Handle 'reasync' In Function Signatures

Author: CodaFi

Sources/SwiftParser/Declarations.swift

@@ -1412,7 +1412,14 @@ extension Parser {
   public mutating func parseFunctionSignature() -> RawFunctionSignatureSyntax {
     let input = self.parseParameterClause(for: .functionParameters)
 
-    let async = self.consumeIfContextualKeyword("async")
+    let async: RawTokenSyntax?
+    if let asyncTok = self.consumeIfContextualKeyword("async") {
+      async = asyncTok
+    } else if let reasync = self.consumeIfContextualKeyword("reasync") {
+      async = reasync
+    } else {
+      async = nil
+    }
 
     var throwsKeyword = self.consume(ifAny: [.throwsKeyword, .rethrowsKeyword])
 

Tests/SwiftParserTest/Declarations.swift

@@ -1005,6 +1005,21 @@ final class DeclarationTests: XCTestCase {
       func isolatedConst(isolated _const: String) {}
       """#)
   }
+
+  func testReasyncFunctions() throws {
+    AssertParse(
+      """
+      class MyType {
+        init(_ f: () async -> Void) reasync {
+          await f()
+        }
+
+        func foo(index: Int) reasync rethrows -> String {
+          await f()
+        }
+      }
+      """)
+  }
 }
 
 extension Parser.DeclAttributes {