feat(mlop-2454): add protection to host setting on cassandra_client

Makefile

@@ -76,7 +76,7 @@ style-check:
 	@echo "Code Style"
 	@echo "=========="
 	@echo ""
-	@python -m black --check -t py39 --exclude="build/|buck-out/|dist/|_build/|pip/|\.pip/|\.git/|\.hg/|\.mypy_cache/|\.tox/|\.venv/" . && echo "\n\nSuccess" || (echo "\n\nFailure\n\nYou need to run \"make apply-style\" to apply style formatting to your code"; exit 1)
+	@python -m black --check -t py39 --exclude="build/|buck-out/|dist/|_build/|pip/|\.pip/|\.git/|\.hg/|\.mypy_cache/|\.tox/|\.venv/|venv/" . && echo "\n\nSuccess" || (echo "\n\nFailure\n\nYou need to run \"make apply-style\" to apply style formatting to your code"; exit 1)
 
 .PHONY: quality-check
 ## run code quality checks with flake8
@@ -85,7 +85,7 @@ quality-check:
 	@echo "Flake 8"
 	@echo "======="
 	@echo ""
-	@python -m flake8 && echo "Success"
+	@python -m flake8 --exclude="venv"  && echo "Success"
 	@echo ""
 
 .PHONY: type-check
@@ -95,7 +95,7 @@ type-check:
 	@echo "mypy"
 	@echo "===="
 	@echo ""
-	@python -m mypy butterfree
+	@python -m mypy --exclude="venv" butterfree
 
 .PHONY: checks
 ## run all code checks
@@ -104,7 +104,7 @@ checks: style-check quality-check type-check
 .PHONY: apply-style
 ## fix stylistic errors with black
 apply-style:
-	@python -m black -t py39 --exclude="build/|buck-out/|dist/|_build/|pip/|\.pip/|\.git/|\.hg/|\.mypy_cache/|\.tox/|\.venv/" .
+	@python -m black -t py39 --exclude="build/|buck-out/|dist/|_build/|pip/|\.pip/|\.git/|\.hg/|\.mypy_cache/|\.tox/|\.venv/|venv/" .
 	@python -m isort --atomic butterfree/ tests/
 
 .PHONY: clean

butterfree/clients/cassandra_client.py

@@ -1,7 +1,7 @@
 """CassandraClient entity."""
 
 from ssl import CERT_REQUIRED, PROTOCOL_TLSv1
-from typing import Dict, List, Optional
+from typing import Dict, List, Optional, Union
 
 from cassandra.auth import PlainTextAuthProvider
 from cassandra.cluster import (
@@ -16,6 +16,12 @@
 from typing_extensions import TypedDict
 
 from butterfree.clients import AbstractClient
+from butterfree.configs.logger import __logger
+
+logger = __logger("cassandra_client")
+
+EMPTY_STRING_HOST_ERROR = "The value of Cassandra host is empty. Please fill correctly with your endpoints"  # noqa: E501
+GENERIC_INVALID_HOST_ERROR = "The Cassandra host must be a valid string, a string that represents a list or list of strings"  # noqa: E501
 
 
 class CassandraColumn(TypedDict):
@@ -53,12 +59,48 @@ def __init__(
         user: Optional[str] = None,
         password: Optional[str] = None,
     ) -> None:
-        self.host = host
+        self.host = self._validate_and_format_cassandra_host(host)
+        logger.info(f"The host setted is {self.host}")
         self.keyspace = keyspace
         self.user = user
         self.password = password
         self._session: Optional[Session] = None
 
+    def _validate_and_format_cassandra_host(self, host: Union[List, str]):
+        """
+        Validate and format the provided Cassandra host input.
+
+        This method checks if the input `host` is either a string, a list of strings, or
+        a list containing a single string with comma-separated values. It splits the string
+        by commas and trims whitespace, returning a list of hosts. If the input is already
+        a list of strings, it returns that list. If the input is empty or invalid, a
+        ValueError is raised.
+
+        Args:
+            host (str | list): The Cassandra host input, which can be a comma-separated
+                            string or a list of string endpoints.
+
+        Returns:
+            list: A list of formatted Cassandra host strings.
+
+        Raises:
+            ValueError: If the input is an empty string or if it is not a string
+                        (or a representation of a list) or a list of strings.
+        """  # noqa: E501
+        if isinstance(host, str):
+            if host:
+                return [item.strip() for item in host.split(",")]
+            else:
+                raise ValueError(EMPTY_STRING_HOST_ERROR)
+
+        if isinstance(host, list):
+            if len(host) == 1 and isinstance(host[0], str):
+                return [item.strip() for item in host[0].split(",")]
+            elif all(isinstance(item, str) for item in host):
+                return host
+
+        raise ValueError(GENERIC_INVALID_HOST_ERROR)
+
     @property
     def conn(self, *, ssl_path: str = None) -> Session:  # type: ignore
         """Establishes a Cassandra connection."""

tests/unit/butterfree/clients/test_cassandra_client.py

@@ -1,8 +1,14 @@
 from typing import Any, Dict, List
 from unittest.mock import MagicMock
 
+import pytest
+
 from butterfree.clients import CassandraClient
-from butterfree.clients.cassandra_client import CassandraColumn
+from butterfree.clients.cassandra_client import (
+    EMPTY_STRING_HOST_ERROR,
+    GENERIC_INVALID_HOST_ERROR,
+    CassandraColumn,
+)
 
 
 def sanitize_string(query: str) -> str:
@@ -86,3 +92,47 @@ def test_cassandra_create_table(
         query = cassandra_client.sql.call_args[0][0]
 
         assert sanitize_string(query) == sanitize_string(expected_query)
+
+    def test_initialize_with_string_host(self):
+        client = CassandraClient(host="127.0.0.0, 127.0.0.1", keyspace="dummy_keyspace")
+        assert client.host == ["127.0.0.0", "127.0.0.1"]
+
+    def test_initialize_with_list_host(self):
+        client = CassandraClient(
+            host=["127.0.0.0", "127.0.0.1"], keyspace="test_keyspace"
+        )
+        assert client.host == ["127.0.0.0", "127.0.0.1"]
+
+    def test_initialize_with_empty_string_host(self):
+        with pytest.raises(
+            ValueError,
+            match=EMPTY_STRING_HOST_ERROR,
+        ):
+            CassandraClient(host="", keyspace="test_keyspace")
+
+    def test_initialize_with_none_host(self):
+        with pytest.raises(
+            ValueError,
+            match=GENERIC_INVALID_HOST_ERROR,
+        ):
+            CassandraClient(host=None, keyspace="test_keyspace")
+
+    def test_initialize_with_invalid_host_type(self):
+        with pytest.raises(
+            ValueError,
+            match=GENERIC_INVALID_HOST_ERROR,
+        ):
+            CassandraClient(host=123, keyspace="test_keyspace")
+
+    def test_initialize_with_invalid_list_host(self):
+        with pytest.raises(
+            ValueError,
+            match=GENERIC_INVALID_HOST_ERROR,
+        ):
+            CassandraClient(host=["127.0.0.0", 123], keyspace="test_keyspace")
+
+    def test_initialize_with_list_of_string_hosts(self):
+        client = CassandraClient(
+            host=["127.0.0.0, 127.0.0.1"], keyspace="test_keyspace"
+        )
+        assert client.host == ["127.0.0.0", "127.0.0.1"]

tests/unit/butterfree/transform/transformations/conftest.py

@@ -62,7 +62,7 @@ def target_df_spark(spark_context, spark_session):
             "timestamp": "2016-04-11 11:31:11",
             "feature1": 200,
             "feature2": 200,
-            "feature__cos": 0.48718767500700594,
+            "feature__cos": 0.4871876750070059,
         },
         {
             "id": 1,