Merge pull request #4392 from tybug/db-equality

Implement `__eq__` for `ExampleDatabase` subclasses

Author: tybug

.github/workflows/main.yml

@@ -268,6 +268,7 @@ jobs:
           # pyodide can't run multiple processes internally, so parallelize explicitly over
           # discovered test files instead (20 at a time)
           TEST_FILES=$(python -m pytest -p no:cacheprovider --setup-plan hypothesis-python/tests/cover | grep ^hypothesis-python/ | cut -d " " -f 1)
+          echo "test files: $TEST_FILES"
           parallel --max-procs 100% --max-args 20 --keep-order --line-buffer \
             python -m pytest -p no:cacheprovider <<< $TEST_FILES
 

hypothesis-python/RELEASE.rst

@@ -0,0 +1,3 @@
+RELEASE_TYPE: patch
+
+All |ExampleDatabase| implementations in Hypothesis now implement ``__eq__``.

hypothesis-python/src/hypothesis/database.py

@@ -347,6 +347,9 @@ def __init__(self) -> None:
     def __repr__(self) -> str:
         return f"InMemoryExampleDatabase({self.data!r})"
 
+    def __eq__(self, other: object) -> bool:
+        return isinstance(other, InMemoryExampleDatabase) and self.data is other.data
+
     def fetch(self, key: bytes) -> Iterable[bytes]:
         yield from self.data.get(key, ())
 
@@ -414,6 +417,11 @@ def __init__(self, path: StrPathT) -> None:
     def __repr__(self) -> str:
         return f"DirectoryBasedExampleDatabase({self.path!r})"
 
+    def __eq__(self, other: object) -> bool:
+        return (
+            isinstance(other, DirectoryBasedExampleDatabase) and self.path == other.path
+        )
+
     def _key_path(self, key: bytes) -> Path:
         try:
             return self.keypaths[key]
@@ -630,6 +638,9 @@ def __init__(self, db: ExampleDatabase) -> None:
     def __repr__(self) -> str:
         return f"ReadOnlyDatabase({self._wrapped!r})"
 
+    def __eq__(self, other: object) -> bool:
+        return isinstance(other, ReadOnlyDatabase) and self._wrapped == other._wrapped
+
     def fetch(self, key: bytes) -> Iterable[bytes]:
         yield from self._wrapped.fetch(key)
 
@@ -681,6 +692,11 @@ def __init__(self, *dbs: ExampleDatabase) -> None:
     def __repr__(self) -> str:
         return "MultiplexedDatabase({})".format(", ".join(map(repr, self._wrapped)))
 
+    def __eq__(self, other: object) -> bool:
+        return (
+            isinstance(other, MultiplexedDatabase) and self._wrapped == other._wrapped
+        )
+
     def fetch(self, key: bytes) -> Iterable[bytes]:
         seen = set()
         for db in self._wrapped:
@@ -828,6 +844,15 @@ def __repr__(self) -> str:
             f"repo={self.repo!r}, artifact_name={self.artifact_name!r})"
         )
 
+    def __eq__(self, other: object) -> bool:
+        return (
+            isinstance(other, GitHubArtifactDatabase)
+            and self.owner == other.owner
+            and self.repo == other.repo
+            and self.artifact_name == other.artifact_name
+            and self.path == other.path
+        )
+
     def _prepare_for_io(self) -> None:
         assert self._artifact is not None, "Artifact not loaded."
 
@@ -1061,6 +1086,9 @@ def __init__(self, db: ExampleDatabase) -> None:
     def __repr__(self) -> str:
         return f"BackgroundWriteDatabase({self._db!r})"
 
+    def __eq__(self, other: object) -> bool:
+        return isinstance(other, BackgroundWriteDatabase) and self._db == other._db
+
     def _worker(self) -> None:
         while True:
             method, args = self._queue.get()

hypothesis-python/src/hypothesis/extra/redis.py

@@ -57,6 +57,14 @@ def __repr__(self) -> str:
             f"RedisExampleDatabase({self.redis!r}, expire_after={self._expire_after!r})"
         )
 
+    def __eq__(self, other: object) -> bool:
+        return (
+            isinstance(other, RedisExampleDatabase)
+            and self.redis == other.redis
+            and self._prefix == other._prefix
+            and self.listener_channel == other.listener_channel
+        )
+
     @contextmanager
     def _pipeline(
         self,

hypothesis-python/tests/conjecture/common.py

@@ -14,8 +14,6 @@
 from random import Random
 from typing import Optional
 
-import pytest
-
 from hypothesis import HealthCheck, Phase, assume, settings, strategies as st
 from hypothesis.control import current_build_context, currently_in_test_context
 from hypothesis.internal.conjecture import engine as engine_module
@@ -104,6 +102,9 @@ def accept(f):
 
 
 def fresh_data(*, random=None, observer=None) -> ConjectureData:
+    # support importing this file from our nose job, which doesn't have pytest
+    import pytest
+
     context = current_build_context() if currently_in_test_context() else None
     if context is not None and settings().backend == "crosshair":
         # we should reeaxmine fresh_data sometime and see if we can replace it

hypothesis-python/tests/cover/test_database_backend.py

@@ -802,3 +802,50 @@ def test_deprecated_example_database_memory():
 @checks_deprecated_behaviour
 def test_deprecated_example_database_no_args():
     ExampleDatabase()
+
+
+@pytest.mark.parametrize(
+    "db1, db2",
+    [
+        (DirectoryBasedExampleDatabase("a"), DirectoryBasedExampleDatabase("a")),
+        (
+            MultiplexedDatabase(
+                DirectoryBasedExampleDatabase("a"), DirectoryBasedExampleDatabase("b")
+            ),
+            MultiplexedDatabase(
+                DirectoryBasedExampleDatabase("a"), DirectoryBasedExampleDatabase("b")
+            ),
+        ),
+        (
+            ReadOnlyDatabase(DirectoryBasedExampleDatabase("a")),
+            ReadOnlyDatabase(DirectoryBasedExampleDatabase("a")),
+        ),
+        (
+            GitHubArtifactDatabase("owner1", "repo1"),
+            GitHubArtifactDatabase("owner1", "repo1"),
+        ),
+    ],
+)
+def test_database_equal(db1, db2):
+    assert db1 == db2
+
+
+@pytest.mark.parametrize(
+    "db1, db2",
+    [
+        (InMemoryExampleDatabase(), InMemoryExampleDatabase()),
+        (InMemoryExampleDatabase(), DirectoryBasedExampleDatabase("a")),
+        (BackgroundWriteDatabase(InMemoryExampleDatabase()), InMemoryExampleDatabase()),
+        (DirectoryBasedExampleDatabase("a"), DirectoryBasedExampleDatabase("b")),
+        (
+            ReadOnlyDatabase(DirectoryBasedExampleDatabase("a")),
+            ReadOnlyDatabase(DirectoryBasedExampleDatabase("b")),
+        ),
+        (
+            GitHubArtifactDatabase("owner1", "repo1"),
+            GitHubArtifactDatabase("owner2", "repo2"),
+        ),
+    ],
+)
+def test_database_not_equal(db1, db2):
+    assert db1 != db2

hypothesis-python/tests/cover/test_testdecorators.py

@@ -50,6 +50,7 @@
     skipif_emscripten,
     xfail_on_crosshair,
 )
+from tests.conjecture.common import buffer_size_limit
 
 # This particular test file is run under both pytest and nose, so it can't
 # rely on pytest-specific helpers like `pytest.raises` unless we define a
@@ -518,7 +519,7 @@ def f(v):
 
 
 def test_notes_high_overrun_rates_in_unsatisfiable_error():
-    @given(st.binary(min_size=9000))
+    @given(st.binary(min_size=100))
     @settings(
         suppress_health_check=[
             HealthCheck.data_too_large,
@@ -529,11 +530,14 @@ def test_notes_high_overrun_rates_in_unsatisfiable_error():
     def f(v):
         pass
 
-    with raises(
-        Unsatisfiable,
-        match=(
-            r"1000 of 1000 examples were too large to finish generating; "
-            r"try reducing the typical size of your inputs\?"
+    with (
+        raises(
+            Unsatisfiable,
+            match=(
+                r"1000 of 1000 examples were too large to finish generating; "
+                r"try reducing the typical size of your inputs\?"
+            ),
         ),
+        buffer_size_limit(10),
     ):
         f()

hypothesis-python/tests/redis/test_redis_exampledatabase.py

@@ -142,3 +142,10 @@ def listener(event):
     db.save(b"a", b"c")
     flush_messages(db)
     assert calls == 3
+
+
+def test_redis_equality():
+    redis = FakeRedis()
+    assert RedisExampleDatabase(redis) == RedisExampleDatabase(redis)
+    # FakeRedis() != FakeRedis(), not much we can do here
+    assert RedisExampleDatabase(FakeRedis()) != RedisExampleDatabase(FakeRedis())