Wrap the entire feature under ExperimentalFeatures

Author: lokesh-tr

Sources/SKCore/ExperimentalFeatures.swift

@@ -18,4 +18,7 @@ public enum ExperimentalFeature: String, Codable, Sendable, CaseIterable {
 
   /// Add `--experimental-prepare-for-indexing` to the `swift build` command run to prepare a target for indexing.
   case swiftpmPrepareForIndexing = "swiftpm-prepare-for-indexing"
+
+  /// Enable showing macro expansions via `ShowDocumentRequest`
+  case showMacroExpansions = "show-macro-expansions"
 }

Sources/SourceKitLSP/Swift/SwiftLanguageService.swift

@@ -819,9 +819,18 @@ extension SwiftLanguageService {
 
     var canInlineMacro = false
 
+    let showMacroExpansionsIsEnabled = await self.sourceKitLSPServer?.options.experimentalFeatures.contains(
+      .showMacroExpansions
+    )
+
     var refactorActions = cursorInfoResponse.refactorActions.compactMap {
       let lspCommand = $0.asCommand()
       canInlineMacro = $0.actionString == "source.refactoring.kind.inline.macro"
+
+      if !(showMacroExpansionsIsEnabled != nil && showMacroExpansionsIsEnabled!) {
+        canInlineMacro = false
+      }
+
       return CodeAction(title: $0.title, kind: .refactor, command: lspCommand)
     }
 
@@ -951,7 +960,10 @@ extension SwiftLanguageService {
   public func executeCommand(_ req: ExecuteCommandRequest) async throws -> LSPAny? {
     if let command = req.swiftCommand(ofType: SemanticRefactorCommand.self) {
       return try await semanticRefactoring(command)
-    } else if let command = req.swiftCommand(ofType: ExpandMacroCommand.self) {
+    } else if let command = req.swiftCommand(ofType: ExpandMacroCommand.self),
+      let experimentalFeatures = await self.sourceKitLSPServer?.options.experimentalFeatures,
+      experimentalFeatures.contains(.showMacroExpansions)
+    {
       return try await expandMacro(command)
     } else {
       throw ResponseError.unknown("unknown command \(req.command)")

Tests/SourceKitLSPTests/ExecuteCommandTests.swift

@@ -177,7 +177,8 @@ final class ExecuteCommandTests: XCTestCase {
         }
         """,
       ],
-      manifest: SwiftPMTestProject.macroPackageManifest
+      manifest: SwiftPMTestProject.macroPackageManifest,
+      serverOptions: .init(swiftPublishDiagnosticsDebounceDuration: 0, experimentalFeatures: [.showMacroExpansions])
     )
     try await SwiftPMTestProject.build(at: project.scratchDirectory)