diff --git a/benchmark/dartchess_benchmark.dart b/benchmark/dartchess_benchmark.dart
index a8849e3..9286d77 100644
--- a/benchmark/dartchess_benchmark.dart
+++ b/benchmark/dartchess_benchmark.dart
@@ -33,10 +33,14 @@ void main() {
 
   final legalMovesPos = Chess.fromSetup(Setup.parseFen(
       'rn1qkb1r/pbp2ppp/1p2p3/3n4/8/2N2NP1/PP1PPPBP/R1BQ1RK1 b kq -'));
-  benchmark('valid fen moves', () {
+  benchmark('valid moves', () {
     legalMovesPos.legalMoves.length;
   });
 
+  benchmark('makeLegalMoves (with alternate castling moves)', () {
+    makeLegalMoves(legalMovesPos);
+  });
+
   benchmark('parsePgn - kasparov-deep-blue', () {
     final String data =
         io.File('./data/kasparov-deep-blue-1997.pgn').readAsStringSync();
diff --git a/test/pgn_test.dart b/test/pgn_test.dart
index 2854450..0eb5f6a 100644
--- a/test/pgn_test.dart
+++ b/test/pgn_test.dart
@@ -195,6 +195,52 @@ void main() {
     test('PgnComment implements hashCode/==', () {
       const comment = '[%csl Ga1][%cal Ra1h1,Gb1b8] foo [%clk 3:25:45]';
       expect(PgnComment.fromPgn(comment) == PgnComment.fromPgn(comment), true);
+      expect(
+          PgnComment.fromPgn(comment).hashCode,
+          PgnComment.fromPgn(comment).hashCode);
+    });
+
+    test('PgnComment == distinguishes shapes content', () {
+      const withShape = PgnComment(shapes: [
+        PgnCommentShape(color: CommentShapeColor.green, from: Square.a1, to: Square.a1),
+      ]);
+      const withDifferentShape = PgnComment(shapes: [
+        PgnCommentShape(color: CommentShapeColor.red, from: Square.a1, to: Square.a1),
+      ]);
+      const withoutShape = PgnComment();
+
+      expect(withShape, withShape);
+      expect(withShape, isNot(withDifferentShape));
+      expect(withShape, isNot(withoutShape));
+      expect(withoutShape, withoutShape);
+    });
+
+    test('PgnComment == is order-sensitive for shapes', () {
+      const shapeA = PgnCommentShape(
+          color: CommentShapeColor.green, from: Square.a1, to: Square.h1);
+      const shapeB = PgnCommentShape(
+          color: CommentShapeColor.red, from: Square.b1, to: Square.b8);
+
+      const ab = PgnComment(shapes: [shapeA, shapeB]);
+      const ba = PgnComment(shapes: [shapeB, shapeA]);
+
+      expect(ab, isNot(ba));
+    });
+
+    test('PgnComment hashCode consistent with ==', () {
+      const shapeA = PgnCommentShape(
+          color: CommentShapeColor.green, from: Square.a1, to: Square.h1);
+      const shapeB = PgnCommentShape(
+          color: CommentShapeColor.red, from: Square.b1, to: Square.b8);
+
+      const c1 = PgnComment(text: 'hello', shapes: [shapeA, shapeB]);
+      const c2 = PgnComment(text: 'hello', shapes: [shapeA, shapeB]);
+      expect(c1, c2);
+      expect(c1.hashCode, c2.hashCode);
+
+      // Can be used as a map key.
+      final map = {c1: 42};
+      expect(map[c2], 42);
     });
 
     group('Invalid Pgns', () {
diff --git a/test/setup_test.dart b/test/setup_test.dart
index 095dd6e..5689166 100644
--- a/test/setup_test.dart
+++ b/test/setup_test.dart
@@ -124,5 +124,43 @@ void main() {
               .of(Side.white, Role.knight),
           0);
     });
+
+    test('implements ==', () {
+      expect(Pockets.empty, Pockets.empty);
+
+      final a = Pockets.empty.increment(Side.white, Role.knight);
+      final b = Pockets.empty.increment(Side.white, Role.knight);
+      expect(a, b);
+
+      final c = Pockets.empty.increment(Side.black, Role.knight);
+      expect(a, isNot(c));
+
+      final d = Pockets.empty.increment(Side.white, Role.pawn);
+      expect(a, isNot(d));
+
+      // incrementing then decrementing round-trips back to empty
+      expect(
+        Pockets.empty
+            .increment(Side.white, Role.rook)
+            .decrement(Side.white, Role.rook),
+        Pockets.empty,
+      );
+    });
+
+    test('implements hashCode', () {
+      final a = Pockets.empty.increment(Side.white, Role.knight);
+      final b = Pockets.empty.increment(Side.white, Role.knight);
+      expect(a.hashCode, b.hashCode);
+
+      expect(Pockets.empty.hashCode, Pockets.empty.hashCode);
+
+      // Different pockets should (almost certainly) have different hashes.
+      final c = Pockets.empty.increment(Side.black, Role.queen);
+      expect(a.hashCode, isNot(c.hashCode));
+
+      // Can be used as a map key.
+      final map = {a: 'knight'};
+      expect(map[b], 'knight');
+    });
   });
 }