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Testing Browser Window Management Operations in Capybara

This test suite examines window management functionality in Capybara, focusing on browser window manipulation and state verification. It validates core window operations like opening, closing, resizing, and switching between multiple browser windows in automated tests.

Test Coverage Overview

The test suite provides comprehensive coverage of window management operations in Capybara:

Window state verification (exists?, closed?, current?)
Window manipulation (close, resize, maximize, fullscreen)
Window size management and validation
Multiple window handling and switching

Implementation Analysis

The testing approach uses RSpec’s behavior-driven development patterns with Capybara’s window management API. It employs before/after hooks for setup and cleanup, and implements careful state management for window operations.

Notable patterns include window context switching, size verification, and window state tracking across operations.

Technical Details

Testing Framework: RSpec
Primary Library: Capybara
Key Components: Window API, JavaScript integration
Test Prerequisites: :windows, :js capabilities
Setup Requirements: Browser window management support

Best Practices Demonstrated

The test suite exemplifies several testing best practices:

Proper test isolation and cleanup
Careful state management between tests
Explicit handling of asynchronous operations
Comprehensive edge case coverage
Clear test organization and grouping

teamcapybara/capybara

lib/capybara/spec/session/window/window_spec.rb

            
# frozen_string_literal: true

# NOTE: This file uses `sleep` to sync up parts of the tests. This is only implemented like this
# because of the methods being tested. In tests using Capybara this type of behavior should be implemented
# using Capybara provided assertions with builtin waiting behavior.

Capybara::SpecHelper.spec Capybara::Window, requires: [:windows] do
  let!(:orig_window) { @session.current_window }
  before do
    @session.visit('/with_windows')
  end

  after do
    (@session.windows - [orig_window]).each do |w|
      @session.switch_to_window w
      w.close
    end
    @session.switch_to_window(orig_window)
  end

  describe '#exists?' do
    it 'should become false after window was closed' do
      other_window = @session.window_opened_by do
        @session.find(:css, '#openWindow').click
      end

      expect do
        @session.switch_to_window other_window
        other_window.close
      end.to change(other_window, :exists?).from(true).to(false)
    end
  end

  describe '#closed?' do
    it 'should become true after window was closed' do
      other_window = @session.window_opened_by do
        @session.find(:css, '#openWindow').click
      end
      expect do
        @session.switch_to_window other_window
        other_window.close
      end.to change { other_window.closed? }.from(false).to(true)
    end
  end

  describe '#current?' do
    let(:other_window) do
      @session.window_opened_by do
        @session.find(:css, '#openWindow').click
      end
    end

    it 'should become true after switching to window' do
      expect do
        @session.switch_to_window(other_window)
      end.to change(other_window, :current?).from(false).to(true)
    end

    it 'should return false if window is closed' do
      @session.switch_to_window(other_window)
      other_window.close
      expect(other_window.current?).to be(false)
    end
  end

  describe '#close' do
    let!(:other_window) do
      @session.window_opened_by do
        @session.find(:css, '#openWindow').click
      end
    end

    it 'should switch to original window if invoked not for current window' do
      expect(@session.windows.size).to eq(2)
      expect(@session.current_window).to eq(orig_window)
      other_window.close
      expect(@session.windows.size).to eq(1)
      expect(@session.current_window).to eq(orig_window)
    end

    it 'should make subsequent invocations of other methods raise no_such_window_error if invoked for current window' do
      @session.switch_to_window(other_window)
      expect(@session.current_window).to eq(other_window)
      other_window.close
      expect do
        @session.find(:css, '#some_id')
      end.to raise_error(@session.driver.no_such_window_error)
      @session.switch_to_window(orig_window)
    end
  end

  describe '#size' do
    def win_size
      @session.evaluate_script('[window.outerWidth || window.innerWidth, window.outerHeight || window.innerHeight]')
    end

    it 'should return size of whole window', requires: %i[windows js] do
      expect(@session.current_window.size).to eq win_size
    end

    it 'should switch to original window if invoked not for current window' do
      other_window = @session.window_opened_by do
        @session.find(:css, '#openWindow').click
      end
      sleep 1
      size = @session.within_window(other_window) do
        win_size
      end
      expect(other_window.size).to eq(size)
      expect(@session.current_window).to eq(orig_window)
    end
  end

  describe '#resize_to' do
    let!(:initial_size) { @session.current_window.size }

    after do
      @session.current_window.resize_to(*initial_size)
      sleep 1
    end

    it 'should be able to resize window', requires: %i[windows js] do
      width, height = initial_size
      @session.current_window.resize_to(width - 100, height - 100)
      sleep 1
      expect(@session.current_window.size).to eq([width - 100, height - 100])
    end

    it 'should stay on current window if invoked not for current window', requires: %i[windows js] do
      other_window = @session.window_opened_by do
        @session.find(:css, '#openWindow').click
      end

      other_window.resize_to(600, 400)
      expect(@session.current_window).to eq(orig_window)

      @session.within_window(other_window) do
        expect(@session.current_window.size).to eq([600, 400])
      end
    end
  end

  describe '#maximize' do
    let! :initial_size do
      @session.current_window.size
    end

    after do
      @session.current_window.resize_to(*initial_size)
      sleep 0.5
    end

    it 'should be able to maximize window', requires: %i[windows js] do
      start_width, start_height = 400, 300
      @session.current_window.resize_to(start_width, start_height)
      sleep 0.5

      @session.current_window.maximize
      sleep 0.5 # The timing on maximize is finicky on Travis -- wait a bit for maximize to occur

      max_width, max_height = @session.current_window.size

      # maximize behavior is window manage dependant, so just make sure it increases in size
      expect(max_width).to be > start_width
      expect(max_height).to be > start_height
    end

    it 'should stay on current window if invoked not for current window', requires: %i[windows js] do
      other_window = @session.window_opened_by do
        @session.find(:css, '#openWindow').click
      end
      other_window.resize_to(400, 300)
      sleep 0.5
      other_window.maximize
      sleep 0.5 # The timing on maximize is finicky on Travis -- wait a bit for maximize to occur

      expect(@session.current_window).to eq(orig_window)
      # Maximizing the browser affects all tabs so this may not be valid in real browsers
      # expect(@session.current_window.size).to eq(initial_size)

      ow_width, ow_height = other_window.size
      expect(ow_width).to be > 400
      expect(ow_height).to be > 300
    end
  end

  describe '#fullscreen' do
    let! :initial_size do
      @session.current_window.size
    end

    after do
      @session.current_window.resize_to(*initial_size)
      sleep 1
    end

    it 'should be able to fullscreen the window' do
      expect do
        @session.current_window.fullscreen
      end.not_to raise_error
    end
  end
end