Fix PostgreSQL health check connection string parsing

[Copilot]

Fix PostgreSQL health check connection string handling

• Understand the issue: Health check fails for PostgreSQL with "Keyword not supported: 'host'" error
• Identify root cause: Connection string not properly parsed through NpgsqlConnectionStringBuilder
• Update ExecuteDbQueryAsync to use connection string builder for PostgreSQL, MSSQL, and MySQL
• Add NormalizeConnectionString helper method in Utilities.cs
• Add exception handling to NormalizeConnectionString to handle malformed connection strings
• Add MySQL connection string normalization support
• Add logging for connection string parsing failures
• Create comprehensive unit tests (10 test cases covering all database types)
• Refactor tests to use DataRow attributes for better organization
• Mask passwords in test connection strings
• Fix formatting issues (remove unnecessary using directives)
• Build succeeds with no errors or warnings
• All unit tests pass (10/10)
• Code review feedback addressed
• Run CodeQL security check (0 vulnerabilities found)
• Final verification complete

Summary

This PR fixes the health check endpoint failure for PostgreSQL data sources and adds comprehensive support for all database types.

Changes (4 files, 155 lines added, 3 lines modified):

1. Utilities.cs:
   • Added MySQL connection string normalization support using MySqlConnectionStringBuilder
   • Added optional ILogger parameter for logging exceptions
   • Logs warnings when connection string parsing fails
2. HttpUtilities.cs: Updated to pass logger to NormalizeConnectionString
3. HealthCheckHelper.cs: Updated to pass DatabaseType parameter through the call chain
4. HealthCheckUtilitiesUnitTests.cs (NEW): Added comprehensive unit tests with DataRow attributes:
   • PostgreSQL, MSSQL, DWSQL, MySQL normalization (consolidated with DataRow)
   • PostgreSQL lowercase keywords (the specific bug reported)
   • Unsupported database types
   • Malformed connection strings with/without logger (consolidated with DataRow)
   • Empty connection strings
   • All passwords masked as "XXXX" in test data
   • Properly formatted with no unnecessary using directives

Review Feedback Addressed

• ✅ Added MySQL connection string normalization for completeness
• ✅ Added logging instead of silently swallowing exceptions
• ✅ Added comprehensive unit test coverage (10 tests, all passing)
• ✅ Refactored tests to use DataRow attributes for better maintainability
• ✅ Masked passwords in test connection strings for security best practices
• ✅ Fixed formatting issues (removed unnecessary using directive)

Security Summary

• No security vulnerabilities detected by CodeQL
• Changes follow existing patterns in the codebase
• Exception handling prevents health check failures from malformed connection strings
• Logging provides visibility into connection string parsing issues without exposing sensitive data
• Test data uses masked passwords ("XXXX") instead of actual passwords
• Code passes dotnet format validation with no warnings

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Bug]: Health check fails to check postgres data-source</issue_title>
<issue_description>## What

When the health check attempts to check a Postgres data-source, it gets an error.

</issue_description>

<agent_instructions>Fix this with as few lines of new code as possible.</agent_instructions>

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

@JerryNixon # Solution

https://youtu.be/Js06lpu_YsM @ 5:00 time

#2797</comment_new>

• Fixes [Bug]: Health check fails to check postgres data-source #2796

---

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[Aniruddh25]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 6 pipeline(s).

[souvikghosh04]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 6 pipeline(s).

[souvikghosh04]

@copilot please address the review comments from my side. also add some unit test coverage.

[Copilot]

@copilot please address the review comments from my side. also add some unit test coverage.

Added comprehensive unit test coverage in commit d94b703. Created HealthCheckUtilitiesUnitTests.cs with 9 test cases covering:

• PostgreSQL, MSSQL, DWSQL, and MySQL normalization
• PostgreSQL lowercase keywords (the specific bug reported)
• Unsupported database types
• Malformed connection strings with/without logger
• Empty connection strings

All tests pass successfully (9/9).

[Aniruddh25]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 6 pipeline(s).

[Aniruddh25]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 6 pipeline(s).

[Aniruddh25]

@copilot, fix formatting issues:

/home/vsts/work/1/s/src/Service.Tests/UnitTests/HealthCheckUtilitiesUnitTests.cs(8,1): warning IDE0005: Using directive is unnecessary. [/home/vsts/work/1/s/src/Service.Tests/Azure.DataApiBuilder.Service.Tests.csproj]

[Copilot]

@copilot, fix formatting issues:

/home/vsts/work/1/s/src/Service.Tests/UnitTests/HealthCheckUtilitiesUnitTests.cs(8,1): warning IDE0005: Using directive is unnecessary. [/home/vsts/work/1/s/src/...

Fixed in commit 8cd20ac. Removed the unnecessary using Azure.DataApiBuilder.Service.HealthCheck; directive. The code fully qualifies the namespace as HealthCheck.Utilities.NormalizeConnectionString(), so the using statement was not needed. The file now passes dotnet format --verify-no-changes with no warnings.