The LSP textDocument/references handler was ignoring the includeDeclaration field in the request context, always returning declarations regardless of client preference.

Related to dotnet/vscode-csharp#6217 (comment)

Changes

Protocol Definition

• Changed ReferenceContext.IncludeDeclaration from bool to bool? to distinguish between "not specified" (null, defaults to true) and "explicitly false"

Handler Implementation

• FindAllReferencesHandler now extracts includeDeclaration from request context and passes it through to FindUsagesLSPContext
• Defaults to true when null or not specified per LSP spec

Context Logic

• FindUsagesLSPContext filters out definitions from results when includeDeclaration is false
• Applied in both OnDefinitionFoundAsync and OnReferencesFoundAsync to handle definitions that would otherwise be reported lazily

Tests

• Added tests for includeDeclaration=true, includeDeclaration=false, and includeDeclaration=null scenarios

Example

// Client requests references without declarations
var referenceParams = new ReferenceParams
{
    Context = new ReferenceContext { IncludeDeclaration = false }
};

// Returns only references, definition is filtered out
var results = await handler.HandleRequestAsync(referenceParams, ...);

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.