PYTHON-4708 - Convert test.qcheck to async (#1832)

Author: NoahStapp

test/asynchronous/qcheck.py

@@ -0,0 +1,255 @@
+# Copyright 2009-present MongoDB, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import annotations
+
+import datetime
+import random
+import re
+import sys
+import traceback
+
+sys.path[0:0] = [""]
+
+from bson.dbref import DBRef
+from bson.objectid import ObjectId
+from bson.son import SON
+
+_IS_SYNC = False
+
+gen_target = 100
+reduction_attempts = 10
+examples = 5
+
+
+def lift(value):
+    return lambda: value
+
+
+def choose_lifted(generator_list):
+    return lambda: random.choice(generator_list)
+
+
+def my_map(generator, function):
+    return lambda: function(generator())
+
+
+def choose(list):
+    return lambda: random.choice(list)()
+
+
+def gen_range(start, stop):
+    return lambda: random.randint(start, stop)
+
+
+def gen_int():
+    max_int = 2147483647
+    return lambda: random.randint(-max_int - 1, max_int)
+
+
+def gen_float():
+    return lambda: (random.random() - 0.5) * sys.maxsize
+
+
+def gen_boolean():
+    return lambda: random.choice([True, False])
+
+
+def gen_printable_char():
+    return lambda: chr(random.randint(32, 126))
+
+
+def gen_printable_string(gen_length):
+    return lambda: "".join(gen_list(gen_printable_char(), gen_length)())
+
+
+def gen_char(set=None):
+    return lambda: bytes([random.randint(0, 255)])
+
+
+def gen_string(gen_length):
+    return lambda: b"".join(gen_list(gen_char(), gen_length)())
+
+
+def gen_unichar():
+    return lambda: chr(random.randint(1, 0xFFF))
+
+
+def gen_unicode(gen_length):
+    return lambda: "".join([x for x in gen_list(gen_unichar(), gen_length)() if x not in ".$"])
+
+
+def gen_list(generator, gen_length):
+    return lambda: [generator() for _ in range(gen_length())]
+
+
+def gen_datetime():
+    return lambda: datetime.datetime(
+        random.randint(1970, 2037),
+        random.randint(1, 12),
+        random.randint(1, 28),
+        random.randint(0, 23),
+        random.randint(0, 59),
+        random.randint(0, 59),
+        random.randint(0, 999) * 1000,
+    )
+
+
+def gen_dict(gen_key, gen_value, gen_length):
+    def a_dict(gen_key, gen_value, length):
+        result = {}
+        for _ in range(length):
+            result[gen_key()] = gen_value()
+        return result
+
+    return lambda: a_dict(gen_key, gen_value, gen_length())
+
+
+def gen_regexp(gen_length):
+    # TODO our patterns only consist of one letter.
+    # this is because of a bug in CPython's regex equality testing,
+    # which I haven't quite tracked down, so I'm just ignoring it...
+    def pattern():
+        return "".join(gen_list(choose_lifted("a"), gen_length)())
+
+    def gen_flags():
+        flags = 0
+        if random.random() > 0.5:
+            flags = flags | re.IGNORECASE
+        if random.random() > 0.5:
+            flags = flags | re.MULTILINE
+        if random.random() > 0.5:
+            flags = flags | re.VERBOSE
+
+        return flags
+
+    return lambda: re.compile(pattern(), gen_flags())
+
+
+def gen_objectid():
+    return lambda: ObjectId()
+
+
+def gen_dbref():
+    collection = gen_unicode(gen_range(0, 20))
+    return lambda: DBRef(collection(), gen_mongo_value(1, True)())
+
+
+def gen_mongo_value(depth, ref):
+    choices = [
+        gen_unicode(gen_range(0, 50)),
+        gen_printable_string(gen_range(0, 50)),
+        my_map(gen_string(gen_range(0, 1000)), bytes),
+        gen_int(),
+        gen_float(),
+        gen_boolean(),
+        gen_datetime(),
+        gen_objectid(),
+        lift(None),
+    ]
+    if ref:
+        choices.append(gen_dbref())
+    if depth > 0:
+        choices.append(gen_mongo_list(depth, ref))
+        choices.append(gen_mongo_dict(depth, ref))
+    return choose(choices)
+
+
+def gen_mongo_list(depth, ref):
+    return gen_list(gen_mongo_value(depth - 1, ref), gen_range(0, 10))
+
+
+def gen_mongo_dict(depth, ref=True):
+    return my_map(
+        gen_dict(gen_unicode(gen_range(0, 20)), gen_mongo_value(depth - 1, ref), gen_range(0, 10)),
+        SON,
+    )
+
+
+def simplify(case):  # TODO this is a hack
+    if isinstance(case, SON) and "$ref" not in case:
+        simplified = SON(case)  # make a copy!
+        if random.choice([True, False]):
+            # delete
+            simplified_keys = list(simplified)
+            if not len(simplified_keys):
+                return (False, case)
+            simplified.pop(random.choice(simplified_keys))
+            return (True, simplified)
+        else:
+            # simplify a value
+            simplified_items = list(simplified.items())
+            if not len(simplified_items):
+                return (False, case)
+            (key, value) = random.choice(simplified_items)
+            (success, value) = simplify(value)
+            simplified[key] = value
+            return (success, success and simplified or case)
+    if isinstance(case, list):
+        simplified = list(case)
+        if random.choice([True, False]):
+            # delete
+            if not len(simplified):
+                return (False, case)
+            simplified.pop(random.randrange(len(simplified)))
+            return (True, simplified)
+        else:
+            # simplify an item
+            if not len(simplified):
+                return (False, case)
+            index = random.randrange(len(simplified))
+            (success, value) = simplify(simplified[index])
+            simplified[index] = value
+            return (success, success and simplified or case)
+    return (False, case)
+
+
+async def reduce(case, predicate, reductions=0):
+    for _ in range(reduction_attempts):
+        (reduced, simplified) = simplify(case)
+        if reduced and not await predicate(simplified):
+            return await reduce(simplified, predicate, reductions + 1)
+    return (reductions, case)
+
+
+async def isnt(predicate):
+    async def is_not(x):
+        return not await predicate(x)
+
+    return is_not
+
+
+async def check(predicate, generator):
+    counter_examples = []
+    for _ in range(gen_target):
+        case = generator()
+        try:
+            if not await predicate(case):
+                reduction = await reduce(case, predicate)
+                counter_examples.append("after {} reductions: {!r}".format(*reduction))
+        except:
+            counter_examples.append(f"{case!r} : {traceback.format_exc()}")
+    return counter_examples
+
+
+async def check_unittest(test, predicate, generator):
+    counter_examples = await check(predicate, generator)
+    if counter_examples:
+        failures = len(counter_examples)
+        message = "\n".join(["    -> %s" % f for f in counter_examples[:examples]])
+        message = "found %d counter examples, displaying first %d:\n%s" % (
+            failures,
+            min(failures, examples),
+            message,
+        )
+        test.fail(message)

test/asynchronous/test_grid_file.py

@@ -21,17 +21,21 @@
 import sys
 import zipfile
 from io import BytesIO
-from test.asynchronous import AsyncIntegrationTest, AsyncUnitTest, async_client_context
+from test.asynchronous import (
+    AsyncIntegrationTest,
+    AsyncUnitTest,
+    async_client_context,
+    qcheck,
+    unittest,
+)
 
 from pymongo.asynchronous.database import AsyncDatabase
 
 sys.path[0:0] = [""]
 
-from test import IntegrationTest, qcheck, unittest
-from test.utils import EventListener, async_rs_or_single_client, rs_or_single_client
+from test.utils import EventListener, async_rs_or_single_client
 
 from bson.objectid import ObjectId
-from gridfs import GridFS
 from gridfs.asynchronous.grid_file import (
     _SEEK_CUR,
     _SEEK_END,
@@ -44,7 +48,7 @@
 from gridfs.errors import NoFile
 from pymongo import AsyncMongoClient
 from pymongo.asynchronous.helpers import aiter, anext
-from pymongo.errors import ConfigurationError, InvalidOperation, ServerSelectionTimeoutError
+from pymongo.errors import ConfigurationError, ServerSelectionTimeoutError
 from pymongo.message import _CursorAddress
 
 _IS_SYNC = False
@@ -407,8 +411,6 @@ async def test_multi_chunk_file(self):
         g = AsyncGridOut(self.db.fs, f._id)
         self.assertEqual(random_string, await g.read())
 
-    # TODO: https://jira.mongodb.org/browse/PYTHON-4708
-    @async_client_context.require_sync
     async def test_small_chunks(self):
         self.files = 0
         self.chunks = 0
@@ -431,7 +433,7 @@ async def helper(data):
             self.assertEqual(data, await g.read(10) + await g.read(10))
             return True
 
-        qcheck.check_unittest(self, helper, qcheck.gen_string(qcheck.gen_range(0, 20)))
+        await qcheck.check_unittest(self, helper, qcheck.gen_string(qcheck.gen_range(0, 20)))
 
     async def test_seek(self):
         f = AsyncGridIn(self.db.fs, chunkSize=3)

test/qcheck.py

@@ -25,6 +25,8 @@
 from bson.objectid import ObjectId
 from bson.son import SON
 
+_IS_SYNC = True
+
 gen_target = 100
 reduction_attempts = 10
 examples = 5
@@ -221,7 +223,10 @@ def reduce(case, predicate, reductions=0):
 
 
 def isnt(predicate):
-    return lambda x: not predicate(x)
+    def is_not(x):
+        return not predicate(x)
+
+    return is_not
 
 
 def check(predicate, generator):

test/test_grid_file.py

@@ -21,17 +21,21 @@
 import sys
 import zipfile
 from io import BytesIO
-from test import IntegrationTest, UnitTest, client_context
+from test import (
+    IntegrationTest,
+    UnitTest,
+    client_context,
+    qcheck,
+    unittest,
+)
 
 from pymongo.synchronous.database import Database
 
 sys.path[0:0] = [""]
 
-from test import IntegrationTest, qcheck, unittest
 from test.utils import EventListener, rs_or_single_client
 
 from bson.objectid import ObjectId
-from gridfs import GridFS
 from gridfs.errors import NoFile
 from gridfs.synchronous.grid_file import (
     _SEEK_CUR,
@@ -43,7 +47,7 @@
     GridOutCursor,
 )
 from pymongo import MongoClient
-from pymongo.errors import ConfigurationError, InvalidOperation, ServerSelectionTimeoutError
+from pymongo.errors import ConfigurationError, ServerSelectionTimeoutError
 from pymongo.message import _CursorAddress
 from pymongo.synchronous.helpers import iter, next
 
@@ -405,8 +409,6 @@ def test_multi_chunk_file(self):
         g = GridOut(self.db.fs, f._id)
         self.assertEqual(random_string, g.read())
 
-    # TODO: https://jira.mongodb.org/browse/PYTHON-4708
-    @client_context.require_sync
     def test_small_chunks(self):
         self.files = 0
         self.chunks = 0

tools/synchro.py

@@ -159,6 +159,7 @@
     "conftest.py",
     "pymongo_mocks.py",
     "utils_spec_runner.py",
+    "qcheck.py",
     "test_bulk.py",
     "test_client.py",
     "test_client_bulk_write.py",