Exception classes are updated (message, source) (#3)

TestgresException
- new: RO-property message. It returns str(self)
- new: RO-property source. It returns None
- new: method __str__. It returns a value of message property

InvalidOperationException
- new: __init__(self, message: str, source: typing.Optional[str] = None)
- new: RO-property message
- new: RO-property source
- new: method __repr__

CI tests are added, too.

Author: dmitry-lipetsk

.gitignore

@@ -8,3 +8,4 @@ __pycache__/
 dist/
 env/
 venv/
+logs/

__init__.py

@@ -0,0 +1,6 @@
+[pytest]
+testpaths = tests
+log_file_level = NOTSET
+log_file_format = %(levelname)8s [%(asctime)s] %(message)s
+log_file_date_format=%Y-%m-%d %H:%M:%S
+

pytest.ini

@@ -8,12 +8,15 @@ rm -rf $VENV_PATH
 python -m venv "${VENV_PATH}"
 export VIRTUAL_ENV_DISABLE_PROMPT=1
 source "${VENV_PATH}/bin/activate"
+pip install -r tests/requirements.txt
 
 # install testgres' dependencies
 export PYTHONPATH=$(pwd)
-# $PIP install .
 
-pip install flake8 flake8-pyproject
-flake8
+# Check codestyle
+flake8 .
+
+# Run builtin tests
+python3 -m pytest -l -vvv tests
 
 set +eux

run_tests3.sh

@@ -1,9 +1,56 @@
 # coding: utf-8
+import typing
 
 
 class TestgresException(Exception):
-    pass
+    @property
+    def message(self) -> str:
+        assert isinstance(self, TestgresException)
+        r = super().__str__()
+        assert r is not None
+        assert type(r) == str  # noqa: E721
+        return r
+
+    @property
+    def source(self) -> typing.Optional[str]:
+        assert isinstance(self, TestgresException)
+        return None
+
+    def __str__(self) -> str:
+        r = self.message
+        assert type(r) == str  # noqa: E721
+        return r
 
 
 class InvalidOperationException(TestgresException):
-    pass
+    _message: str
+    _source: typing.Optional[str]
+
+    def __init__(self, message: str, source: typing.Optional[str] = None):
+        assert type(message) == str  # noqa: E721
+        assert source is None or type(source) == str  # noqa: E721
+        super().__init__()
+        self._message = message
+        self._source = source
+        return
+
+    @property
+    def message(self) -> str:
+        assert type(self._message) == str  # noqa: E721
+        return self._message
+
+    @property
+    def source(self) -> str:
+        assert self._source is None or type(self._source) == str  # noqa: E721
+        return self._source
+
+    def __repr__(self) -> str:
+        # It must be overrided!
+        assert type(self) == InvalidOperationException  # noqa: E721
+        r = "{}({}, {})".format(
+            __class__.__name__,
+            repr(self._message),
+            repr(self._source),
+        )
+        assert type(r) == str  # noqa: E721
+        return r