Use accept_alert to get the alert message.

  • Poltergeist ignores alerts/confirms by default(source)
  • Poltergeist has had support for Capybaras modal api since September 2015( source)

That means you can same syntax for Poltergeist or capybara-webkit.

expect(accept_alert).to eq("Javascript alert message")

# or with block syntax

# will fail if alert message doesn't match
accept_alert("Javascript alert message") do 
  # next expectation

The first one expect(accept_alert).to reads a bit weird, but that's the return value of accept_alert.

October 29, 2013 #capybara

I got a brand new Mac Air recently, when I tried to install
capybara-webkit I encountered some problems.

The Error

Got this error when bundle install one rails app.

Installing capybara-webkit (0.12.1)
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

    /Users/qihuan-piao/.rvm/rubies/ruby-2.0.0-p247/bin/ruby extconf.rb

Gem files will remain installed in /Users/qihuan-piao/.rvm/gems/ruby-2.0.0-p247/gems/capybara-webkit-0.12.1 for inspection.
Results logged to /Users/qihuan-piao/.rvm/gems/ruby-2.0.0-p247/gems/capybara-webkit-0.12.1/./gem_make.out

An error occurred while installing capybara-webkit (0.12.1), and Bundler cannot continue.
Make sure that `gem install capybara-webkit -v '0.12.1'` succeeds before bundling.

Tried brew install qt didn’t get luck, raised this error:

brew install qt4 --build-from-source
==> Downloading
Already downloaded: /Library/Caches/Homebrew/qt-4.8.5.tar.gz
==> ./configure -prefix /usr/local/Cellar/qt/4.8.5 -system-zlib -confirm-license -opensource -nomake demos -nomake examples -cocoa -fast -release -no-3dnow -L/opt/X11/lib -I/opt/X11/include -pl
==> make
7 errors generated.
make[2]: *** [.obj/release-shared/qdrawhelper_ssse3.o] Error 1
make[1]: *** [release] Error 2
make: *** [sub-gui-make_default-ordered] Error 2


These open issues may also help:


Checked all those links and tried several things, eventually downloading
qt installer from the qt-project website solved my problem.

Download link

Just install the debug libraries, qt libraries then bundle install


If you already got qt installed and capybara-webkit worked before
upgrade to Mavericks, then it’s probably gonna work as well.