MCP Email Service

""" Regression test for unknown-8bit encoding issue Tests that emails with non-standard charsets like 'unknown-8bit' are handled gracefully. """ import sys import os sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))) from src.legacy_operations import decode_mime_words import email def test_unknown_8bit_encoding(): """Test handling of 'unknown-8bit' charset in MIME headers""" # Simulate a header with unknown-8bit encoding test_cases = [ ("=?unknown-8bit?Q?Test_Subject?=", "Test Subject"), ("=?unknown-8bit?B?VGVzdCBTdWJqZWN0?=", "Test Subject"), ("=?x-unknown?Q?Another_Test?=", "Another Test"), ("=?8bit?Q?Simple?=", "Simple"), ("=?unknown?Q?Fallback?=", "Fallback"), ] for encoded_header, expected_text in test_cases: result = decode_mime_words(encoded_header) assert expected_text in result, f"Failed to decode '{encoded_header}', got '{result}'" print(f"✓ Decoded '{encoded_header}' -> '{result}'") def test_mixed_valid_and_unknown_encoding(): """Test headers with both valid and unknown encodings""" # Mix of UTF-8 and unknown-8bit test_header = "=?utf-8?Q?Valid_Part?= =?unknown-8bit?Q?_Unknown_Part?=" result = decode_mime_words(test_header) assert "Valid Part" in result assert "Unknown Part" in result print(f"✓ Mixed encoding decoded: '{result}'") def test_unknown_encoding_with_special_chars(): """Test unknown encoding with special characters that might fail""" # Test headers with special characters in unknown-8bit encoding test_cases = [ "=?unknown-8bit?Q?Caf=E9?=", # café in latin-1 "=?unknown-8bit?B?VMOpcw==?=", # Test in base64 "=?x-unknown?Q?R=E9sum=E9?=", # Résumé ] for header in test_cases: result = decode_mime_words(header) assert len(result) > 0, f"Failed to decode '{header}'" print(f"✓ Special chars decoded successfully") def test_completely_invalid_charset(): """Test a charset that doesn't exist at all""" # Test with a completely made-up charset # decode_mime_words should handle it gracefully with fallback test_header = "=?nonexistent-charset-xyz?Q?Test_content?=" result = decode_mime_words(test_header) # Should not crash, should return something assert result is not None assert len(result) > 0 print(f"✓ Invalid charset handled: '{result}'") def test_empty_and_none_values(): """Test edge cases with empty or None values""" assert decode_mime_words("") == "" assert decode_mime_words(None) == "" # Plain ASCII (no encoding) plain = "Plain ASCII text" assert decode_mime_words(plain) == plain print("✓ Empty and plain values handled correctly") def test_real_world_unknown_8bit_email(): """Test a realistic email with unknown-8bit encoding""" # Create a minimal email with unknown-8bit in Content-Type raw_email = b"""From: sender@example.com To: recipient@example.com Subject: =?unknown-8bit?Q?Test_Subject?= Content-Type: text/plain; charset="unknown-8bit" Test body content """ # Parse the email msg = email.message_from_bytes(raw_email) # Decode the subject using our function subject = decode_mime_words(msg.get('Subject', '')) assert "Test Subject" in subject print(f"✓ Real-world email parsed successfully, subject: '{subject}'") if __name__ == '__main__': print("=" * 60) print("Testing unknown-8bit encoding handling") print("=" * 60) test_unknown_8bit_encoding() test_mixed_valid_and_unknown_encoding() test_unknown_encoding_with_special_chars() test_completely_invalid_charset() test_empty_and_none_values() test_real_world_unknown_8bit_email() print("=" * 60) print("✅ All tests passed!") print("=" * 60)