fix: browser.reset tries to dispose default implicit context #540 (#566)

Old Chrome doesn't even show implicit context.
`Target.getBrowserContexts` returns `{"browserContextIds":[]}`
`Target.setAutoAttach` doesn't send any `Target.attachedToTarget` events nor does `Target.setDiscoverTargets`. This context is not even registered in Ferrum.

More recent Chrome < 145 still returns empty {"browserContextIds":[]} but starts to show target and context in `Target.attachedToTarget` and `Target.targetCreated`.

Chrome >= 145 returns defaultBrowserContextId `{"browserContextIds":[],"defaultBrowserContextId":"7354CC1034D553EE803954E18CDEB447"}` and shows target and context as above.

--no-startup-window flag tells Chrome not to open any browser window on startup thus affecting implicit context in a more recent Chrome. When flag is passed we create our own default context, and thus can dispose it. When flag is not passed we use implicit context and thus cannot dispose it.

Author: route

lib/ferrum/contexts.rb

@@ -48,6 +48,8 @@ def create(**options)
 
     def dispose(context_id)
       context = @contexts[context_id]
+      return unless context
+
       context.close_targets_connection
       @client.command("Target.disposeBrowserContext", browserContextId: context.id)
       @contexts.delete(context_id)
@@ -59,8 +61,9 @@ def close_connections
     end
 
     def reset
-      @default_context = nil
-      @contexts.each_key { |id| dispose(id) }
+      context_ids = @client.command("Target.getBrowserContexts")["browserContextIds"]
+      @default_context = nil if context_ids.include?(@default_context&.id)
+      @contexts.each_key { |id| dispose(id) if context_ids.include?(id) }
     end
 
     def size
@@ -69,18 +72,13 @@ def size
 
     private
 
-    # rubocop:disable Metrics/PerceivedComplexity, Metrics/CyclomaticComplexity
-    def subscribe
+    def subscribe # rubocop:disable Metrics/PerceivedComplexity
       @client.on("Target.attachedToTarget") do |params|
         info, session_id = params.values_at("targetInfo", "sessionId")
         next unless ALLOWED_TARGET_TYPES.include?(info["type"])
 
         context_id = info["browserContextId"]
-        unless @contexts[context_id]
-          context = Context.new(@client, self, context_id)
-          @contexts[context_id] = context
-          @default_context ||= context
-        end
+        add_context(context_id)
 
         @contexts[context_id]&.add_target(session_id: session_id, params: info)
         if params["waitingForDebugger"]
@@ -93,6 +91,7 @@ def subscribe
         next unless ALLOWED_TARGET_TYPES.include?(info["type"])
 
         context_id = info["browserContextId"]
+        add_context(context_id)
 
         if info["type"] == "iframe" &&
            (target = @contexts[context_id].find_target { |t| t.connected? && t.page.frame_by(id: info["targetId"]) })
@@ -120,16 +119,21 @@ def subscribe
         context&.delete_target(params["targetId"])
       end
     end
-    # rubocop:enable Metrics/PerceivedComplexity, Metrics/CyclomaticComplexity
 
     def discover
       @client.command("Target.setDiscoverTargets", discover: true)
     end
 
     def auto_attach
-      return unless @client.options.flatten
-
       @client.command("Target.setAutoAttach", autoAttach: true, waitForDebuggerOnStart: true, flatten: true)
     end
+
+    def add_context(context_id)
+      return if @contexts[context_id]
+
+      context = Context.new(@client, self, context_id)
+      @contexts[context_id] = context
+      @default_context ||= context # rubocop:disable Naming/MemoizedInstanceVariableName
+    end
   end
 end