LCORE-293: config file utils

src/utils/checks.py

@@ -0,0 +1,27 @@
+"""Checks that are performed to configuration options."""
+
+import os
+from typing import Optional
+
+from pydantic import FilePath
+
+
+class InvalidConfigurationError(Exception):
+    """Lightspeed configuration is invalid."""
+
+
+def get_attribute_from_file(data: dict, file_name_key: str) -> Optional[str]:
+    """Retrieve value of an attribute from a file."""
+    file_path = data.get(file_name_key)
+    if file_path is not None:
+        with open(file_path, encoding="utf-8") as f:
+            return f.read().rstrip()
+    return None
+
+
+def file_check(path: FilePath, desc: str) -> None:
+    """Check that path is a readable regular file."""
+    if not os.path.isfile(path):
+        raise InvalidConfigurationError(f"{desc} '{path}' is not a file")
+    if not os.access(path, os.R_OK):
+        raise InvalidConfigurationError(f"{desc} '{path}' is not readable")

tests/unit/utils/test_checks.py

@@ -0,0 +1,77 @@
+import os
+import pytest
+
+from unittest.mock import patch
+
+from utils import checks
+
+
+@pytest.fixture
+def input_file(tmp_path):
+    """Create file manually using the tmp_path fixture."""
+    filename = os.path.join(tmp_path, "mydoc.csv")
+    with open(filename, "wt") as fout:
+        fout.write("some content!")
+    return filename
+
+
+def test_get_attribute_from_file_no_record():
+    """Test the get_attribute_from_file function when record is not in dictionary."""
+    # no data
+    d = {}
+
+    # non-existing key
+    key = ""
+    value = checks.get_attribute_from_file(d, key)
+    assert value is None
+
+    # non-existing key
+    key = "this-does-not-exists"
+    value = checks.get_attribute_from_file(d, "this-does-not-exists")
+    assert value is None
+
+
+def test_get_attribute_from_file_proper_record(input_file):
+    """Test the get_attribute_from_file function when record is present in dictionary."""
+    # existing key
+    key = "my_file"
+
+    # attribute with proper and existing filename
+    d = {key: input_file}
+
+    # file content should be read properly
+    value = checks.get_attribute_from_file(d, key)
+    assert value is not None
+    assert value == "some content!"
+
+
+def test_get_attribute_from_file_improper_filename():
+    """Test the get_attribute_from_file when the file does not exist."""
+    # existing key
+    key = "my_file"
+
+    # filename for file that does not exist
+    input_file = "this-does-not-exists"
+    d = {key: input_file}
+
+    with pytest.raises(FileNotFoundError, match="this-does-not-exists"):
+        checks.get_attribute_from_file(d, "my_file")
+
+
+def test_file_check_existing_file(input_file):
+    """Test the function file_check for existing file."""
+    # just call the function, it should not raise an exception
+    checks.file_check(input_file, "description")
+
+
+def test_file_check_non_existing_file():
+    """Test the function file_check for non existing file."""
+    with pytest.raises(checks.InvalidConfigurationError):
+        checks.file_check("does-not-exists", "description")
+
+
+def test_file_check_not_readable_file(input_file):
+    """Test the function file_check for not readable file."""
+    with patch("os.access", return_value=False):
+        with pytest.raises(checks.InvalidConfigurationError):
+            checks.file_check(input_file, "description")