomFieldItem
 
     def setUp(self):
-        if self.item_class is None:
-            raise unittest.SkipTest("item class is None")
         self.i = self.item_class(name='John\xa3', age='22')
         self.output = BytesIO()
         self.ie = self._get_exporter()

tests/test_loader.py

@@ -1,4 +1,5 @@
 import unittest
+import dataclasses
 
 import attr
 from itemadapter import ItemAdapter
@@ -10,13 +11,6 @@ from scrapy.loader import ItemLoader
 from scrapy.selector import Selector
 
 
-try:
-    from dataclasses import make_dataclass, field as dataclass_field
-except ImportError:
-    make_dataclass = None
-    dataclass_field = None
-
-
 # test items
 class NameItem(Item):
     name = Field()
@@ -41,6 +35,11 @@ class AttrsNameItem:
     name = attr.ib(default="")
 
 
+@dataclasses.dataclass
+class TestDataClass:
+    name: list = dataclasses.field(default_factory=list)
+
+
 # test item loaders
 class NameItemLoader(ItemLoader):
     default_item_class = TestItem
@@ -187,16 +186,8 @@ class InitializationFromAttrsItemTest(InitializationTestMixin, unittest.TestCase
     item_class = AttrsNameItem
 
 
-@unittest.skipIf(not make_dataclass, "dataclasses module is not available")
 class InitializationFromDataClassTest(InitializationTestMixin, unittest.TestCase):
-
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        if make_dataclass:
-            self.item_class = make_dataclass(
-                "TestDataClass",
-                [("name", list, dataclass_field(default_factory=list))],
-            )
+    item_class = TestDataClass
 
 
 class BaseNoInputReprocessingLoader(ItemLoader):

tests/test_pipeline_files.py

@@ -7,6 +7,7 @@ from shutil import rmtree
 from tempfile import mkdtemp
 from unittest import mock, skipIf
 from urllib.parse import urlparse
+import dataclasses
 
 import attr
 from itemadapter import ItemAdapter
@@ -32,13 +33,6 @@ from scrapy.utils.test import (
 )
 
 
-try:
-    from dataclasses import make_dataclass, field as dataclass_field
-except ImportError:
-    make_dataclass = None
-    dataclass_field = None
-
-
 def _mocked_download_func(request, info):
     response = request.meta.get('response')
     return response() if callable(response) else response
@@ -226,24 +220,19 @@ class FilesPipelineTestCaseFieldsItem(FilesPipelineTestCaseFieldsMixin, unittest
     item_class = FilesPipelineTestItem
 
 
-@skipIf(not make_dataclass, "dataclasses module is not available")
-class FilesPipelineTestCaseFieldsDataClass(FilesPipelineTestCaseFieldsMixin, unittest.TestCase):
+@dataclasses.dataclass
+class FilesPipelineTestDataClass:
+    name: str
+    # default fields
+    file_urls: list = dataclasses.field(default_factory=list)
+    files: list = dataclasses.field(default_factory=list)
+    # overridden fields
+    custom_file_urls: list = dataclasses.field(default_factory=list)
+    custom_files: list = dataclasses.field(default_factory=list)
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        if make_dataclass:
-            self.item_class = make_dataclass(
-                "FilesPipelineTestDataClass",
-                [
-                    ("name", str),
-                    # default fields
-                    ("file_urls", list, dataclass_field(default_factory=list)),
-                    ("files", list, dataclass_field(default_factory=list)),
-                    # overridden fields
-                    ("custom_file_urls", list, dataclass_field(default_factory=list)),
-                    ("custom_files", list, dataclass_field(default_factory=list)),
-                ],
-            )
+
+class FilesPipelineTestCaseFieldsDataClass(FilesPipelineTestCaseFieldsMixin, unittest.TestCase):
+    item_class = FilesPipelineTestDataClass
 
 
 @attr.s

tests/test_pipeline_images.py

@@ -4,6 +4,7 @@ import random
 from shutil import rmtree
 from tempfile import mkdtemp
 from unittest import skipIf
+import dataclasses
 
 import attr
 from itemadapter import ItemAdapter
@@ -16,13 +17,6 @@ from scrapy.settings import Settings
 from scrapy.utils.python import to_bytes
 
 
-try:
-    from dataclasses import make_dataclass, field as dataclass_field
-except ImportError:
-    make_dataclass = None
-    dataclass_field = None
-
-
 try:
     from PIL import Image
 except ImportError:
@@ -203,25 +197,19 @@ class ImagesPipelineTestCaseFieldsItem(ImagesPipelineTestCaseFieldsMixin, unitte
     item_class = ImagesPipelineTestItem
 
 
-@skipIf(not make_dataclass, "dataclasses module is not available")
-class ImagesPipelineTestCaseFieldsDataClass(ImagesPipelineTestCaseFieldsMixin, unittest.TestCase):
-    item_class = None
+@dataclasses.dataclass
+class ImagesPipelineTestDataClass:
+    name: str
+    # default fields
+    image_urls: list = dataclasses.field(default_factory=list)
+    images: list = dataclasses.field(default_factory=list)
+    # overridden fields
+    custom_image_urls: list = dataclasses.field(default_factory=list)
+    custom_images: list = dataclasses.field(default_factory=list)
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        if make_dataclass:
-            self.item_class = make_dataclass(
-                "FilesPipelineTestDataClass",
-                [
-                    ("name", str),
-                    # default fields
-                    ("image_urls", list, dataclass_field(default_factory=list)),
-                    ("images", list, dataclass_field(default_factory=list)),
-                    # overridden fields
-                    ("custom_image_urls", list, dataclass_field(default_factory=list)),
-                    ("custom_images", list, dataclass_field(default_factory=list)),
-                ],
-            )
+
+class ImagesPipelineTestCaseFieldsDataClass(ImagesPipelineTestCaseFieldsMixin, unittest.TestCase):
+    item_class = ImagesPipelineTestDataClass
 
 
 @attr.s

tests/test_utils_serialize.py

@@ -1,6 +1,7 @@
 import datetime
 import json
 import unittest
+import dataclasses
 from decimal import Decimal
 
 import attr
@@ -10,12 +11,6 @@ from scrapy.http import Request, Response
 from scrapy.utils.serialize import ScrapyJSONEncoder
 
 
-try:
-    from dataclasses import make_dataclass
-except ImportError:
-    make_dataclass = None
-
-
 class JsonEncoderTestCase(unittest.TestCase):
 
     def setUp(self):
@@ -56,12 +51,13 @@ class JsonEncoderTestCase(unittest.TestCase):
         self.assertIn(r.url, rs)
         self.assertIn(str(r.status), rs)
 
-    @unittest.skipIf(not make_dataclass, "No dataclass support")
     def test_encode_dataclass_item(self):
-        TestDataClass = make_dataclass(
-            "TestDataClass",
-            [("name", str), ("url", str), ("price", int)],
-        )
+        @dataclasses.dataclass
+        class TestDataClass:
+            name: str
+            url: str
+            price: int
+
         item = TestDataClass(name="Product", url="http://product.org", price=1)
         encoded = self.encoder.encode(item)
         self.assertEqual(