correctly set mouse events buttons property

lib/ferrum/mouse.rb

@@ -3,11 +3,19 @@
 module Ferrum
   class Mouse
     CLICK_WAIT = ENV.fetch("FERRUM_CLICK_WAIT", 0.1).to_f
-    VALID_BUTTONS = %w[none left middle right back forward].freeze
+    BUTTON_MASKS = {
+      "none" => 0,
+      "left" => 1,
+      "right" => 2,
+      "middle" => 4,
+      "back" => 8,
+      "forward" => 16
+    }.freeze
 
     def initialize(page)
       @page = page
       @x = @y = 0
+      @buttons = 0
     end
 
     #
@@ -130,7 +138,8 @@ def move(x:, y:, steps: 1)
                       slowmoable: true,
                       type: "mouseMoved",
                       x: new_x.to_i,
-                      y: new_y.to_i)
+                      y: new_y.to_i,
+                      buttons: @buttons)
       end
 
       self
@@ -140,16 +149,26 @@ def move(x:, y:, steps: 1)
 
     def mouse_event(type:, button: :left, count: 1, modifiers: nil, wait: 0)
       button = validate_button(button)
-      options = { x: @x, y: @y, type: type, button: button, clickCount: count }
+      register_event_button(type, button)
+      options = { x: @x, y: @y, type: type, button: button, buttons: @buttons, clickCount: count }
       options.merge!(modifiers: modifiers) if modifiers
       @page.command("Input.dispatchMouseEvent", wait: wait, slowmoable: true, **options)
     end
 
     def validate_button(button)
       button = button.to_s
-      raise "Invalid button: #{button}" unless VALID_BUTTONS.include?(button)
+      raise "Invalid button: #{button}" unless BUTTON_MASKS.key?(button)
 
       button
     end
+
+    def register_event_button(type, button)
+      case type
+      when "mousePressed"
+        @buttons |= BUTTON_MASKS[button]
+      when "mouseReleased"
+        @buttons &= ~BUTTON_MASKS[button]
+      end
+    end
   end
 end

spec/mouse_spec.rb

@@ -44,20 +44,16 @@
   end
 
   describe "#move" do
-    let(:tracking_code) do
-      <<~JS
+    it "splits into steps" do
+      browser.go_to("/ferrum/simple")
+      browser.mouse.move(x: 100, y: 100)
+      browser.evaluate_async(<<~JS, browser.timeout)
         window.result = [];
         document.addEventListener("mousemove", e => {
           window.result.push([e.clientX, e.clientY]);
         });
         arguments[0]();
       JS
-    end
-
-    it "splits into steps" do
-      browser.go_to("/ferrum/simple")
-      browser.mouse.move(x: 100, y: 100)
-      browser.evaluate_async(tracking_code, browser.timeout)
 
       browser.mouse.move(x: 200, y: 300, steps: 5)
 
@@ -69,6 +65,43 @@
         [200, 300]
       ])
     end
+
+    it "sets buttons property" do
+      browser.go_to("/ferrum/simple")
+      browser.mouse.move(x: 100, y: 100)
+      browser.evaluate_async(<<~JS, browser.timeout)
+        window.result = [];
+        ["move", "up", "down"].forEach(type =>
+          document.addEventListener(`mouse${type}`, e => {
+            window.result.push([type, e.clientX, e.clientY, e.buttons]);
+          })
+        );
+        arguments[0]();
+      JS
+
+      browser.mouse
+             .move(x: 101, y: 102)
+             .down(button: :left)
+             .move(x: 103, y: 104)
+             .down(button: :right)
+             .move(x: 105, y: 106)
+             .up(button: :left)
+             .move(x: 107, y: 108)
+             .up(button: :right)
+             .move(x: 109, y: 110)
+
+      expect(browser.evaluate("window.result")).to eq([
+        ["move", 101, 102, 0], # none pressed
+        ["down", 101, 102, 1], # left down
+        ["move", 103, 104, 1], # left pressed
+        ["down", 103, 104, 3], # right down, left pressed
+        ["move", 105, 106, 3], # both pressed
+        ["up",   105, 106, 2], # left up, right pressed
+        ["move", 107, 108, 2], # right pressed
+        ["up",   107, 108, 0], # right up
+        ["move", 109, 110, 0] # none pressed
+      ])
+    end
   end
 
   context "mouse support", skip: true do