added tests for all formatters; stylecheck workflow now also checks in tests now

tests/formatters/tests_attr_formatter.py

@@ -0,0 +1,23 @@
+import unittest
+from bs4 import BeautifulSoup
+from html_to_django.formatters.attr_formatter import format
+
+
+class TestAttrFormatter(unittest.TestCase):
+    def test_format(self) -> None:
+        soup = BeautifulSoup('<div dj-attr="class;my_class"></div>', "html.parser")
+        format(soup)
+        expected_result = '<div class="{{ my_class }}"></div>'
+        self.assertEqual(expected_result, str(soup))
+
+    def test_format_multiple(self) -> None:
+        soup = BeautifulSoup('<div dj-attr="class;my_class~id;my_id"></div>', "html.parser")
+        format(soup)
+        expected_result = '<div class="{{ my_class }}" id="{{ my_id }}"></div>'
+        self.assertEqual(expected_result, str(soup))
+
+    def test_format_overwrite_existing(self) -> None:
+        soup = BeautifulSoup('<div class="original_class" dj-attr="class;new_class"></div>', "html.parser")
+        format(soup)
+        expected_result = '<div class="{{ new_class }}"></div>'
+        self.assertEqual(expected_result, str(soup))