From e3d86f84759e07ca644c5f77ef6a26e645de7364 Mon Sep 17 00:00:00 2001
From: Notime02 <94148329+Notime02@users.noreply.github.com>
Date: Sun, 21 Jun 2026 22:55:07 +0300
Subject: [PATCH] fix(#2): [$40 BOUNTY] [Go] Add order book cancellation depth
 tests

---
 market/orderbook/orderbook_test.go | 58 ++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 market/orderbook/orderbook_test.go

diff --git a/market/orderbook/orderbook_test.go b/market/orderbook/orderbook_test.go
new file mode 100644
index 00000000..94880af7
--- /dev/null
+++ b/market/orderbook/orderbook_test.go
@@ -0,0 +1,58 @@
+// orderbook_test.go
+
+package orderbook
+
+import (
+	"testing"
+)
+
+func TestCancelBid(t *testing.T) {
+	ob := NewOrderBook()
+	orderID := ob.AddBid(100, 1)
+	ob.CancelOrder(orderID)
+
+	if _, exists := ob.bids[orderID]; exists {
+		t.Fatalf("expected bid to be removed, but it still exists")
+	}
+}
+
+func TestCancelAsk(t *testing.T) {
+	ob := NewOrderBook()
+	orderID := ob.AddAsk(100, 1)
+	ob.CancelOrder(orderID)
+
+	if _, exists := ob.asks[orderID]; exists {
+		t.Fatalf("expected ask to be removed, but it still exists")
+	}
+}
+
+func TestCancelUnknownOrder(t *testing.T) {
+	ob := NewOrderBook()
+	err := ob.CancelOrder("unknownID")
+
+	if err != ErrOrderNotFound {
+		t.Fatalf("expected ErrOrderNotFound, got %v", err)
+	}
+}
+
+func TestClosedBookRejectsOperations(t *testing.T) {
+	ob := NewOrderBook()
+	ob.Close()
+	err := ob.AddBid(100, 1)
+
+	if err != ErrBookClosed {
+		t.Fatalf("expected ErrBookClosed, got %v", err)
+	}
+}
+
+func TestSnapshotImmutability(t *testing.T) {
+	ob := NewOrderBook()
+	ob.AddBid(100, 1)
+	snapshot := ob.Snapshot()
+
+	snapshot.Bids[0].Price = 200 // Attempt to mutate snapshot
+
+	if ob.bids[1].Price == 200 {
+		t.Fatalf("expected internal bids to be immutable")
+	}
+}