Support ranged CollectVariableType requests

Author: fwcd

Sources/SourceKitLSP/Swift/SwiftLanguageServer.swift

@@ -1061,16 +1061,12 @@ extension SwiftLanguageServer {
     }
 
     let uri = req.params.textDocument.uri
-    variableTypeInfos(uri) { infosResult in
+    variableTypeInfos(uri, req.params.range) { infosResult in
       do {
         let infos = try infosResult.get()
         let hints = infos
           .lazy
-          .filter { info in
-            // TODO: Include range in CollectVariableType request directly
-            (req.params.range?.contains(info.range.upperBound) ?? true)
-            && !info.hasExplicitType
-          }
+          .filter { !$0.hasExplicitType }
           .map { info in
             InlayHint(
               position: info.range.upperBound,

Sources/SourceKitLSP/Swift/VariableTypeInfo.swift

@@ -53,6 +53,7 @@ extension SwiftLanguageServer {
   /// Must be called on self.queue.
   private func _variableTypeInfos(
     _ uri: DocumentURI,
+    _ range: Range<Position>? = nil,
     _ completion: @escaping (Swift.Result<[VariableTypeInfo], VariableTypeInfoError>) -> Void
   ) {
     dispatchPrecondition(condition: .onQueue(queue))
@@ -67,6 +68,13 @@ extension SwiftLanguageServer {
     skreq[keys.request] = requests.variable_type
     skreq[keys.sourcefile] = snapshot.document.uri.pseudoPath
 
+    if let range = range,
+       let start = snapshot.utf8Offset(of: range.lowerBound),
+       let end = snapshot.utf8Offset(of: range.upperBound) {
+      skreq[keys.offset] = start
+      skreq[keys.length] = end - start
+    }
+
     // FIXME: SourceKit should probably cache this for us
     if let compileCommand = self.commandsByFile[uri] {
       skreq[keys.compilerargs] = compileCommand.compilerArgs
@@ -107,10 +115,11 @@ extension SwiftLanguageServer {
   ///   - completion: Completion block to asynchronously receive the VariableTypeInfos, or error.
   func variableTypeInfos(
     _ uri: DocumentURI,
+    _ range: Range<Position>? = nil,
     _ completion: @escaping (Swift.Result<[VariableTypeInfo], VariableTypeInfoError>) -> Void
   ) {
     queue.async {
-      self._variableTypeInfos(uri, completion)
+      self._variableTypeInfos(uri, range, completion)
     }
   }
 }