add test

spec/http_auth_spec.cr

@@ -0,0 +1,15 @@
+require "./spec_helper"
+
+WebMock.stub(:get, "http://auth.example.com/")
+  .with(headers: {"Authorization" => "Basic #{Base64.strict_encode("user:pass").chomp}"})
+  .to_return(status: 200)
+
+WebMock.stub(:get, "http://auth.example.com/")
+  .to_return(status: 401, headers: {"WWW-Authenticate" => "Basic realm=\"Access to the staging site\", charset=\"UTF-8\""})
+
+describe "Mechanize HTTP Authentication test" do
+  it "auth" do
+    agent = Mechanize.new
+    agent.get("http://auth.example.com/")
+  end
+end

src/mechanize/http/agent.cr

@@ -47,6 +47,10 @@ class Mechanize
           return follow_redirect(response, headers, page)
         end
 
+        if response && response.status.unauthorized?
+          response_authenticate(response)
+        end
+
         page
       end
 
@@ -220,6 +224,10 @@ class Mechanize
         target_url
       end
 
+      private def response_authenticate(response)
+        www_authenticate = response.headers["www-authenticate"]
+      end
+
       # reset request cookie before setting headers.
       private def reset_request_header_cookies
         request_headers.delete("Cookie")