diff --git a/tests/test_parser.py b/tests/test_parser.py
index a88b31d..0bdf8d0 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -12,18 +12,21 @@ from regex_humanizer.parser import (
     Group,
     Alternation,
     Anchor,
-    SpecialSequence,
 )
 
 
 class TestTokenizer:
+    """Tests for the tokenize function."""
+
     def test_tokenize_literal(self):
+        """Test tokenizing a literal string."""
         tokens = tokenize("abc")
         assert len(tokens) == 1
         assert tokens[0].type == "LITERAL"
         assert tokens[0].value == "abc"
 
     def test_tokenize_anchors(self):
+        """Test tokenizing anchor characters."""
         tokens = tokenize("^test$")
         assert len(tokens) == 3
         assert tokens[0].type == "ANCHOR_START"
@@ -31,18 +34,21 @@ class TestTokenizer:
         assert tokens[2].type == "ANCHOR_END"
 
     def test_tokenize_quantifiers(self):
+        """Test tokenizing quantifiers."""
         tokens = tokenize("a*")
         assert len(tokens) == 2
         assert tokens[0].type == "LITERAL"
         assert tokens[1].type == "STAR"
 
     def test_tokenize_character_class(self):
+        """Test tokenizing character classes."""
         tokens = tokenize("[abc]")
         assert len(tokens) >= 2
         assert tokens[0].type == "OPEN_BRACKET"
         assert tokens[-1].type == "CLOSE_BRACKET"
 
     def test_tokenize_groups(self):
+        """Test tokenizing groups."""
         tokens = tokenize("(abc)")
         assert len(tokens) == 3
         assert tokens[0].type == "OPEN_GROUP"
@@ -50,84 +56,117 @@ class TestTokenizer:
         assert tokens[2].type == "CLOSE_GROUP"
 
     def test_tokenize_alternation(self):
+        """Test tokenizing alternation."""
         tokens = tokenize("a|b")
         assert len(tokens) == 3
         assert tokens[0].type == "LITERAL"
         assert tokens[1].type == "ALTERNATION"
         assert tokens[2].type == "LITERAL"
 
+    def test_tokenize_escape(self):
+        """Test tokenizing escaped characters."""
+        tokens = tokenize(r"\.")
+        assert len(tokens) == 1
+        assert tokens[0].type == "ESCAPED"
+
+    def test_tokenize_special_sequences(self):
+        """Test tokenizing special sequences."""
+        tokens = tokenize(r"\d+\w*\s?")
+        assert len(tokens) >= 4
+
 
 class TestParser:
+    """Tests for the parse_regex function."""
+
     def test_parse_literal(self):
+        """Test parsing a literal pattern."""
         ast = parse_regex("hello")
         assert len(ast) == 1
         assert isinstance(ast[0], Literal)
         assert ast[0].value == "hello"
 
     def test_parse_character_class(self):
+        """Test parsing a character class."""
         ast = parse_regex("[abc]")
         assert len(ast) == 1
         assert isinstance(ast[0], CharacterClass)
 
     def test_parse_inverted_class(self):
+        """Test parsing an inverted character class."""
         ast = parse_regex("[^abc]")
         assert len(ast) == 1
         assert isinstance(ast[0], CharacterClass)
         assert ast[0].inverted is True
 
     def test_parse_quantifier_star(self):
+        """Test parsing the * quantifier."""
         ast = parse_regex("a*")
         assert len(ast) == 1
         assert isinstance(ast[0], Quantifier)
 
     def test_parse_quantifier_plus(self):
+        """Test parsing the + quantifier."""
         ast = parse_regex("a+")
         assert len(ast) == 1
         assert isinstance(ast[0], Quantifier)
 
     def test_parse_quantifier_question(self):
+        """Test parsing the ? quantifier."""
         ast = parse_regex("a?")
         assert len(ast) == 1
         assert isinstance(ast[0], Quantifier)
 
     def test_parse_group(self):
+        """Test parsing a group."""
         ast = parse_regex("(abc)")
         assert len(ast) == 1
         assert isinstance(ast[0], Group)
         assert len(ast[0].content) == 1
+        assert isinstance(ast[0].content[0], Literal)
+        assert ast[0].content[0].value == "abc"
 
     def test_parse_non_capturing_group(self):
+        """Test parsing a non-capturing group."""
         ast = parse_regex("(?:abc)")
         assert len(ast) == 1
         assert isinstance(ast[0], Group)
         assert ast[0].capturing is False
 
     def test_parse_alternation(self):
+        """Test parsing alternation."""
         ast = parse_regex("a|b")
         assert len(ast) == 1
         assert isinstance(ast[0], Alternation)
         assert len(ast[0].options) == 2
 
     def test_parse_anchors(self):
+        """Test parsing anchors."""
         ast = parse_regex("^start$")
         assert len(ast) == 3
         assert isinstance(ast[0], Anchor)
+        assert isinstance(ast[1], Literal)
         assert isinstance(ast[2], Anchor)
+        assert ast[1].value == "start"
 
     def test_parse_special_sequences(self):
+        """Test parsing special sequences."""
         ast = parse_regex(r"\d+\w+")
         assert len(ast) == 2
         assert isinstance(ast[0], Quantifier)
+        assert isinstance(ast[1], Quantifier)
 
     def test_parse_complex_pattern(self):
+        """Test parsing a complex pattern."""
         pattern = r"^\w+@[a-z]+\.[a-z]+$"
         ast = parse_regex(pattern)
         assert len(ast) > 0
 
     def test_parse_error_unclosed_bracket(self):
+        """Test parsing error for unclosed bracket."""
         with pytest.raises(ParseError):
             parse_regex("[abc")
 
     def test_parse_error_unclosed_group(self):
+        """Test parsing error for unclosed group."""
         with pytest.raises(ParseError):
             parse_regex("(abc")