Introducing unit tests for DbMemory

Change-Id: I103db30b019df814d48accc60c1ebe378e353d78
Signed-off-by: Eduardo Sousa <eduardosousa@av.it.pt>

diff --git a/osm_common/tests/test_dbmemory.py b/osm_common/tests/test_dbmemory.py
new file mode 100644 (file)
index 0000000..0b62485
--- /dev/null
+++ b/osm_common/tests/test_dbmemory.py
@@ -0,0 +1,600 @@
+import http
+import logging
+import pytest
+
+from unittest.mock import MagicMock
+from osm_common.dbbase import DbException
+from osm_common.dbmemory import DbMemory
+
+__author__ = 'Eduardo Sousa <eduardosousa@av.it.pt>'
+
+@pytest.fixture
+def db_memory():
+    db = DbMemory()
+    return db
+
+@pytest.fixture
+def db_memory_with_data():
+    db = DbMemory()
+
+    db.create("test", {"_id": 1, "data": 1})
+    db.create("test", {"_id": 2, "data": 2})
+    db.create("test", {"_id": 3, "data": 3})
+
+    return db
+
+
+
+def empty_exception_message():
+    return 'database exception '
+
+def get_one_exception_message(filter):
+    return "database exception Not found entry with filter='{}'".format(filter)
+
+def get_one_multiple_exception_message(filter):
+    return "database exception Found more than one entry with filter='{}'".format(filter)
+
+def del_one_exception_message(filter):
+    return "database exception Not found entry with filter='{}'".format(filter)
+
+def replace_exception_message(filter):
+    return "database exception Not found entry with filter='{}'".format(filter)
+
+def test_constructor():
+    db = DbMemory()
+
+    assert db.logger == logging.getLogger('db')
+    assert len(db.db) == 0
+
+def test_constructor_with_logger():
+    logger_name = 'db_local'
+
+    db = DbMemory(logger_name=logger_name)
+
+    assert db.logger == logging.getLogger(logger_name)
+    assert len(db.db) == 0
+
+def test_db_connect():
+    logger_name = 'db_local'
+    config = {'logger_name': logger_name}
+
+    db = DbMemory()
+    db.db_connect(config)
+
+    assert db.logger == logging.getLogger(logger_name)
+    assert len(db.db) == 0
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {}),
+    ("test", {"_id": 1}),
+    ("test", {"data": 1}),
+    ("test", {"_id": 1, "data": 1}),
+])
+def test_get_list_with_empty_db(db_memory, table, filter):
+    result = db_memory.get_list(table, filter)
+
+    assert len(result) == 0
+
+@pytest.mark.parametrize("table, filter, expected_data", [
+    ("test", {}, [{"_id": 1, "data": 1}, {"_id": 2, "data": 2}, {"_id": 3, "data": 3}]),
+    ("test", {"_id": 1}, [{"_id": 1, "data": 1}]),
+    ("test", {"data": 1}, [{"_id": 1, "data": 1}]),
+    ("test", {"_id": 1, "data": 1}, [{"_id": 1, "data": 1}]),
+    ("test", {"_id": 2}, [{"_id": 2, "data": 2}]),
+    ("test", {"data": 2}, [{"_id": 2, "data": 2}]),
+    ("test", {"_id": 2, "data": 2}, [{"_id": 2, "data": 2}]),
+    ("test", {"_id": 4}, []),
+    ("test", {"data": 4}, []),
+    ("test", {"_id": 4, "data": 4}, []),
+    ("test_table", {}, []),
+    ("test_table", {"_id": 1}, []),
+    ("test_table", {"data": 1}, []),
+    ("test_table", {"_id": 1, "data": 1}, []),
+])
+def test_get_list_with_non_empty_db(db_memory_with_data, table, filter, expected_data):
+    result = db_memory_with_data.get_list(table, filter)
+
+    assert len(result) == len(expected_data)
+    for data in expected_data:
+        assert data in result
+
+def test_get_list_exception(db_memory_with_data):
+    table = 'test'
+    filter = {}
+
+    db_memory_with_data._find = MagicMock(side_effect=Exception())
+
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.get_list(table, filter)
+    assert str(excinfo.value) == empty_exception_message()
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter, expected_data", [
+    ("test", {"_id": 1}, {"_id": 1, "data": 1}),
+    ("test", {"_id": 2}, {"_id": 2, "data": 2}),
+    ("test", {"_id": 3}, {"_id": 3, "data": 3}),
+    ("test", {"data": 1}, {"_id": 1, "data": 1}),
+    ("test", {"data": 2}, {"_id": 2, "data": 2}),
+    ("test", {"data": 3}, {"_id": 3, "data": 3}),
+    ("test", {"_id": 1, "data": 1}, {"_id": 1, "data": 1}),
+    ("test", {"_id": 2, "data": 2}, {"_id": 2, "data": 2}),
+    ("test", {"_id": 3, "data": 3}, {"_id": 3, "data": 3}),
+])
+def test_get_one(db_memory_with_data, table, filter, expected_data):
+    result = db_memory_with_data.get_one(table, filter)
+
+    assert result == expected_data
+    assert len(db_memory_with_data.db) == 1
+    assert table in db_memory_with_data.db
+    assert len(db_memory_with_data.db[table]) == 3
+    assert result in db_memory_with_data.db[table]
+
+@pytest.mark.parametrize("table, filter, expected_data", [
+    ("test", {}, {"_id": 1, "data": 1}),
+])
+def test_get_one_with_multiple_results(db_memory_with_data, table, filter, expected_data):
+    result = db_memory_with_data.get_one(table, filter, fail_on_more=False)
+
+    assert result == expected_data
+    assert len(db_memory_with_data.db) == 1
+    assert table in db_memory_with_data.db
+    assert len(db_memory_with_data.db[table]) == 3
+    assert result in db_memory_with_data.db[table]
+
+def test_get_one_with_multiple_results_exception(db_memory_with_data):
+    table = "test"
+    filter = {}
+
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.get_one(table, filter)
+
+    assert str(excinfo.value) == (empty_exception_message() + get_one_multiple_exception_message(filter))
+#    assert excinfo.value.http_code == http.HTTPStatus.CONFLICT
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {"_id": 4}),
+    ("test", {"data": 4}),
+    ("test", {"_id": 4, "data": 4}),
+    ("test_table", {"_id": 4}),
+    ("test_table", {"data": 4}),
+    ("test_table", {"_id": 4, "data": 4}),
+])
+def test_get_one_with_non_empty_db_exception(db_memory_with_data, table, filter):
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.get_one(table, filter)
+    assert str(excinfo.value) == (empty_exception_message() + get_one_exception_message(filter))
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {"_id": 4}),
+    ("test", {"data": 4}),
+    ("test", {"_id": 4, "data": 4}),
+    ("test_table", {"_id": 4}),
+    ("test_table", {"data": 4}),
+    ("test_table", {"_id": 4, "data": 4}),
+])
+def test_get_one_with_non_empty_db_none(db_memory_with_data, table, filter):
+    result = db_memory_with_data.get_one(table, filter, fail_on_empty=False)
+    
+    assert result == None
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {"_id": 4}),
+    ("test", {"data": 4}),
+    ("test", {"_id": 4, "data": 4}),
+    ("test_table", {"_id": 4}),
+    ("test_table", {"data": 4}),
+    ("test_table", {"_id": 4, "data": 4}),
+])
+def test_get_one_with_empty_db_exception(db_memory, table, filter):
+    with pytest.raises(DbException) as excinfo:
+        db_memory.get_one(table, filter)
+    assert str(excinfo.value) == (empty_exception_message() + get_one_exception_message(filter))
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {"_id": 4}),
+    ("test", {"data": 4}),
+    ("test", {"_id": 4, "data": 4}),
+    ("test_table", {"_id": 4}),
+    ("test_table", {"data": 4}),
+    ("test_table", {"_id": 4, "data": 4}),
+])
+def test_get_one_with_empty_db_none(db_memory, table, filter):
+    result = db_memory.get_one(table, filter, fail_on_empty=False)
+    
+    assert result == None
+
+def test_get_one_generic_exception(db_memory_with_data):
+    table = 'test'
+    filter = {}
+
+    db_memory_with_data._find = MagicMock(side_effect=Exception())
+
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.get_one(table, filter)
+    assert str(excinfo.value) == empty_exception_message()
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter, expected_data", [
+#    ("test", {}, []),
+    ("test", {"_id": 1}, [{"_id": 2, "data": 2}, {"_id": 3, "data": 3}]), 
+    ("test", {"_id": 2}, [{"_id": 1, "data": 1}, {"_id": 3, "data": 3}]), 
+    ("test", {"_id": 1, "data": 1}, [{"_id": 2, "data": 2}, {"_id": 3, "data": 3}]),
+    ("test", {"_id": 2, "data": 2}, [{"_id": 1, "data": 1}, {"_id": 3, "data": 3}]),
+])
+def test_del_list_with_non_empty_db(db_memory_with_data, table, filter, expected_data):
+    result = db_memory_with_data.del_list(table, filter)
+
+    assert result["deleted"] == (3 - len(expected_data))
+    assert len(db_memory_with_data.db) == 1
+    assert table in db_memory_with_data.db
+    assert len(db_memory_with_data.db[table]) == len(expected_data)
+    for data in expected_data:
+        assert data in db_memory_with_data.db[table]
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {}),
+    ("test", {"_id": 1}),
+    ("test", {"_id": 2}),
+    ("test", {"data": 1}),
+    ("test", {"data": 2}),
+    ("test", {"_id": 1, "data": 1}),
+    ("test", {"_id": 2, "data": 2}),
+])
+def test_del_list_with_empty_db(db_memory, table, filter):
+    result = db_memory.del_list(table, filter)
+    assert result['deleted'] == 0
+
+def test_del_list_generic_exception(db_memory_with_data):
+    table = 'test'
+    filter = {}
+
+    db_memory_with_data._find = MagicMock(side_effect=Exception())
+
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.del_list(table, filter)
+    assert str(excinfo.value) == empty_exception_message()
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter, data", [
+    ("test", {}, {"_id": 1, "data": 1}),
+    ("test", {"_id": 1}, {"_id": 1, "data": 1}),
+    ("test", {"data": 1}, {"_id": 1, "data": 1}),
+    ("test", {"_id": 1, "data": 1}, {"_id": 1, "data": 1}),
+    ("test", {"_id": 2}, {"_id": 2, "data": 2}),
+    ("test", {"data": 2}, {"_id": 2, "data": 2}),
+    ("test", {"_id": 2, "data": 2}, {"_id": 2, "data": 2}),
+])
+def test_del_one(db_memory_with_data, table, filter, data):
+    result = db_memory_with_data.del_one(table, filter)
+
+    assert result == {"deleted": 1}
+    assert len(db_memory_with_data.db) == 1
+    assert table in db_memory_with_data.db
+    assert len(db_memory_with_data.db[table]) == 2
+    assert data not in db_memory_with_data.db[table]
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {}),
+    ("test", {"_id": 1}),
+    ("test", {"_id": 2}),
+    ("test", {"data": 1}),
+    ("test", {"data": 2}),
+    ("test", {"_id": 1, "data": 1}),
+    ("test", {"_id": 2, "data": 2}),
+    ("test_table", {}),
+    ("test_table", {"_id": 1}),
+    ("test_table", {"_id": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test_table", {"_id": 1, "data": 1}),
+    ("test_table", {"_id": 2, "data": 2}),
+])
+def test_del_one_with_empty_db_exception(db_memory, table, filter):
+    with pytest.raises(DbException) as excinfo:
+        db_memory.del_one(table, filter)
+    assert str(excinfo.value) == (empty_exception_message() + del_one_exception_message(filter))
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {}),
+    ("test", {"_id": 1}),
+    ("test", {"_id": 2}),
+    ("test", {"data": 1}),
+    ("test", {"data": 2}),
+    ("test", {"_id": 1, "data": 1}),
+    ("test", {"_id": 2, "data": 2}),
+    ("test_table", {}),
+    ("test_table", {"_id": 1}),
+    ("test_table", {"_id": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test_table", {"_id": 1, "data": 1}),
+    ("test_table", {"_id": 2, "data": 2}),
+])
+def test_del_one_with_empty_db_none(db_memory, table, filter):
+    result = db_memory.del_one(table, filter, fail_on_empty=False)
+
+    assert result == None
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {"_id": 4}),
+    ("test", {"_id": 5}),
+    ("test", {"data": 4}),
+    ("test", {"data": 5}),
+    ("test", {"_id": 1, "data": 2}),
+    ("test", {"_id": 2, "data": 3}),
+    ("test_table", {}),
+    ("test_table", {"_id": 1}),
+    ("test_table", {"_id": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test_table", {"_id": 1, "data": 1}),
+    ("test_table", {"_id": 2, "data": 2}),
+])
+def test_del_one_with_non_empty_db_exception(db_memory_with_data, table, filter):
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.del_one(table, filter)
+    assert str(excinfo.value) == (empty_exception_message() + del_one_exception_message(filter))
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter", [
+    ("test", {"_id": 4}),
+    ("test", {"_id": 5}),
+    ("test", {"data": 4}),
+    ("test", {"data": 5}),
+    ("test", {"_id": 1, "data": 2}),
+    ("test", {"_id": 2, "data": 3}),
+    ("test_table", {}),
+    ("test_table", {"_id": 1}),
+    ("test_table", {"_id": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test_table", {"_id": 1, "data": 1}),
+    ("test_table", {"_id": 2, "data": 2}),
+])
+def test_del_one_with_non_empty_db_none(db_memory_with_data, table, filter):
+    result = db_memory_with_data.del_one(table, filter, fail_on_empty=False)
+
+    assert result == None
+
+@pytest.mark.parametrize("fail_on_empty", [
+    (True),
+    (False),
+])
+def test_del_one_generic_exception(db_memory_with_data, fail_on_empty):
+    table = 'test'
+    filter = {}
+
+    db_memory_with_data._find = MagicMock(side_effect=Exception())
+
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.del_one(table, filter, fail_on_empty=fail_on_empty)
+    assert str(excinfo.value) == empty_exception_message()
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter, indata", [
+    ("test", {}, {"_id": 1, "data": 42}),
+    ("test", {}, {"_id": 3, "data": 42}),
+    ("test", {"_id": 1}, {"_id": 3, "data": 42}),
+    ("test", {"_id": 3}, {"_id": 3, "data": 42}),
+    ("test", {"data": 1}, {"_id": 3, "data": 42}),
+    ("test", {"data": 3}, {"_id": 3, "data": 42}),
+    ("test", {"_id": 1, "data": 1}, {"_id": 3, "data": 42}),
+    ("test", {"_id": 3, "data": 3}, {"_id": 3, "data": 42}),
+])
+def test_replace(db_memory_with_data, table, filter, indata):
+    result = db_memory_with_data.replace(table, filter, indata)
+
+    assert result == {"updated": 1}
+    assert len(db_memory_with_data.db) == 1
+    assert table in db_memory_with_data.db
+    assert len(db_memory_with_data.db[table]) == 3
+    assert indata in db_memory_with_data.db[table]
+
+@pytest.mark.parametrize("table, filter, indata", [
+    ("test", {}, {'_id': 1, 'data': 1}),
+    ("test", {}, {'_id': 2, 'data': 1}),
+    ("test", {}, {'_id': 1, 'data': 2}),
+    ("test", {'_id': 1}, {'_id': 1, 'data': 1}),
+    ("test", {'_id': 1, 'data': 1}, {'_id': 1, 'data': 1}),
+    ("test_table", {}, {'_id': 1, 'data': 1}),
+    ("test_table", {}, {'_id': 2, 'data': 1}),
+    ("test_table", {}, {'_id': 1, 'data': 2}),
+    ("test_table", {'_id': 1}, {'_id': 1, 'data': 1}),
+    ("test_table", {'_id': 1, 'data': 1}, {'_id': 1, 'data': 1}),
+])
+def test_replace_without_data_exception(db_memory, table, filter, indata):
+    with pytest.raises(DbException) as excinfo:
+        db_memory.replace(table, filter, indata, fail_on_empty=True)
+    assert str(excinfo.value) == (empty_exception_message() + replace_exception_message(filter))
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter, indata", [
+    ("test", {}, {'_id': 1, 'data': 1}),
+    ("test", {}, {'_id': 2, 'data': 1}),
+    ("test", {}, {'_id': 1, 'data': 2}),
+    ("test", {'_id': 1}, {'_id': 1, 'data': 1}),
+    ("test", {'_id': 1, 'data': 1}, {'_id': 1, 'data': 1}),
+    ("test_table", {}, {'_id': 1, 'data': 1}),
+    ("test_table", {}, {'_id': 2, 'data': 1}),
+    ("test_table", {}, {'_id': 1, 'data': 2}),
+    ("test_table", {'_id': 1}, {'_id': 1, 'data': 1}),
+    ("test_table", {'_id': 1, 'data': 1}, {'_id': 1, 'data': 1}),
+])
+def test_replace_without_data_none(db_memory, table, filter, indata):
+    result = db_memory.replace(table, filter, indata, fail_on_empty=False)
+    assert result == None
+
+@pytest.mark.parametrize("table, filter, indata", [
+    ("test_table", {}, {'_id': 1, 'data': 1}),
+    ("test_table", {}, {'_id': 2, 'data': 1}),
+    ("test_table", {}, {'_id': 1, 'data': 2}),
+    ("test_table", {'_id': 1}, {'_id': 1, 'data': 1}),
+    ("test_table", {'_id': 1, 'data': 1}, {'_id': 1, 'data': 1}),
+])
+def test_replace_with_data_exception(db_memory_with_data, table, filter, indata):
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.replace(table, filter, indata, fail_on_empty=True)
+    assert str(excinfo.value) == (empty_exception_message() + replace_exception_message(filter))
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, filter, indata", [
+    ("test_table", {}, {'_id': 1, 'data': 1}),
+    ("test_table", {}, {'_id': 2, 'data': 1}),
+    ("test_table", {}, {'_id': 1, 'data': 2}),
+    ("test_table", {'_id': 1}, {'_id': 1, 'data': 1}),
+    ("test_table", {'_id': 1, 'data': 1}, {'_id': 1, 'data': 1}),
+])
+def test_replace_with_data_none(db_memory_with_data, table, filter, indata):
+    result = db_memory_with_data.replace(table, filter, indata, fail_on_empty=False)
+    assert result == None
+
+@pytest.mark.parametrize("fail_on_empty", [
+    (True),
+    (False),
+])
+def test_replace_generic_exception(db_memory_with_data, fail_on_empty):
+    table = 'test'
+    filter = {}
+    indata = {'_id': 1, 'data': 1}
+
+    db_memory_with_data._find = MagicMock(side_effect=Exception())
+
+    with pytest.raises(DbException) as excinfo:
+        db_memory_with_data.replace(table, filter, indata, fail_on_empty=fail_on_empty)
+    assert str(excinfo.value) == empty_exception_message()
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND
+
+@pytest.mark.parametrize("table, id, data", [
+    ("test", "1", {"data": 1}),
+    ("test", "1", {"data": 2}),
+    ("test", "2", {"data": 1}),
+    ("test", "2", {"data": 2}),
+    ("test_table", "1", {"data": 1}),
+    ("test_table", "1", {"data": 2}),
+    ("test_table", "2", {"data": 1}),
+    ("test_table", "2", {"data": 2}),
+    ("test", "1", {"data_1": 1, "data_2": 2}),
+    ("test", "1", {"data_1": 2, "data_2": 1}),
+    ("test", "2", {"data_1": 1, "data_2": 2}),
+    ("test", "2", {"data_1": 2, "data_2": 1}),
+    ("test_table", "1", {"data_1": 1, "data_2": 2}),
+    ("test_table", "1", {"data_1": 2, "data_2": 1}),
+    ("test_table", "2", {"data_1": 1, "data_2": 2}),
+    ("test_table", "2", {"data_1": 2, "data_2": 1}),
+])
+def test_create_with_empty_db_with_id(db_memory, table, id, data):
+    data_to_insert = data
+    data_to_insert['_id'] = id
+
+    returned_id = db_memory.create(table, data_to_insert)
+
+    assert returned_id == id
+    assert len(db_memory.db) == 1
+    assert table in db_memory.db
+    assert len(db_memory.db[table]) == 1
+    assert data_to_insert in db_memory.db[table]
+
+@pytest.mark.parametrize("table, id, data", [
+    ("test", "4", {"data": 1}),
+    ("test", "5", {"data": 2}),
+    ("test", "4", {"data": 1}),
+    ("test", "5", {"data": 2}),
+    ("test_table", "4", {"data": 1}),
+    ("test_table", "5", {"data": 2}),
+    ("test_table", "4", {"data": 1}),
+    ("test_table", "5", {"data": 2}),
+    ("test", "4", {"data_1": 1, "data_2": 2}),
+    ("test", "5", {"data_1": 2, "data_2": 1}),
+    ("test", "4", {"data_1": 1, "data_2": 2}),
+    ("test", "5", {"data_1": 2, "data_2": 1}),
+    ("test_table", "4", {"data_1": 1, "data_2": 2}),
+    ("test_table", "5", {"data_1": 2, "data_2": 1}),
+    ("test_table", "4", {"data_1": 1, "data_2": 2}),
+    ("test_table", "5", {"data_1": 2, "data_2": 1}),
+])
+def test_create_with_non_empty_db_with_id(db_memory_with_data, table, id, data):
+    data_to_insert = data
+    data_to_insert['_id'] = id
+
+    returned_id = db_memory_with_data.create(table, data_to_insert)
+
+    assert returned_id == id
+    assert len(db_memory_with_data.db) == (1 if table == 'test' else 2)
+    assert table in db_memory_with_data.db
+    assert len(db_memory_with_data.db[table]) == (4 if table == 'test' else 1)
+    assert data_to_insert in db_memory_with_data.db[table]
+
+@pytest.mark.parametrize("table, data", [
+    ("test", {"data": 1}),
+    ("test", {"data": 2}),
+    ("test", {"data": 1}),
+    ("test", {"data": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test", {"data_1": 1, "data_2": 2}),
+    ("test", {"data_1": 2, "data_2": 1}),
+    ("test", {"data_1": 1, "data_2": 2}),
+    ("test", {"data_1": 2, "data_2": 1}),
+    ("test_table", {"data_1": 1, "data_2": 2}),
+    ("test_table", {"data_1": 2, "data_2": 1}),
+    ("test_table", {"data_1": 1, "data_2": 2}),
+    ("test_table", {"data_1": 2, "data_2": 1}),
+])
+def test_create_with_empty_db_without_id(db_memory, table, data):
+    returned_id = db_memory.create(table, data)
+
+    assert len(db_memory.db) == 1
+    assert table in db_memory.db
+    assert len(db_memory.db[table]) == 1
+
+    data_inserted = data
+    data_inserted['_id'] = returned_id
+
+    assert data_inserted in db_memory.db[table]
+
+@pytest.mark.parametrize("table, data", [
+    ("test", {"data": 1}),
+    ("test", {"data": 2}),
+    ("test", {"data": 1}),
+    ("test", {"data": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test_table", {"data": 1}),
+    ("test_table", {"data": 2}),
+    ("test", {"data_1": 1, "data_2": 2}),
+    ("test", {"data_1": 2, "data_2": 1}),
+    ("test", {"data_1": 1, "data_2": 2}),
+    ("test", {"data_1": 2, "data_2": 1}),
+    ("test_table", {"data_1": 1, "data_2": 2}),
+    ("test_table", {"data_1": 2, "data_2": 1}),
+    ("test_table", {"data_1": 1, "data_2": 2}),
+    ("test_table", {"data_1": 2, "data_2": 1}),
+])
+def test_create_with_non_empty_db_without_id(db_memory_with_data, table, data):
+    returned_id = db_memory_with_data.create(table, data)
+
+    assert len(db_memory_with_data.db) == (1 if table == 'test' else 2)
+    assert table in db_memory_with_data.db
+    assert len(db_memory_with_data.db[table]) == (4 if table == 'test' else 1)
+    
+    data_inserted = data
+    data_inserted['_id'] = returned_id
+
+    assert data_inserted in db_memory_with_data.db[table]
+
+def test_create_with_exception(db_memory):
+    table = "test"
+    data = {"_id": 1, "data": 1}
+
+    db_memory.db = MagicMock()
+    db_memory.db.__contains__.side_effect = Exception()
+
+    with pytest.raises(DbException) as excinfo:
+        db_memory.create(table, data)
+    assert str(excinfo.value) == empty_exception_message()
+    assert excinfo.value.http_code == http.HTTPStatus.NOT_FOUND