We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
scrapy check command ignores contracts with the same URL
### Description
When testing callbacks with the same URL, only one callback is tested.

### Reproduce
```python
class DemoSpider(Spider):
    name = 'demo_spider'

    def returns_item_with_url(self, response):
        """ method which returns request
        @url http://scrapy.org
        @returns items 1 1
        """
        return TestItem(url=response.url)

    def returns_item_with_name(self, response):
        """ method which returns request
        @url http://scrapy.org
        @returns items 1 1
        """
        return TestItem(name='scrapy')
```

Then run `scrapy check`.

You'll get the following output:

```
.
----------------------------------------------------------------------
Ran 1 contract in 0.894s

OK
```

### Reason
This is default behavior for crawlers to filter same URLs.

### Solution
Use `dont_filter` in requests returned by `ContractsManager`.

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `scrapy/contracts/__init__.py`
Content:
```
1 import sys
2 import re
3 from functools import wraps
4 from inspect import getmembers
5 from unittest import TestCase
6 
7 from scrapy.http import Request
8 from scrapy.utils.spider import iterate_spider_output
9 from scrapy.utils.python import get_spec
10 
11 
12 class ContractsManager(object):
13     contracts = {}
14 
15     def __init__(self, contracts):
16         for contract in contracts:
17             self.contracts[contract.name] = contract
18 
19     def tested_methods_from_spidercls(self, spidercls):
20         methods = []
21         for key, value in getmembers(spidercls):
22             if (callable(value) and value.__doc__ and
23                     re.search(r'^\s*@', value.__doc__, re.MULTILINE)):
24                 methods.append(key)
25 
26         return methods
27 
28     def extract_contracts(self, method):
29         contracts = []
30         for line in method.__doc__.split('\n'):
31             line = line.strip()
32 
33             if line.startswith('@'):
34                 name, args = re.match(r'@(\w+)\s*(.*)', line).groups()
35                 args = re.split(r'\s+', args)
36 
37                 contracts.append(self.contracts[name](method, *args))
38 
39         return contracts
40 
41     def from_spider(self, spider, results):
42         requests = []
43         for method in self.tested_methods_from_spidercls(type(spider)):
44             bound_method = spider.__getattribute__(method)
45             requests.append(self.from_method(bound_method, results))
46 
47         return requests
48 
49     def from_method(self, method, results):
50         contracts = self.extract_contracts(method)
51         if contracts:
52             request_cls = Request
53             for contract in contracts:
54                 if contract.request_cls is not None:
55                     request_cls = contract.request_cls
56 
57             # calculate request args
58             args, kwargs = get_spec(request_cls.__init__)
59             kwargs['callback'] = method
60             for contract in contracts:
61                 kwargs = contract.adjust_request_args(kwargs)
62 
63             args.remove('self')
64 
65             # check if all positional arguments are defined in kwargs
66             if set(args).issubset(set(kwargs)):
67                 request = request_cls(**kwargs)
68 
69                 # execute pre and post hooks in order
70                 for contract in reversed(contracts):
71                     request = contract.add_pre_hook(request, results)
72                 for contract in contracts:
73                     request = contract.add_post_hook(request, results)
74 
75                 self._clean_req(request, method, results)
76                 return request
77 
78     def _clean_req(self, request, method, results):
79         """ stop the request from returning objects and records any errors """
80 
81         cb = request.callback
82 
83         @wraps(cb)
84         def cb_wrapper(response):
85             try:
86                 output = cb(response)
87                 output = list(iterate_spider_output(output))
88             except:
89                 case = _create_testcase(method, 'callback')
90                 results.addError(case, sys.exc_info())
91 
92         def eb_wrapper(failure):
93             case = _create_testcase(method, 'errback')
94             exc_info = failure.type, failure.value, failure.getTracebackObject()
95             results.addError(case, exc_info)
96 
97         request.callback = cb_wrapper
98         request.errback = eb_wrapper
99 
100 
101 class Contract(object):
102     """ Abstract class for contracts """
103     request_cls = None
104 
105     def __init__(self, method, *args):
106         self.testcase_pre = _create_testcase(method, '@%s pre-hook' % self.name)
107         self.testcase_post = _create_testcase(method, '@%s post-hook' % self.name)
108         self.args = args
109 
110     def add_pre_hook(self, request, results):
111         if hasattr(self, 'pre_process'):
112             cb = request.callback
113 
114             @wraps(cb)
115             def wrapper(response):
116                 try:
117                     results.startTest(self.testcase_pre)
118                     self.pre_process(response)
119                     results.stopTest(self.testcase_pre)
120                 except AssertionError:
121                     results.addFailure(self.testcase_pre, sys.exc_info())
122                 except Exception:
123                     results.addError(self.testcase_pre, sys.exc_info())
124                 else:
125                     results.addSuccess(self.testcase_pre)
126                 finally:
127                     return list(iterate_spider_output(cb(response)))
128 
129             request.callback = wrapper
130 
131         return request
132 
133     def add_post_hook(self, request, results):
134         if hasattr(self, 'post_process'):
135             cb = request.callback
136 
137             @wraps(cb)
138             def wrapper(response):
139                 output = list(iterate_spider_output(cb(response)))
140                 try:
141                     results.startTest(self.testcase_post)
142                     self.post_process(output)
143                     results.stopTest(self.testcase_post)
144                 except AssertionError:
145                     results.addFailure(self.testcase_post, sys.exc_info())
146                 except Exception:
147                     results.addError(self.testcase_post, sys.exc_info())
148                 else:
149                     results.addSuccess(self.testcase_post)
150                 finally:
151                     return output
152 
153             request.callback = wrapper
154 
155         return request
156 
157     def adjust_request_args(self, args):
158         return args
159 
160 
161 def _create_testcase(method, desc):
162     spider = method.__self__.name
163 
164     class ContractTestCase(TestCase):
165         def __str__(_self):
166             return "[%s] %s (%s)" % (spider, method.__name__, desc)
167 
168     name = '%s_%s' % (spider, method.__name__)
169     setattr(ContractTestCase, name, lambda x: x)
170     return ContractTestCase(name)
171
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/scrapy/contracts/__init__.py b/scrapy/contracts/__init__.py
--- a/scrapy/contracts/__init__.py
+++ b/scrapy/contracts/__init__.py
@@ -56,7 +56,12 @@
 
             # calculate request args
             args, kwargs = get_spec(request_cls.__init__)
+
+            # Don't filter requests to allow
+            # testing different callbacks on the same URL.
+            kwargs['dont_filter'] = True
             kwargs['callback'] = method
+
             for contract in contracts:
                 kwargs = contract.adjust_request_args(kwargs)

{"golden_diff": "diff --git a/scrapy/contracts/__init__.py b/scrapy/contracts/__init__.py\n--- a/scrapy/contracts/__init__.py\n+++ b/scrapy/contracts/__init__.py\n@@ -56,7 +56,12 @@\n \n             # calculate request args\n             args, kwargs = get_spec(request_cls.__init__)\n+\n+            # Don't filter requests to allow\n+            # testing different callbacks on the same URL.\n+            kwargs['dont_filter'] = True\n             kwargs['callback'] = method\n+\n             for contract in contracts:\n                 kwargs = contract.adjust_request_args(kwargs)\n", "issue": "scrapy check command ignores contracts with the same URL\n### Description\r\nWhen testing callbacks with the same URL, only one callback is tested.\r\n\r\n### Reproduce\r\n```python\r\nclass DemoSpider(Spider):\r\n    name = 'demo_spider'\r\n\r\n    def returns_item_with_url(self, response):\r\n        \"\"\" method which returns request\r\n        @url http://scrapy.org\r\n        @returns items 1 1\r\n        \"\"\"\r\n        return TestItem(url=response.url)\r\n\r\n    def returns_item_with_name(self, response):\r\n        \"\"\" method which returns request\r\n        @url http://scrapy.org\r\n        @returns items 1 1\r\n        \"\"\"\r\n        return TestItem(name='scrapy')\r\n```\r\n\r\nThen run `scrapy check`.\r\n\r\nYou'll get the following output:\r\n\r\n```\r\n.\r\n----------------------------------------------------------------------\r\nRan 1 contract in 0.894s\r\n\r\nOK\r\n```\r\n\r\n### Reason\r\nThis is default behavior for crawlers to filter same URLs.\r\n\r\n### Solution\r\nUse `dont_filter` in requests returned by `ContractsManager`.\n", "before_files": [{"content": "import sys\nimport re\nfrom functools import wraps\nfrom inspect import getmembers\nfrom unittest import TestCase\n\nfrom scrapy.http import Request\nfrom scrapy.utils.spider import iterate_spider_output\nfrom scrapy.utils.python import get_spec\n\n\nclass ContractsManager(object):\n    contracts = {}\n\n    def __init__(self, contracts):\n        for contract in contracts:\n            self.contracts[contract.name] = contract\n\n    def tested_methods_from_spidercls(self, spidercls):\n        methods = []\n        for key, value in getmembers(spidercls):\n            if (callable(value) and value.__doc__ and\n                    re.search(r'^\\s*@', value.__doc__, re.MULTILINE)):\n                methods.append(key)\n\n        return methods\n\n    def extract_contracts(self, method):\n        contracts = []\n        for line in method.__doc__.split('\\n'):\n            line = line.strip()\n\n            if line.startswith('@'):\n                name, args = re.match(r'@(\\w+)\\s*(.*)', line).groups()\n                args = re.split(r'\\s+', args)\n\n                contracts.append(self.contracts[name](method, *args))\n\n        return contracts\n\n    def from_spider(self, spider, results):\n        requests = []\n        for method in self.tested_methods_from_spidercls(type(spider)):\n            bound_method = spider.__getattribute__(method)\n            requests.append(self.from_method(bound_method, results))\n\n        return requests\n\n    def from_method(self, method, results):\n        contracts = self.extract_contracts(method)\n        if contracts:\n            request_cls = Request\n            for contract in contracts:\n                if contract.request_cls is not None:\n                    request_cls = contract.request_cls\n\n            # calculate request args\n            args, kwargs = get_spec(request_cls.__init__)\n            kwargs['callback'] = method\n            for contract in contracts:\n                kwargs = contract.adjust_request_args(kwargs)\n\n            args.remove('self')\n\n            # check if all positional arguments are defined in kwargs\n            if set(args).issubset(set(kwargs)):\n                request = request_cls(**kwargs)\n\n                # execute pre and post hooks in order\n                for contract in reversed(contracts):\n                    request = contract.add_pre_hook(request, results)\n                for contract in contracts:\n                    request = contract.add_post_hook(request, results)\n\n                self._clean_req(request, method, results)\n                return request\n\n    def _clean_req(self, request, method, results):\n        \"\"\" stop the request from returning objects and records any errors \"\"\"\n\n        cb = request.callback\n\n        @wraps(cb)\n        def cb_wrapper(response):\n            try:\n                output = cb(response)\n                output = list(iterate_spider_output(output))\n            except:\n                case = _create_testcase(method, 'callback')\n                results.addError(case, sys.exc_info())\n\n        def eb_wrapper(failure):\n            case = _create_testcase(method, 'errback')\n            exc_info = failure.type, failure.value, failure.getTracebackObject()\n            results.addError(case, exc_info)\n\n        request.callback = cb_wrapper\n        request.errback = eb_wrapper\n\n\nclass Contract(object):\n    \"\"\" Abstract class for contracts \"\"\"\n    request_cls = None\n\n    def __init__(self, method, *args):\n        self.testcase_pre = _create_testcase(method, '@%s pre-hook' % self.name)\n        self.testcase_post = _create_testcase(method, '@%s post-hook' % self.name)\n        self.args = args\n\n    def add_pre_hook(self, request, results):\n        if hasattr(self, 'pre_process'):\n            cb = request.callback\n\n            @wraps(cb)\n            def wrapper(response):\n                try:\n                    results.startTest(self.testcase_pre)\n                    self.pre_process(response)\n                    results.stopTest(self.testcase_pre)\n                except AssertionError:\n                    results.addFailure(self.testcase_pre, sys.exc_info())\n                except Exception:\n                    results.addError(self.testcase_pre, sys.exc_info())\n                else:\n                    results.addSuccess(self.testcase_pre)\n                finally:\n                    return list(iterate_spider_output(cb(response)))\n\n            request.callback = wrapper\n\n        return request\n\n    def add_post_hook(self, request, results):\n        if hasattr(self, 'post_process'):\n            cb = request.callback\n\n            @wraps(cb)\n            def wrapper(response):\n                output = list(iterate_spider_output(cb(response)))\n                try:\n                    results.startTest(self.testcase_post)\n                    self.post_process(output)\n                    results.stopTest(self.testcase_post)\n                except AssertionError:\n                    results.addFailure(self.testcase_post, sys.exc_info())\n                except Exception:\n                    results.addError(self.testcase_post, sys.exc_info())\n                else:\n                    results.addSuccess(self.testcase_post)\n                finally:\n                    return output\n\n            request.callback = wrapper\n\n        return request\n\n    def adjust_request_args(self, args):\n        return args\n\n\ndef _create_testcase(method, desc):\n    spider = method.__self__.name\n\n    class ContractTestCase(TestCase):\n        def __str__(_self):\n            return \"[%s] %s (%s)\" % (spider, method.__name__, desc)\n\n    name = '%s_%s' % (spider, method.__name__)\n    setattr(ContractTestCase, name, lambda x: x)\n    return ContractTestCase(name)\n", "path": "scrapy/contracts/__init__.py"}], "after_files": [{"content": "import sys\nimport re\nfrom functools import wraps\nfrom inspect import getmembers\nfrom unittest import TestCase\n\nfrom scrapy.http import Request\nfrom scrapy.utils.spider import iterate_spider_output\nfrom scrapy.utils.python import get_spec\n\n\nclass ContractsManager(object):\n    contracts = {}\n\n    def __init__(self, contracts):\n        for contract in contracts:\n            self.contracts[contract.name] = contract\n\n    def tested_methods_from_spidercls(self, spidercls):\n        methods = []\n        for key, value in getmembers(spidercls):\n            if (callable(value) and value.__doc__ and\n                    re.search(r'^\\s*@', value.__doc__, re.MULTILINE)):\n                methods.append(key)\n\n        return methods\n\n    def extract_contracts(self, method):\n        contracts = []\n        for line in method.__doc__.split('\\n'):\n            line = line.strip()\n\n            if line.startswith('@'):\n                name, args = re.match(r'@(\\w+)\\s*(.*)', line).groups()\n                args = re.split(r'\\s+', args)\n\n                contracts.append(self.contracts[name](method, *args))\n\n        return contracts\n\n    def from_spider(self, spider, results):\n        requests = []\n        for method in self.tested_methods_from_spidercls(type(spider)):\n            bound_method = spider.__getattribute__(method)\n            requests.append(self.from_method(bound_method, results))\n\n        return requests\n\n    def from_method(self, method, results):\n        contracts = self.extract_contracts(method)\n        if contracts:\n            request_cls = Request\n            for contract in contracts:\n                if contract.request_cls is not None:\n                    request_cls = contract.request_cls\n\n            # calculate request args\n            args, kwargs = get_spec(request_cls.__init__)\n\n            # Don't filter requests to allow\n            # testing different callbacks on the same URL.\n            kwargs['dont_filter'] = True\n            kwargs['callback'] = method\n\n            for contract in contracts:\n                kwargs = contract.adjust_request_args(kwargs)\n\n            args.remove('self')\n\n            # check if all positional arguments are defined in kwargs\n            if set(args).issubset(set(kwargs)):\n                request = request_cls(**kwargs)\n\n                # execute pre and post hooks in order\n                for contract in reversed(contracts):\n                    request = contract.add_pre_hook(request, results)\n                for contract in contracts:\n                    request = contract.add_post_hook(request, results)\n\n                self._clean_req(request, method, results)\n                return request\n\n    def _clean_req(self, request, method, results):\n        \"\"\" stop the request from returning objects and records any errors \"\"\"\n\n        cb = request.callback\n\n        @wraps(cb)\n        def cb_wrapper(response):\n            try:\n                output = cb(response)\n                output = list(iterate_spider_output(output))\n            except:\n                case = _create_testcase(method, 'callback')\n                results.addError(case, sys.exc_info())\n\n        def eb_wrapper(failure):\n            case = _create_testcase(method, 'errback')\n            exc_info = failure.type, failure.value, failure.getTracebackObject()\n            results.addError(case, exc_info)\n\n        request.callback = cb_wrapper\n        request.errback = eb_wrapper\n\n\nclass Contract(object):\n    \"\"\" Abstract class for contracts \"\"\"\n    request_cls = None\n\n    def __init__(self, method, *args):\n        self.testcase_pre = _create_testcase(method, '@%s pre-hook' % self.name)\n        self.testcase_post = _create_testcase(method, '@%s post-hook' % self.name)\n        self.args = args\n\n    def add_pre_hook(self, request, results):\n        if hasattr(self, 'pre_process'):\n            cb = request.callback\n\n            @wraps(cb)\n            def wrapper(response):\n                try:\n                    results.startTest(self.testcase_pre)\n                    self.pre_process(response)\n                    results.stopTest(self.testcase_pre)\n                except AssertionError:\n                    results.addFailure(self.testcase_pre, sys.exc_info())\n                except Exception:\n                    results.addError(self.testcase_pre, sys.exc_info())\n                else:\n                    results.addSuccess(self.testcase_pre)\n                finally:\n                    return list(iterate_spider_output(cb(response)))\n\n            request.callback = wrapper\n\n        return request\n\n    def add_post_hook(self, request, results):\n        if hasattr(self, 'post_process'):\n            cb = request.callback\n\n            @wraps(cb)\n            def wrapper(response):\n                output = list(iterate_spider_output(cb(response)))\n                try:\n                    results.startTest(self.testcase_post)\n                    self.post_process(output)\n                    results.stopTest(self.testcase_post)\n                except AssertionError:\n                    results.addFailure(self.testcase_post, sys.exc_info())\n                except Exception:\n                    results.addError(self.testcase_post, sys.exc_info())\n                else:\n                    results.addSuccess(self.testcase_post)\n                finally:\n                    return output\n\n            request.callback = wrapper\n\n        return request\n\n    def adjust_request_args(self, args):\n        return args\n\n\ndef _create_testcase(method, desc):\n    spider = method.__self__.name\n\n    class ContractTestCase(TestCase):\n        def __str__(_self):\n            return \"[%s] %s (%s)\" % (spider, method.__name__, desc)\n\n    name = '%s_%s' % (spider, method.__name__)\n    setattr(ContractTestCase, name, lambda x: x)\n    return ContractTestCase(name)\n", "path": "scrapy/contracts/__init__.py"}]}