Summary

• Add T-SQL v170 AST validation for the fourth VECTOR_DISTANCE argument.
• Report parse error 46146 when an integer dimension is outside the valid range of 1 through 1984.
• Add an MSTest regression test for an invalid dimension of 0.

Implementation

• Add Sql170ExpressionVisitor to inspect VECTOR_DISTANCE function calls.
• Validate literal dimensions using invariant int.TryParse and C# pattern matching.
• Run the visitor from TSql170Parser after parsing.
• Return: Vector dimension must be an integer between 1 and 1984.

TDD Evidence

• RED: With the visitor hook disabled, the focused test failed 1/1 at errors.Count > 0 because the parser returned no errors.
• GREEN: With the visitor enabled, the same focused test passed 1/1.

Testing

Passed:

dotnet test Test/SqlDom/UTSqlScriptDom.csproj -c Debug -f net8.0 --filter "FullyQualifiedName~TestVectorDistance_InvalidDimension_ShouldReturnParseError"

The full net8.0 suite was started but canceled after test discovery. No test failure was reported before cancellation.

Code Changes

• Unit tests are added, if possible
• Existing tests are passing
• New or updated code follows the guidelines here