Check parents for childNameForDiagnostics

Author: ahoppen

Sources/SwiftParser/Diagnostics/MissingNodesError.swift

@@ -42,11 +42,19 @@ fileprivate enum NodesDescriptionPart {
       }
       return token.tokenKind.decomposeToRaw().rawKind.nameForDiagnostics
     case .node(let node):
-      if let childName = node.childNameInParent {
-        return childName
-      } else {
-        return node.nodeTypeNameForDiagnostics(allowBlockNames: true)
+      var walk: Syntax = node
+      while true {
+        if let childName = walk.childNameInParent {
+          return childName
+        }
+        if let parent = walk.parent, parent.children(viewMode: .all).count == 1 {
+          // If walk is the only node in its parent, check if that parent has a childNameForDiagnostics
+          walk = parent
+        } else {
+          break
+        }
       }
+      return node.nodeTypeNameForDiagnostics(allowBlockNames: true)
     }
   }
 

Tests/SwiftParserTest/translated/GuardTests.swift

@@ -9,18 +9,23 @@ final class GuardTests: XCTestCase {
       func noConditionNoElse() {
         guard {} 1️⃣
       }
-      func noCondition() {
-        guard 2️⃣else {} 
-      }3️⃣
       """,
       diagnostics: [
-        // TODO: Old parser expected error on line 2: missing condition in 'guard' statement
-        // TODO: Old parser expected error on line 2: expected 'else' after 'guard' condition
-        DiagnosticSpec(locationMarker: "1️⃣", message: "expected 'else' and body in 'guard' statement"),
-        // TODO: Old parser expected error on line 5: missing condition in 'guard' statement
-        DiagnosticSpec(locationMarker: "2️⃣", message: "expected expression in 'guard' statement"),
+        DiagnosticSpec(message: "expected 'else' and body in 'guard' statement"),
       ]
     )
   }
 
+  func testGuard2() {
+    AssertParse(
+      """
+      func noCondition() {
+        guard 1️⃣else {}
+      }
+      """,
+      diagnostics: [
+        DiagnosticSpec(message: "expected conditions in 'guard' statement"),
+      ]
+    )
+  }
 }