feat: Implement Ferrum::Page#activate

CHANGELOG.md

@@ -8,7 +8,8 @@
 - `Ferrum::Node#exists?` check whether the node in ruby world still exists in the DOM tree.
 - `Ferrum::Cookies#store` stores all cookies of current page in a file.
 - `Ferrum::Cookies#load` Loads all cookies from the file and sets them for current page.
-- `Ferrum::Page#screenshot` supports webp image format
+- `Ferrum::Page#screenshot` supports webp image format.
+- `Ferrum::Page#activate` activates the target for the given page.
 
 ### Changed
 

lib/ferrum/page.rb

@@ -336,6 +336,19 @@ def bypass_csp(enabled: true)
       enabled
     end
 
+    #
+    # Activates (focuses) the target for the given page. When you have multiple tabs you work with, and you need to switch a given one.
+    #
+    # @return [Boolean]
+    #
+    # @example
+    #   page.activate # => true
+    #
+    def activate
+      command("Target.activateTarget", targetId: target_id)
+      true
+    end
+
     def command(method, wait: 0, slowmoable: false, **params)
       iteration = @event.reset if wait.positive?
       sleep(@options.slowmo) if slowmoable && @options.slowmo.positive?