Escape XML special characters in XSLT transformation enum values

[Copilot]

Fix Transformation Generator Special Character Escaping

This PR fixes the issue where the transformation generator does not properly escape special XML characters in enum values.

Progress:

• Explore the repository structure and understand the codebase
• Run existing tests to establish baseline
• Create test case with enum values containing special characters (< and >)
• Implement XML escaping function for enum values
• Apply escaping in get_abap_value method
• Fix escape order to prevent double-escaping
• Run tests to verify the fix
• Lint code to ensure no syntax errors
• Add integration test for struc_with_special_char_enums

Technical Details:

The issue occurs in zcl_aff_writer_xslt.clas.abap where enum values are written to the XSLT transformation without proper XML escaping.

Changes made:

1. Added escape_xml_chars method to escape special XML characters:

   • & → & (escaped first to prevent double-escaping)
   • < → <
   • > → >
   • " → "
   • ' → '

2. Modified get_abap_value method to apply escaping to character and numeric text values

3. Added test case struc_with_special_char_enums to verify the fix works correctly with enum values containing <, >, and &

4. Added integration test in ltcl_integration_test_ad that tests the round-trip serialization/deserialization of special character enum values

The fix ensures that enum values with special XML characters are properly escaped in the generated XSLT transformation, preventing XML syntax errors. The ampersand is escaped first to avoid double-escaping of the escape sequences themselves.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Transformation Generator does not escape special characters</issue_title>
<issue_description>XML cannot handle special characters such as '<' and '>'. The generator does not escape these characters which leads to syntax errors in the generated transformation when having an enum/constant like

begin of co_enum_values
   less_than type c length 1 value '<',
   greater_thean type c length 1 value '>',
end of co_enum_values.

A solution would be to replace < with &#60 and > with &#62 in the generated transformation. </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Transformation Generator does not escape special characters #319

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[wurzka]

Integration test missing

[wurzka]

Integration test in ltcl_integration_test_ad missing

[Markus1812]

Integration test in ltcl_integration_test_ad missing

@copilot

[Copilot]

Added integration test struc_with_special_char_enums in ltcl_integration_test_ad that tests round-trip serialization/deserialization for all three special characters (<, >, &). Commit: 5fb3ed0

[Copilot]

Integration test missing

Added integration test struc_with_special_char_enums in ltcl_integration_test_ad that tests round-trip serialization/deserialization for all three special characters (<, >, &). Commit: 5fb3ed0

[schneidermic0]

Can't we use ABAP's built-in function escape to escape xml?

See https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/ABENESCAPE_FUNCTIONS.html