test: clean up test framework

Author: jmcnamara

xlsxwriter/test/comparison/output/.gitignore

@@ -0,0 +1,4 @@
+# Output dir for xlsx files created by the tests programs.
+# These are ignored since we only need them for testing.
+*.xlsx
+

xlsxwriter/test/excel_comparison_test.py

@@ -9,6 +9,7 @@
 
 import os
 import unittest
+from typing import Any, Dict, List
 
 from .helperfunctions import _compare_xlsx_files
 
@@ -20,29 +21,62 @@ class ExcelComparisonTest(unittest.TestCase):
 
     """
 
-    def set_filename(self, filename):
-        # Set the filename and paths for the test xlsx files.
-        self.maxDiff = None
-        self.got_filename = ""
-        self.exp_filename = ""
-        self.ignore_files = []
-        self.ignore_elements = {}
-        self.test_dir = "xlsxwriter/test/comparison/"
-        self.vba_dir = self.test_dir + "xlsx_files/"
-        self.image_dir = self.test_dir + "images/"
-        self.theme_dir = self.test_dir + "themes/"
+    def __init__(self, *args: Any) -> None:
+        """
+        Initialize the ExcelComparisonTest instance.
 
+        Args:
+            *args: Variable arguments passed to unittest.TestCase.
+        """
+        super().__init__(*args)
+
+        # pylint: disable=invalid-name
+        self.maxDiff: None = None
+
+        self.got_filename: str = ""
+        self.exp_filename: str = ""
+        self.ignore_files: List[str] = []
+        self.ignore_elements: Dict[str, Any] = {}
+        self.txt_filename: str = ""
+        self.delete_output: bool = True
+
+        # Set the paths for the test files.
+        self.test_dir: str = "xlsxwriter/test/comparison/"
+        self.vba_dir: str = self.test_dir + "xlsx_files/"
+        self.image_dir: str = self.test_dir + "images/"
+        self.theme_dir: str = self.test_dir + "themes/"
+        self.output_dir: str = self.test_dir + "output/"
+
+    def set_filename(self, filename: str) -> None:
+        """
+        Set the filenames for the Excel comparison test.
+
+        Args:
+            filename (str): The base filename for the test files.
+        """
         # The reference Excel generated file.
         self.exp_filename = self.test_dir + "xlsx_files/" + filename
 
         # The generated XlsxWriter file.
-        self.got_filename = self.test_dir + "_test_" + filename
+        self.got_filename = self.output_dir + "py_" + filename
+
+    def set_text_file(self, filename: str) -> None:
+        """
+        Set the filename and path for text files used in tests.
 
-    def set_text_file(self, filename):
+        Args:
+            filename (str): The name of the text file.
+        """
         # Set the filename and path for text files used in tests.
         self.txt_filename = self.test_dir + "xlsx_files/" + filename
 
-    def assertExcelEqual(self):
+    def assertExcelEqual(self) -> None:  # pylint: disable=invalid-name
+        """
+        Compare the generated file with the reference Excel file.
+
+        Raises:
+            AssertionError: If the files are not equivalent.
+        """
         # Compare the generate file and the reference Excel file.
         got, exp = _compare_xlsx_files(
             self.got_filename,
@@ -53,7 +87,12 @@ def assertExcelEqual(self):
 
         self.assertEqual(exp, got)
 
-    def tearDown(self):
+    def tearDown(self) -> None:
+        """
+        Clean up after each test by removing temporary files.
+        Raises:
+            OSError: If there is an error deleting the file.
+        """
         # Cleanup by removing the temp excel file created for testing.
-        if os.path.exists(self.got_filename):
+        if self.delete_output and os.path.exists(self.got_filename):
             os.remove(self.got_filename)