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Testing Screenshot Generation Workflow in teamcapybara/capybara

This test suite validates Capybara’s screenshot functionality, focusing on the save_screenshot feature. It verifies proper file naming, path handling, and integration with Capybara’s save path configuration.

Test Coverage Overview

The test suite comprehensively covers screenshot saving functionality in Capybara:

Default filename generation and path handling
Custom path specification capabilities
Integration with Capybara.save_path configuration
Relative and absolute path handling

Implementation Analysis

The testing approach utilizes RSpec’s context-based structure with mock expectations. It employs driver interaction mocking to verify correct path construction and file saving behavior without actually writing files.

Uses RSpec’s allow/receive pattern for driver interaction
Implements before/after hooks for test isolation
Leverages regex matching for dynamic filename verification

Technical Details

Key technical components include:

RSpec test framework
Capybara::SpecHelper for test setup
FileUtils for cleanup operations
Dynamic path construction using File.join
Regular expressions for filename validation

Best Practices Demonstrated

The test suite exemplifies several testing best practices:

Proper test isolation through before/after hooks
Clean environment management
Comprehensive edge case coverage
Effective use of mocking to test file operations
Clear test organization using RSpec contexts

teamcapybara/capybara

lib/capybara/spec/session/save_screenshot_spec.rb

            
# frozen_string_literal: true

Capybara::SpecHelper.spec '#save_screenshot', requires: [:screenshot] do
  let(:alternative_path) { File.join(Dir.pwd, 'save_screenshot_tmp') }
  before do
    @old_save_path = Capybara.save_path
    Capybara.save_path = nil
    @session.visit '/foo'
  end

  after do
    Capybara.save_path = @old_save_path
    FileUtils.rm_rf alternative_path
  end

  it 'generates sensible filename' do
    allow(@session.driver).to receive(:save_screenshot)

    @session.save_screenshot

    regexp = Regexp.new(File.join(Dir.pwd, 'capybara-\d+\.png'))
    expect(@session.driver).to have_received(:save_screenshot).with(regexp, any_args)
  end

  it 'allows to specify another path' do
    allow(@session.driver).to receive(:save_screenshot)

    custom_path = 'screenshots/1.png'
    @session.save_screenshot(custom_path)

    expect(@session.driver).to have_received(:save_screenshot).with(/#{custom_path}$/, any_args)
  end

  context 'with Capybara.save_path' do
    it 'file is generated in the correct location' do
      Capybara.save_path = alternative_path
      allow(@session.driver).to receive(:save_screenshot)

      @session.save_screenshot

      regexp = Regexp.new(File.join(alternative_path, 'capybara-\d+\.png'))
      expect(@session.driver).to have_received(:save_screenshot).with(regexp, any_args)
    end

    it 'relative paths are relative to save_path' do
      Capybara.save_path = alternative_path
      allow(@session.driver).to receive(:save_screenshot)

      custom_path = 'screenshots/2.png'
      @session.save_screenshot(custom_path)

      expect(@session.driver).to have_received(:save_screenshot).with(File.expand_path(custom_path, alternative_path), any_args)
    end
  end
end