Decrease max nesting level in debug

Author: kimdv

Sources/SwiftParser/Parser.swift

@@ -119,7 +119,7 @@ public struct Parser {
   /// explicitly specify one. Debug builds of the parser consume a lot more stack
   /// space and thus have a lower default maximum nesting level.
   #if DEBUG
-  static let defaultMaximumNestingLevel = 25
+  static let defaultMaximumNestingLevel = 20
   #else
   static let defaultMaximumNestingLevel = 256
   #endif

Tests/SwiftParserTest/ParserTests.swift

@@ -23,8 +23,8 @@ public class ParserTests: XCTestCase {
     let fileContents = try Data(contentsOf: fileURL)
     let parsed = fileContents.withUnsafeBytes({ buffer in
       // Release builds are fine with the default maximum nesting level of 256.
-      // Debug builds overflow with any stack size bigger than 25-ish.
-      Parser.parse(source: buffer.bindMemory(to: UInt8.self), maximumNestingLevel: 25)
+      // Debug builds overflow with any stack size bigger than 20-ish.
+      Parser.parse(source: buffer.bindMemory(to: UInt8.self), maximumNestingLevel: 20)
     })
     assertDataEqualWithDiff(
       Data(parsed.syntaxTextBytes),