Increase branch test coverage

lib/rex/matcher.rb

@@ -6,7 +6,7 @@ module Rex
       lowest_sell_order = order_book.lowest_sell_order
       return trades if highest_buy_order.nil? || lowest_sell_order.nil?
 
-      while highest_buy_order&.price&.>= lowest_sell_order&.price
+      while highest_buy_order.price >= lowest_sell_order.price
         max_amount = [highest_buy_order.remaining_amount, lowest_sell_order.remaining_amount].min
         highest_buy_order.remaining_amount -= max_amount
         lowest_sell_order.remaining_amount -= max_amount

spec/order_book_spec.rb

@@ -85,6 +85,14 @@ RSpec.describe Rex::OrderBook do
     end
   end
 
+  describe "#best_sell_price" do
+    context "when the order book is empty" do
+      it "returns nil" do
+        expect(instance.best_sell_price).to eq(nil)
+      end
+    end
+  end
+
   describe "#lowest_sell_Order" do
     context "when there is nothing in the book" do
       it "returns nil " do
@@ -101,6 +109,12 @@ RSpec.describe Rex::OrderBook do
       instance.add_order(buy_order)
     end
 
+    context "when the order id is unknown" do
+      it "returns nil" do
+        expect(instance.cancel_order(-1)).to eq(nil)
+      end
+    end
+
     context "when it is the last order for the given price" do
       it "removes the order from the side" do
         instance.cancel_order(buy_order.id)
@@ -109,6 +123,20 @@ RSpec.describe Rex::OrderBook do
       end
     end
 
+    context "when it is not the last order for the given price" do
+      let(:another_buy_order) { build(:order, is_buy: true, price: 100) }
+
+      before do
+        instance.add_order(another_buy_order)
+      end
+
+      it "removes the order from the side" do
+        instance.cancel_order(buy_order.id)
+
+        expect(instance.best_buy_price).to eq(100)
+      end
+    end
+
     context "an order on the sell side is removed" do
       before do
         instance.add_order(buy_order)

spec/spec_helper.rb

@@ -2,7 +2,9 @@
 
 require "simplecov"
 
-SimpleCov.start
+SimpleCov.start do
+  enable_coverage :branch
+end
 require "rex"
 
 Dir[