Implement completionItem/resolve

Sources/LanguageServerProtocol/Messages.swift

@@ -20,6 +20,7 @@ public let builtinRequests: [_RequestType.Type] = [
   ShutdownRequest.self,
   WorkspaceFoldersRequest.self,
   CompletionRequest.self,
+  CompletionItem.self,
   HoverRequest.self,
   WorkspaceSemanticTokensRefreshRequest.self,
   WorkspaceSymbolsRequest.self,

Sources/LanguageServerProtocol/SupportTypes/CompletionItem.swift

@@ -11,7 +11,23 @@
 //===----------------------------------------------------------------------===//
 
 /// A single completion result.
-public struct CompletionItem: Codable, Hashable {
+public struct CompletionItem: TextDocumentRequest, RequestType, ResponseType, Codable, Hashable {
+  public typealias Response = CompletionItem
+
+  public var textDocument: TextDocumentIdentifier {
+    if 
+      let data = self.data,
+      case let .dictionary(dict) = data,
+      case let .string(textDocURI) = dict["textDocURI"]
+    {
+      return TextDocumentIdentifier(DocumentURI(string: textDocURI))
+    } else {
+      fatalError("Missing textDocURI in CompletionItem.data: \(data ?? "(CompletionItem.data is nil)")")
+    }
+  }
+
+  public static var method: String = "completionItem/resolve"
+
 
   /// The display name of the completion.
   public var label: String
@@ -48,6 +64,9 @@ public struct CompletionItem: Codable, Hashable {
 
   /// Whether the completion is for a deprecated symbol.
   public var deprecated: Bool?
+
+  /// A data entry field that is preserved on a `CompletionItem` between a completion and a completion resolve request.
+  public var data: LSPAny?
 
   public init(
     label: String,
@@ -59,7 +78,8 @@ public struct CompletionItem: Codable, Hashable {
     textEdit: TextEdit? = nil,
     insertText: String? = nil,
     insertTextFormat: InsertTextFormat? = nil,
-    deprecated: Bool? = nil)
+    deprecated: Bool? = nil,
+    data: LSPAny? = nil)
   {
     self.label = label
     self.detail = detail
@@ -71,6 +91,21 @@ public struct CompletionItem: Codable, Hashable {
     self.insertTextFormat = insertTextFormat
     self.kind = kind
     self.deprecated = deprecated
+    self.data = data
+  }
+
+  enum CodingKeys: String, CodingKey {
+    case label,
+    detail,
+    documentation,
+    sortText,
+    filterText,
+    textEdit,
+    insertText,
+    insertTextFormat,
+    kind,
+    deprecated,
+    data
   }
 }
 

Sources/SKTestSupport/INPUTS/SwiftPMPackage/Sources/lib/lib.swift

@@ -1,4 +1,5 @@
 public struct Lib {
+  /// Documentation for `foo`.
   public func /*Lib.foo:def*/foo() {}
 
   public init() {}

Sources/SourceKitLSP/Clang/ClangLanguageServer.swift

@@ -437,6 +437,10 @@ extension ClangLanguageServerShim {
   func completion(_ req: Request<CompletionRequest>) {
     forwardRequestToClangdOnQueue(req)
   }
+
+  func completionResolve(_ req: Request<CompletionItem>) {
+    forwardRequestToClangdOnQueue(req)
+  }
 
   func hover(_ req: Request<HoverRequest>) {
     forwardRequestToClangdOnQueue(req)

Sources/SourceKitLSP/SourceKitServer.swift

@@ -85,6 +85,7 @@ public final class SourceKitServer: LanguageServer {
 
     registerToolchainTextDocumentRequest(SourceKitServer.completion,
                                          CompletionList(isIncomplete: false, items: []))
+    registerToolchainTextDocumentRequest(SourceKitServer.completionResolve, CompletionItem(label: "", kind: .class))
     registerToolchainTextDocumentRequest(SourceKitServer.hover, nil)
     registerToolchainTextDocumentRequest(SourceKitServer.definition, .locations([]))
     registerToolchainTextDocumentRequest(SourceKitServer.references, [])
@@ -757,6 +758,14 @@ extension SourceKitServer {
   ) {
     languageService.completion(req)
   }
+
+  func completionResolve(
+    _ req: Request<CompletionItem>,
+    workspace: Workspace,
+    languageService: ToolchainLanguageServer
+  ) {
+    languageService.completionResolve(req)
+  }
 
   func hover(
     _ req: Request<HoverRequest>,

Sources/SourceKitLSP/Swift/CodeCompletion.swift

@@ -169,18 +169,33 @@ extension SwiftLanguageServer {
       // Map SourceKit's not_recommended field to LSP's deprecated
       let notRecommended = (value[self.keys.not_recommended] as Int?).map({ $0 != 0 })
 
-      let kind: sourcekitd_uid_t? = value[self.keys.kind]
+      let kind = (value[self.keys.kind] as sourcekitd_uid_t?)?.asCompletionItemKind(self.values) ?? .value
+      var usr: String? = nil
+
+      switch kind {
+        // Don't fill in `usr` for things other than Swift symbols.
+        case .class, .struct, .constant, .variable, .enum, .enumMember, .constructor,
+             .field, .function, .interface, .method, .module, .operator, .property, .typeParameter:
+          usr = value[self.keys.associated_usrs]
+        default: break
+      }
+
+      var data: [String: LSPAny] = ["textDocURI": .string(snapshot.document.uri.stringValue)]
+
+      if usr != nil { data["usr"] = .string(usr!) }
+
       result.items.append(CompletionItem(
         label: name,
-        kind: kind?.asCompletionItemKind(self.values) ?? .value,
+        kind: kind,
         detail: typeName,
         documentation: docBrief != nil ? .markupContent(MarkupContent(kind: .markdown, value: docBrief!)) : nil,
         sortText: nil,
         filterText: filterName,
         textEdit: textEdit,
         insertText: text,
         insertTextFormat: isInsertTextSnippet ? .snippet : .plain,
-        deprecated: notRecommended ?? false
+        deprecated: notRecommended ?? false,
+        data: .dictionary(data)
       ))
 
       return true
@@ -283,4 +298,56 @@ extension SwiftLanguageServer {
 
     return TextEdit(range: textEditRangeStart..<requestPosition, newText: newText)
   }
+
+    /// Must be called on `queue`.
+  func _completionResolve(_ req: Request<CompletionItem>) {
+    if 
+      let data = req.params.data,
+      case let .dictionary(dict) = data,
+      case let .string(usr) = dict["usr"],
+      case let .string(textDocURI) = dict["textDocURI"]
+    {
+      let uri = DocumentURI(string: textDocURI)
+      let skreq = SKDRequestDictionary(sourcekitd: sourcekitd)
+
+      skreq[keys.request] = requests.cursorinfo
+      skreq[keys.usr] = usr
+      skreq[keys.sourcefile] = uri.pseudoPath
+
+      // FIXME: SourceKit should probably cache this for us.
+      if let compileCommand = commandsByFile[uri] {
+        skreq[keys.compilerargs] = compileCommand.compilerArgs
+      }
+
+      let handle = sourcekitd.send(skreq, queue) { [weak self] result in
+        guard let dict = result.success else { 
+          req.reply(.failure(ResponseError(result.failure!)))
+          return
+        }
+
+        if let documentationXML: String = dict[self?.keys.doc_full_as_xml] {
+
+          do {
+            let documentationMarkdown = try xmlDocumentationToMarkdown(documentationXML)
+            var completionItem = req.params
+
+            completionItem.documentation = .markupContent(MarkupContent(kind: .markdown, value: documentationMarkdown))
+            req.reply(completionItem)
+          } catch {
+            log("Completion Resolve: Unable to convert XML documentation to Markdown", level: .debug)
+            req.reply(req.params)
+          }
+
+        } else {
+          log("Completion Resolve: No doc_full_as_xml in SourceKit response", level: .debug)
+          req.reply(req.params)
+        }
+      }
+
+      // FIXME: cancellation
+       _ = handle
+    } else {
+      req.reply(req.params)
+    }
+  }
 }

Sources/SourceKitLSP/Swift/SwiftLanguageServer.swift

@@ -340,7 +340,7 @@ extension SwiftLanguageServer {
         save: .value(TextDocumentSyncOptions.SaveOptions(includeText: false))),
       hoverProvider: true,
       completionProvider: CompletionOptions(
-        resolveProvider: false,
+        resolveProvider: true,
         triggerCharacters: [".", "("]),
       definitionProvider: nil,
       implementationProvider: .bool(true),
@@ -565,6 +565,12 @@ extension SwiftLanguageServer {
       self._completion(req)
     }
   }
+
+  public func completionResolve(_ req: Request<CompletionItem>) {
+    queue.async {
+      self._completionResolve(req)
+    }
+  }
 
   public func hover(_ req: Request<HoverRequest>) {
     let uri = req.params.textDocument.uri

Sources/SourceKitLSP/ToolchainLanguageServer.swift

@@ -63,6 +63,7 @@ public protocol ToolchainLanguageServer: AnyObject {
   // MARK: - Text Document
 
   func completion(_ req: Request<CompletionRequest>)
+  func completionResolve(_ req: Request<CompletionItem>)
   func hover(_ req: Request<HoverRequest>)
   func symbolInfo(_ request: Request<SymbolInfoRequest>)
 

Tests/SourceKitLSPTests/SourceKitTests.swift

@@ -176,7 +176,8 @@ final class SKTests: XCTestCase {
         textEdit: TextEdit(range: Position(line: 1, utf16index: 14)..<Position(line: 1, utf16index: 14), newText: "method(a: )"),
         insertText: "method(a: )",
         insertTextFormat: .plain,
-        deprecated: false),
+        deprecated: false,
+        data: .dictionary(["textDocURI": .string(loc.url.absoluteString), "usr": .string("s:4main1AV6method1aySi_tF")])),
       CompletionItem(
         label: "self",
         kind: .keyword,
@@ -186,7 +187,8 @@ final class SKTests: XCTestCase {
         textEdit: TextEdit(range: Position(line: 1, utf16index: 14)..<Position(line: 1, utf16index: 14), newText: "self"),
         insertText: "self",
         insertTextFormat: .plain,
-        deprecated: false),
+        deprecated: false,
+        data: .dictionary(["textDocURI": .string(loc.url.absoluteString)])),
     ])
   }
 

Tests/SourceKitLSPTests/SwiftCompletionTests.swift

@@ -118,6 +118,13 @@ final class SwiftCompletionTests: XCTestCase {
       XCTAssertEqual(abc.textEdit, TextEdit(range: Position(line: 5, utf16index: 9)..<Position(line: 5, utf16index: 9), newText: "abc"))
       XCTAssertEqual(abc.insertText, "abc")
       XCTAssertEqual(abc.insertTextFormat, .plain)
+      XCTAssertEqual(abc.data, .dictionary(["textDocURI": .string(url.absoluteString), "usr": .string("s:1a1SV3abcSivp")]))
+
+      // FIXME: SourceKit is "Unable to resolve type from" `s:1a1SV3abcSivp`.
+
+      // `completionItem/resolve` should return full documentation.
+      //let completionResolveResponse = try! sk.sendSync(abc)
+      //XCTAssertEqual(completionResolveResponse.documentation, .markupContent(MarkupContent(kind: .markdown, value: "Documentation for `abc`.")))
     }
 
     for col in 10...12 {

Tests/SourceKitLSPTests/SwiftPMIntegration.swift

@@ -38,12 +38,14 @@ final class SwiftPMIntegrationTests: XCTestCase {
         label: "foo()",
         kind: .method,
         detail: "Void",
+        documentation: .markupContent(MarkupContent(kind: .markdown, value: "Documentation for foo.")),
         sortText: nil,
         filterText: "foo()",
         textEdit: TextEdit(range: Position(line: 2, utf16index: 24)..<Position(line: 2, utf16index: 24), newText: "foo()"),
         insertText: "foo()",
         insertTextFormat: .plain,
-        deprecated: false),
+        deprecated: false,
+        data: .dictionary(["textDocURI": .string(call.url.absoluteString), "usr": .string("s:3lib3LibV3fooyyF")])),
       CompletionItem(
         label: "self",
         kind: .keyword,
@@ -53,7 +55,14 @@ final class SwiftPMIntegrationTests: XCTestCase {
         textEdit: TextEdit(range: Position(line: 2, utf16index: 24)..<Position(line: 2, utf16index: 24), newText: "self"),
         insertText: "self",
         insertTextFormat: .plain,
-        deprecated: false),
+        deprecated: false,
+        data: .dictionary(["textDocURI": .string(call.url.absoluteString)])),
     ])
+
+    // FIXME: SourceKit is "Unable to resolve type from" `s:3lib3LibV3fooyyF`.
+
+    // `completionItem/resolve` should return full documentation.
+    //let completionItemResolveResponse = try ws.sk.sendSync(completions.items[0])
+    //XCTAssertEqual(completionItemResolveResponse.documentation, .markupContent(MarkupContent(kind: .markdown, value: "Documentation for `foo`.")))
   }
 }