Avoid adding diagnostic for array and dictionary when the closing bracket is on a new line

Author: kimdv

Sources/SwiftParser/Types.swift

@@ -1057,20 +1057,23 @@ extension Parser {
         return result
       }
 
-      if self.at(.rightSquareBracket) {
-        let (unexpectedBeforeRSquareBracket, rightSquareBracket) = self.expect(.rightSquareBracket)
+      var lookahead = self.lookahead()
+
+      // If we are at a new line, we cannot assume it's an unfinished dictionary or array.
+      if lookahead.currentToken.isAtStartOfLine {
+        return result
+      }
+
+      if let rightSquareBracket = self.consume(if: .rightSquareBracket) {
         result = RawTypeSyntax(
           RawArrayTypeSyntax(
             leftSquareBracket: missingToken(.leftSquareBracket),
             elementType: result,
-            unexpectedBeforeRSquareBracket,
             rightSquareBracket: rightSquareBracket,
             arena: self.arena
           )
         )
       } else if self.at(.colon) {
-        var lookahead = self.lookahead()
-
         // We only want to continue with a dictionary if we can parse a colon and a simpletype.
         // Otherwise we can get a wrong diagnostic if we get a Python-style function declaration.
         guard lookahead.consume(if: .colon) != nil && lookahead.canParseSimpleType() else {

Tests/SwiftParserTest/translated/RecoveryTests.swift

@@ -1498,6 +1498,18 @@ final class RecoveryTests: XCTestCase {
         line: line
       )
     }
+
+    assertParse(
+      """
+      let a8: Int
+      1️⃣]
+      """,
+      diagnostics: [
+        DiagnosticSpec(
+          message: "extraneous code ']' at top level"
+        )
+      ]
+    )
   }
 
   func testRecovery98b() {
@@ -1527,7 +1539,7 @@ final class RecoveryTests: XCTestCase {
         let a2: 2️⃣String: Int]
         let a3: 3️⃣String: [Int]4️⃣
         let a4: 5️⃣String: Int6️⃣
-        let a4: 7️⃣String: Int]??
+        let a5: 7️⃣String: Int]??
       }
       """,
       diagnostics: [
@@ -1577,10 +1589,22 @@ final class RecoveryTests: XCTestCase {
           let a2: [String: Int]
           let a3: [String: [Int]]
           let a4: [String: Int]
-          let a4: [String: Int]??
+          let a5: [String: Int]??
         }
         """
     )
+
+    assertParse(
+      """
+      let a6: [Int: String]
+      1️⃣]
+      """,
+      diagnostics: [
+        DiagnosticSpec(
+          message: "extraneous code ']' at top level"
+        )
+      ]
+    )
   }
 
   func testRecovery100() {