Merge pull request #936 from ahoppen/ahoppen/review-comments

Address review comments

Author: ahoppen

Sources/SwiftParser/Diagnostics/ParseDiagnosticsGenerator.swift

@@ -464,7 +464,11 @@ public class ParseDiagnosticsGenerator: SyntaxAnyVisitor {
       return .skipChildren
     }
     if node.expression.is(MissingExprSyntax.self) {
-      addDiagnostic(node.expression, .expectedExpressionAfterTry, handledNodes: [node.expression.id])
+      addDiagnostic(node.expression, .expectedExpressionAfterTry, fixIts: [
+        FixIt(message: InsertTokenFixIt(missingNodes: [Syntax(node.expression)]), changes: [
+          .makePresent(node: node.expression)
+        ])
+      ], handledNodes: [node.expression.id])
     }
     return .visitChildren
   }

Sources/SwiftSyntax/Syntax.swift

@@ -225,6 +225,8 @@ public extension SyntaxProtocol {
       return nil
     }
     let siblings = NonNilRawSyntaxChildren(parent, viewMode: viewMode)
+    // `self` could be a missing node at index 0 and `viewMode` be `.sourceAccurate`.
+    // In that case `siblings` skips over the missing `self` node and has a `startIndex > 0`.
     if self.index >= siblings.startIndex {
       for absoluteRaw in siblings[..<self.index].reversed() {
         let child = Syntax(SyntaxData(absoluteRaw, parent: parent))

Tests/SwiftParserTest/translated/TryTests.swift

@@ -266,8 +266,8 @@ final class TryTests: XCTestCase {
       """,
       diagnostics: [
         DiagnosticSpec(locationMarker: "1️⃣", message: "'try' must be placed on the thrown expression", fixIts: ["move 'try' after 'throw'"]),
-        DiagnosticSpec(locationMarker: "2️⃣", message: "expected expression after 'try'"),
-      ], fixedSource: "throw try"
+        DiagnosticSpec(locationMarker: "2️⃣", message: "expected expression after 'try'", fixIts: ["insert expression"]),
+      ], fixedSource: "throw try <#expression#>"
     )
   }