FIX: Update escaping rules in connection string parser and builder

[saurabh500]

Work Item / Issue Reference

GitHub Issue: #363

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Summary

FIX: The escaping rules for the parser and the builder

The parser was treating {{ as an escaped string and was parsing it as { and then the builder was escaping { to {{
However the ODBC driver doesn't require escaping of the opening brace, if its already wrapped in {}. Only closing brace values inside curlies require escaping. Hence a literal pw}d needs to be sent as {pw}}d}

Fixed the parser and the builder to take care of this nuance.

Fixes #363

[github-actions]

📊 Code Coverage Report

🔥 Diff Coverage 100%

🎯 Overall Coverage 75%

📈 Total Lines Covered: 5088 out of 6751 📁 Project: mssql-python

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Diff Coverage

Diff: main...HEAD, staged and unstaged changes

• mssql_python/connection_string_builder.py (100%)

Summary

• Total: 1 line
• Missing: 0 lines
• Coverage: 100%

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📋 Files Needing Attention

📉 Files with overall lowest coverage (click to expand)

mssql_python.pybind.logger_bridge.cpp: 59.2%
mssql_python.row.py: 66.2%
mssql_python.pybind.ddbc_bindings.cpp: 67.1%
mssql_python.helpers.py: 67.5%
mssql_python.pybind.connection.connection.cpp: 73.6%
mssql_python.pybind.ddbc_bindings.h: 76.9%
mssql_python.ddbc_bindings.py: 79.6%
mssql_python.pybind.connection.connection_pool.cpp: 79.6%
mssql_python.connection.py: 82.5%
mssql_python.cursor.py: 83.8%

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[Copilot]

Pull request overview

This PR fixes the ODBC connection string escaping rules in the parser and builder to correctly align with the MS-ODBCSTR specification. The key issue was that the code was treating {{ as an escape sequence for {, when in fact only closing braces } need escaping (as }}). Opening braces { should be kept as literal characters within braced values.

Key Changes:

• Updated parser to not treat {{ as an escape sequence, keeping it as literal {{
• Updated builder to only escape closing braces } → }}, removed escaping of opening braces
• Updated all affected tests to reflect the corrected behavior

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
mssql_python/connection_string_parser.py	Removed logic that treated {{ as an escape sequence in _parse_braced_value(), updated comments and docstrings to clarify only } needs escaping
mssql_python/connection_string_builder.py	Removed .replace("{", "{{") from _escape_value(), updated docstrings and examples to reflect only closing braces need escaping
tests/test_010_connection_string_parser.py	Updated test assertions and docstrings to expect {{ as literal characters rather than escaped {, covering multiple test cases including edge cases

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[jahnvi480]

LGTM

[bewithgaurav]

lgtm

[saurabh500]

Waiting for alpine build issues to be solved which is a blocker for merge. Coordination with odbc team in progress