From e6df9e7483c44a9ccf4abe000011bd4d7a67db84 Mon Sep 17 00:00:00 2001
From: Hamish Knight <hamish_knight@apple.com>
Date: Wed, 4 Jun 2025 12:32:36 +0100
Subject: [PATCH] Update for new `ExpandEditorPlaceholdersToLiteralClosures`
 API

This refactoring now takes a `Syntax` parameter. We don't actually
need to change anything else to handle placeholder expansion for
macro expansion completions since they get parsed as function calls.
---
 .../Swift/CodeCompletionSession.swift         |  5 +-
 .../SwiftCompletionTests.swift                | 67 +++++++++++++++++++
 2 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/Sources/SourceKitLSP/Swift/CodeCompletionSession.swift b/Sources/SourceKitLSP/Swift/CodeCompletionSession.swift
index 1d77fc41d..d558828b0 100644
--- a/Sources/SourceKitLSP/Swift/CodeCompletionSession.swift
+++ b/Sources/SourceKitLSP/Swift/CodeCompletionSession.swift
@@ -405,11 +405,14 @@ class CodeCompletionSession {
       exprToExpand = insertText
     }
 
+    // Note we don't need special handling for macro expansions since
+    // their insertion text doesn't include the '#', so are parsed as
+    // function calls here.
     var parser = Parser(exprToExpand)
     let expr = ExprSyntax.parse(from: &parser)
     guard let call = OutermostFunctionCallFinder.findOutermostFunctionCall(in: expr),
       let expandedCall = ExpandEditorPlaceholdersToLiteralClosures.refactor(
-        syntax: call,
+        syntax: Syntax(call),
         in: ExpandEditorPlaceholdersToLiteralClosures.Context(
           format: .custom(
             ClosureCompletionFormat(indentationWidth: indentationWidth),
diff --git a/Tests/SourceKitLSPTests/SwiftCompletionTests.swift b/Tests/SourceKitLSPTests/SwiftCompletionTests.swift
index 26cd1628d..d08e0233c 100644
--- a/Tests/SourceKitLSPTests/SwiftCompletionTests.swift
+++ b/Tests/SourceKitLSPTests/SwiftCompletionTests.swift
@@ -1058,6 +1058,73 @@ final class SwiftCompletionTests: XCTestCase {
     )
   }
 
+  func testExpandMacroClosurePlaceholder() async throws {
+    try await SkipUnless.sourcekitdSupportsPlugin()
+
+    let testClient = try await TestSourceKitLSPClient(capabilities: snippetCapabilities)
+    let uri = DocumentURI(for: .swift)
+    let positions = testClient.openDocument(
+      """
+      @freestanding(expression)
+      macro myMacroExpr(fn: (Int) -> String) = #externalMacro(module: "", type: "")
+
+      @freestanding(declaration)
+      macro myMacroDecl(fn1: (Int) -> String, fn2: () -> Void) = #externalMacro(module: "", type: "")
+
+      func test() {
+          #1️⃣
+      }
+      """,
+      uri: uri
+    )
+    let completions = try await testClient.send(
+      CompletionRequest(textDocument: TextDocumentIdentifier(uri), position: positions["1️⃣"])
+    )
+    XCTAssertEqual(
+      completions.items.clearingUnstableValues.filter { $0.label.contains("myMacro") },
+      [
+        CompletionItem(
+          label: "myMacroDecl(fn1: (Int) -> String, fn2: () -> Void)",
+          kind: .value,
+          detail: "Declaration Macro",
+          deprecated: false,
+          filterText: "myMacroDecl(fn1:fn2:)",
+          insertText: #"""
+            myMacroDecl(fn1: ${1:{ ${2:Int} in ${3:String} \}}, fn2: ${4:{ ${5:Void} \}})
+            """#,
+          insertTextFormat: .snippet,
+          textEdit: .textEdit(
+            TextEdit(
+              range: Range(positions["1️⃣"]),
+              newText: #"""
+                myMacroDecl(fn1: ${1:{ ${2:Int} in ${3:String} \}}, fn2: ${4:{ ${5:Void} \}})
+                """#
+            )
+          )
+        ),
+        CompletionItem(
+          label: "myMacroExpr(fn: (Int) -> String)",
+          kind: .value,
+          detail: "Void",
+          deprecated: false,
+          filterText: "myMacroExpr(fn:)",
+          insertText: #"""
+            myMacroExpr(fn: ${1:{ ${2:Int} in ${3:String} \}})
+            """#,
+          insertTextFormat: .snippet,
+          textEdit: .textEdit(
+            TextEdit(
+              range: Range(positions["1️⃣"]),
+              newText: #"""
+                myMacroExpr(fn: ${1:{ ${2:Int} in ${3:String} \}})
+                """#
+            )
+          )
+        ),
+      ]
+    )
+  }
+
   func testCompletionScoring() async throws {
     try await SkipUnless.sourcekitdSupportsPlugin()