Package up base db and atomic db test suites into re-usable classes

eth/db/backends/base.py

@@ -40,7 +40,7 @@ def delete(self, key: bytes) -> None:
         try:
             del self[key]
         except KeyError:
-            return None
+            pass
 
     def __iter__(self) -> Iterator[bytes]:
         raise NotImplementedError("By default, DB classes cannot be iterated.")

eth/db/backends/level.py

@@ -62,6 +62,8 @@ def _exists(self, key: bytes) -> bool:
         return self.db.get(key) is not None
 
     def __delitem__(self, key: bytes) -> None:
+        if self.db.get(key) is None:
+            raise KeyError(key)
         self.db.delete(key)
 
     @contextmanager

eth/tools/db/atomic.py

@@ -0,0 +1,158 @@
+import pytest
+
+from eth_utils import ValidationError
+
+from eth.abc import AtomicDatabaseAPI
+
+
+class AtomicDatabaseBatchAPITestSuite:
+    def test_atomic_batch_set_and_get(self, atomic_db: AtomicDatabaseAPI) -> None:
+        with atomic_db.atomic_batch() as batch:
+            batch.set(b'1', b'2')
+            assert batch.get(b'1') == b'2'
+
+        assert atomic_db.get(b'1') == b'2'
+
+    def test_atomic_db_cannot_recursively_batch(self, atomic_db: AtomicDatabaseAPI) -> None:
+        with atomic_db.atomic_batch() as batch:
+            assert not hasattr(batch, 'atomic_batch')
+
+    def test_atomic_db_with_set_and_delete_batch(self, atomic_db: AtomicDatabaseAPI) -> None:
+        atomic_db[b'key-1'] = b'origin'
+
+        with atomic_db.atomic_batch() as batch:
+            batch.delete(b'key-1')
+
+            assert b'key-1' not in batch
+            with pytest.raises(KeyError):
+                assert batch[b'key-1']
+
+        with pytest.raises(KeyError):
+            atomic_db[b'key-1']
+
+    def test_atomic_db_unbatched_sets_are_immediate(self, atomic_db: AtomicDatabaseAPI) -> None:
+        atomic_db[b'1'] = b'A'
+
+        with atomic_db.atomic_batch() as batch:
+            # Unbatched changes are immediate, and show up in batch reads
+            atomic_db[b'1'] = b'B'
+            assert batch[b'1'] == b'B'
+
+            batch[b'1'] = b'C1'
+
+            # It doesn't matter what changes happen underlying, all reads now
+            # show the write applied to the batch db handle
+            atomic_db[b'1'] = b'C2'
+            assert batch[b'1'] == b'C1'
+
+        # the batch write should overwrite any intermediate changes
+        assert atomic_db[b'1'] == b'C1'
+
+    def test_atomic_db_unbatched_deletes_are_immediate(self, atomic_db: AtomicDatabaseAPI) -> None:
+        atomic_db[b'1'] = b'A'
+
+        with atomic_db.atomic_batch() as batch:
+            assert b'1' in batch
+
+            # Unbatched changes are immediate, and show up in batch reads
+            del atomic_db[b'1']
+
+            assert b'1' not in batch
+
+            batch[b'1'] = b'C1'
+
+            # It doesn't matter what changes happen underlying, all reads now
+            # show the write applied to the batch db handle
+            atomic_db[b'1'] = b'C2'
+            assert batch[b'1'] == b'C1'
+
+        # the batch write should overwrite any intermediate changes
+        assert atomic_db[b'1'] == b'C1'
+
+    def test_atomic_db_cannot_use_batch_after_context(self, atomic_db: AtomicDatabaseAPI) -> None:
+        atomic_db[b'1'] = b'A'
+
+        with atomic_db.atomic_batch() as batch:
+            batch[b'1'] = b'B'
+
+        # set
+        with pytest.raises(ValidationError):
+            batch[b'1'] = b'C'
+
+        with pytest.raises(ValidationError):
+            batch.set(b'1', b'C')
+
+        # get
+        with pytest.raises(ValidationError):
+            batch[b'1']
+
+        with pytest.raises(ValidationError):
+            batch.get(b'1')
+
+        # exists
+        with pytest.raises(ValidationError):
+            b'1' in batch
+
+        with pytest.raises(ValidationError):
+            batch.exists(b'1')
+
+        # delete
+        with pytest.raises(ValidationError):
+            del batch[b'1']
+
+        with pytest.raises(ValidationError):
+            batch.delete(b'1')
+
+        # none of the invalid changes above should change the original db
+        assert atomic_db[b'1'] == b'B'
+
+    def test_atomic_db_with_reverted_delete_batch(self, atomic_db: AtomicDatabaseAPI) -> None:
+        class CustomException(Exception):
+            pass
+
+        atomic_db[b'key-1'] = b'origin'
+
+        with pytest.raises(CustomException):
+            with atomic_db.atomic_batch() as batch:
+                batch.delete(b'key-1')
+
+                assert b'key-1' not in batch
+                with pytest.raises(KeyError):
+                    assert batch[b'key-1']
+
+                raise CustomException('pretend something went wrong')
+
+        assert atomic_db[b'key-1'] == b'origin'
+
+    def test_atomic_db_temporary_state_dropped_across_batches(self,
+                                                              atomic_db: AtomicDatabaseAPI) -> None:
+        class CustomException(Exception):
+            pass
+
+        atomic_db[b'key-1'] = b'origin'
+
+        with pytest.raises(CustomException):
+            with atomic_db.atomic_batch() as batch:
+                batch.delete(b'key-1')
+                batch.set(b'key-2', b'val-2')
+                raise CustomException('pretend something went wrong')
+
+        with atomic_db.atomic_batch() as batch:
+            assert batch[b'key-1'] == b'origin'
+            assert b'key-2' not in batch
+
+    def test_atomic_db_with_exception_batch(self, atomic_db: AtomicDatabaseAPI) -> None:
+        atomic_db.set(b'key-1', b'value-1')
+
+        try:
+            with atomic_db.atomic_batch() as batch:
+                batch.set(b'key-1', b'new-value-1')
+                batch.set(b'key-2', b'value-2')
+                raise Exception
+        except Exception:
+            pass
+
+        assert atomic_db.get(b'key-1') == b'value-1'
+
+        with pytest.raises(KeyError):
+            atomic_db[b'key-2']

eth/tools/db/base.py

@@ -0,0 +1,76 @@
+import pytest
+
+from eth.abc import DatabaseAPI
+
+
+class DatabaseAPITestSuite:
+    def test_database_api_get(self, db: DatabaseAPI) -> None:
+        db[b'key-1'] = b'value-1'
+        assert db.get(b'key-1') == b'value-1'
+
+    def test_database_api_item_getter(self, db: DatabaseAPI) -> None:
+        db[b'key-1'] = b'value-1'
+        assert db[b'key-1'] == b'value-1'
+
+    def test_database_api_get_missing_key(self, db: DatabaseAPI) -> None:
+        assert b'key-1' not in db
+        assert db.get(b'key-1') is None
+
+    def test_database_api_item_getter_missing_key(self, db: DatabaseAPI) -> None:
+        assert b'key-1' not in db
+        with pytest.raises(KeyError):
+            db[b'key-1']
+
+    def test_database_api_set(self, db: DatabaseAPI) -> None:
+        db[b'key-1'] = b'value-1'
+        assert db[b'key-1'] == b'value-1'
+        db[b'key-1'] = b'value-2'
+        assert db[b'key-1'] == b'value-2'
+
+    def test_database_api_item_setter(self, db: DatabaseAPI) -> None:
+        db.set(b'key-1', b'value-1')
+        assert db[b'key-1'] == b'value-1'
+        db.set(b'key-1', b'value-2')
+        assert db[b'key-1'] == b'value-2'
+
+    def test_database_api_exists(self, db: DatabaseAPI) -> None:
+        assert db.exists(b'key-1') is False
+
+        db[b'key-1'] = b'value-1'
+
+        assert db.exists(b'key-1') is True
+
+    def test_database_api_contains_checking(self, db: DatabaseAPI) -> None:
+        assert b'key-1' not in db
+
+        db[b'key-1'] = b'value-1'
+
+        assert b'key-1' in db
+
+    def test_database_api_delete(self, db: DatabaseAPI) -> None:
+        db[b'key-1'] = b'value-1'
+
+        assert b'key-1' in db
+
+        db.delete(b'key-1')
+
+        assert not db.exists(b'key-1')
+        assert b'key-1' not in db
+
+    def test_database_api_item_delete(self, db: DatabaseAPI) -> None:
+        db[b'key-1'] = b'value-1'
+
+        assert b'key-1' in db
+
+        del db[b'key-1']
+
+        assert b'key-1' not in db
+
+    def test_database_api_delete_missing_key(self, db: DatabaseAPI) -> None:
+        assert b'key-1' not in db
+        db.delete(b'key-1')
+
+    def test_database_api_item_delete_missing_key(self, db: DatabaseAPI) -> None:
+        assert b'key-1' not in db
+        with pytest.raises(KeyError):
+            del db[b'key-1']

newsfragments/1813.feature.rst

@@ -0,0 +1 @@
+Package up test suites for the ``DatabaseAPI`` and ``AtomicDatabaseAPI`` to be class-based to make them reusable by other libaries.

tests/database/test_atomic_database_api.py

@@ -0,0 +1,30 @@
+import pytest
+
+from eth.db.atomic import AtomicDB
+from eth.db.backends.level import LevelDB
+
+from eth.tools.db.base import DatabaseAPITestSuite
+from eth.tools.db.atomic import AtomicDatabaseBatchAPITestSuite
+
+
+@pytest.fixture(params=['atomic', 'level'])
+def atomic_db(request, tmpdir):
+    if request.param == 'atomic':
+        return AtomicDB()
+    elif request.param == 'level':
+        return LevelDB(db_path=tmpdir.mkdir("level_db_path"))
+    else:
+        raise ValueError("Unexpected database type: {}".format(request.param))
+
+
+@pytest.fixture
+def db(atomic_db):
+    return atomic_db
+
+
+class TestAtomicDatabaseBatchAPI(AtomicDatabaseBatchAPITestSuite):
+    pass
+
+
+class TestAtomicDatabaseAPI(DatabaseAPITestSuite):
+    pass