Merge pull request #1111 from ahoppen/ahoppen/infer-closure-indentation

Infer indentation of the current source file when expanding trailing closures 🚥 #1110

Author: ahoppen

Package.swift

@@ -293,6 +293,7 @@ let package = Package(
         "SKSwiftPMWorkspace",
         "SourceKitD",
         .product(name: "IndexStoreDB", package: "indexstore-db"),
+        .product(name: "SwiftBasicFormat", package: "swift-syntax"),
         .product(name: "SwiftDiagnostics", package: "swift-syntax"),
         .product(name: "SwiftIDEUtils", package: "swift-syntax"),
         .product(name: "SwiftParser", package: "swift-syntax"),

Sources/SourceKitLSP/Swift/CodeCompletion.swift

@@ -14,6 +14,7 @@ import Foundation
 import LSPLogging
 import LanguageServerProtocol
 import SourceKitD
+import SwiftBasicFormat
 
 extension SwiftLanguageServer {
 
@@ -43,10 +44,13 @@ extension SwiftLanguageServer {
     let clientSupportsSnippets =
       capabilityRegistry.clientCapabilities.textDocument?.completion?.completionItem?.snippetSupport ?? false
     let buildSettings = await buildSettings(for: snapshot.uri)
+
+    let inferredIndentationWidth = BasicFormat.inferIndentation(of: await syntaxTreeManager.syntaxTree(for: snapshot))
+
     return try await CodeCompletionSession.completionList(
       sourcekitd: sourcekitd,
       snapshot: snapshot,
-      syntaxTreeParseResult: syntaxTreeManager.incrementalParseResult(for: snapshot),
+      indentationWidth: inferredIndentationWidth,
       completionPosition: completionPos,
       completionUtf8Offset: offset,
       cursorPosition: req.position,

Sources/SourceKitLSP/Swift/CodeCompletionSession.swift

@@ -91,7 +91,7 @@ class CodeCompletionSession {
   static func completionList(
     sourcekitd: any SourceKitD,
     snapshot: DocumentSnapshot,
-    syntaxTreeParseResult: IncrementalParseResult,
+    indentationWidth: Trivia?,
     completionPosition: Position,
     completionUtf8Offset: Int,
     cursorPosition: Position,
@@ -123,7 +123,7 @@ class CodeCompletionSession {
       let session = CodeCompletionSession(
         sourcekitd: sourcekitd,
         snapshot: snapshot,
-        syntaxTreeParseResult: syntaxTreeParseResult,
+        indentationWidth: indentationWidth,
         utf8Offset: completionUtf8Offset,
         position: completionPosition,
         compileCommand: compileCommand,
@@ -140,7 +140,8 @@ class CodeCompletionSession {
 
   private let sourcekitd: any SourceKitD
   private let snapshot: DocumentSnapshot
-  private let syntaxTreeParseResult: IncrementalParseResult
+  /// The inferred indentation width of the source file the completion is being performed in
+  private let indentationWidth: Trivia?
   private let utf8StartOffset: Int
   private let position: Position
   private let compileCommand: SwiftCompileCommand?
@@ -158,14 +159,14 @@ class CodeCompletionSession {
   private init(
     sourcekitd: any SourceKitD,
     snapshot: DocumentSnapshot,
-    syntaxTreeParseResult: IncrementalParseResult,
+    indentationWidth: Trivia?,
     utf8Offset: Int,
     position: Position,
     compileCommand: SwiftCompileCommand?,
     clientSupportsSnippets: Bool
   ) {
     self.sourcekitd = sourcekitd
-    self.syntaxTreeParseResult = syntaxTreeParseResult
+    self.indentationWidth = indentationWidth
     self.snapshot = snapshot
     self.utf8StartOffset = utf8Offset
     self.position = position
@@ -308,7 +309,10 @@ class CodeCompletionSession {
     var parser = Parser(exprToExpand)
     let expr = ExprSyntax.parse(from: &parser)
     guard let call = OutermostFunctionCallFinder.findOutermostFunctionCall(in: expr),
-      let expandedCall = ExpandEditorPlaceholdersToTrailingClosures.refactor(syntax: call)
+      let expandedCall = ExpandEditorPlaceholdersToTrailingClosures.refactor(
+        syntax: call,
+        in: ExpandEditorPlaceholdersToTrailingClosures.Context(indentationWidth: indentationWidth)
+      )
     else {
       return nil
     }

Tests/SourceKitLSPTests/SwiftCompletionTests.swift

@@ -1025,6 +1025,7 @@ final class SwiftCompletionTests: XCTestCase {
       ]
     )
   }
+
   func testExpandClosurePlaceholderOnOptional() async throws {
     let testClient = try await TestSourceKitLSPClient(capabilities: snippetCapabilities)
     let uri = DocumentURI.for(.swift)
@@ -1176,6 +1177,56 @@ final class SwiftCompletionTests: XCTestCase {
       ]
     )
   }
+
+  func testInferIndentationWhenExpandingClosurePlaceholder() async throws {
+    let testClient = try await TestSourceKitLSPClient(capabilities: snippetCapabilities)
+    let uri = DocumentURI.for(.swift)
+    let positions = testClient.openDocument(
+      """
+      struct MyArray {
+        func myMap(_ body: (Int) -> Bool) -> Int {
+          return 1
+        }
+      }
+      func test(x: MyArray) {
+        x.1️⃣
+      }
+      """,
+      uri: uri
+    )
+    let completions = try await testClient.send(
+      CompletionRequest(textDocument: TextDocumentIdentifier(uri), position: positions["1️⃣"])
+    )
+    XCTAssertEqual(
+      completions.items.filter { $0.label.contains("myMap") },
+      [
+        CompletionItem(
+          label: "myMap(body: (Int) -> Bool)",
+          kind: .method,
+          detail: "Int",
+          deprecated: false,
+          sortText: nil,
+          filterText: "myMap(:)",
+          insertText: """
+            myMap { ${1:Int} in
+                ${2:Bool}
+              }
+            """,
+          insertTextFormat: .snippet,
+          textEdit: .textEdit(
+            TextEdit(
+              range: Range(positions["1️⃣"]),
+              newText: """
+                myMap { ${1:Int} in
+                    ${2:Bool}
+                  }
+                """
+            )
+          )
+        )
+      ]
+    )
+  }
 }
 
 private func countFs(_ response: CompletionList) -> Int {