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Testing Selector Assertions and Element Validation in Capybara

This test suite validates Capybara’s selector assertion functionality, covering both positive (assert_selector) and negative (assert_no_selector) cases. The tests verify element selection across different selector types, scoping, counting, and text matching scenarios.

Test Coverage Overview

The test suite provides comprehensive coverage of Capybara’s selector assertions functionality.

Basic selector validation using XPath and CSS
Element presence and absence verification
Scoped element testing within specific contexts
Count-based element assertions
Text content matching using strings and regular expressions
Asynchronous element testing with wait timeouts

Implementation Analysis

The implementation follows a structured approach using RSpec-style testing patterns.

Tests utilize Capybara’s session management and navigation capabilities, with specific focus on selector assertions. The suite demonstrates both synchronous and asynchronous testing scenarios, leveraging Capybara’s wait functionality for JavaScript-enabled tests.

Technical Details

Testing Framework: RSpec with Capybara
Selector Types: XPath and CSS
Session Management: Capybara::Session
Error Handling: Capybara::ElementNotFound
Configuration: Default selector settings
JavaScript Support: Async testing capabilities

Best Practices Demonstrated

The test suite exemplifies several testing best practices:

Thorough error case coverage
Consistent setup and teardown
Clear test organization and grouping
Proper isolation of test scenarios
Effective use of context blocks
Comprehensive selector testing strategies

teamcapybara/capybara

lib/capybara/spec/session/assert_selector_spec.rb

            
# frozen_string_literal: true

Capybara::SpecHelper.spec '#assert_selector' do
  before do
    @session.visit('/with_html')
  end

  it 'should be true if the given selector is on the page' do
    @session.assert_selector(:xpath, '//p')
    @session.assert_selector(:css, 'p a#foo')
    @session.assert_selector("//p[contains(.,'est')]")
  end

  it 'should be false if the given selector is not on the page' do
    expect { @session.assert_selector(:xpath, '//abbr') }.to raise_error(Capybara::ElementNotFound)
    expect { @session.assert_selector(:css, 'p a#doesnotexist') }.to raise_error(Capybara::ElementNotFound)
    expect { @session.assert_selector("//p[contains(.,'thisstringisnotonpage')]") }.to raise_error(Capybara::ElementNotFound)
  end

  it 'should use default selector' do
    Capybara.default_selector = :css
    expect { @session.assert_selector('p a#doesnotexist') }.to raise_error(Capybara::ElementNotFound)
    @session.assert_selector('p a#foo')
  end

  it 'should respect scopes' do
    @session.within "//p[@id='first']" do
      @session.assert_selector(".//a[@id='foo']")
      expect { @session.assert_selector(".//a[@id='red']") }.to raise_error(Capybara::ElementNotFound)
    end
  end

  context 'with count' do
    it 'should be true if the content is on the page the given number of times' do
      @session.assert_selector('//p', count: 3)
      @session.assert_selector("//p//a[@id='foo']", count: 1)
      @session.assert_selector("//p[contains(.,'est')]", count: 1)
    end

    it 'should be false if the content is on the page the given number of times' do
      expect { @session.assert_selector('//p', count: 6) }.to raise_error(Capybara::ElementNotFound)
      expect { @session.assert_selector("//p//a[@id='foo']", count: 2) }.to raise_error(Capybara::ElementNotFound)
      expect { @session.assert_selector("//p[contains(.,'est')]", count: 5) }.to raise_error(Capybara::ElementNotFound)
    end

    it "should be false if the content isn't on the page at all" do
      expect { @session.assert_selector('//abbr', count: 2) }.to raise_error(Capybara::ElementNotFound)
      expect { @session.assert_selector("//p//a[@id='doesnotexist']", count: 1) }.to raise_error(Capybara::ElementNotFound)
    end
  end

  context 'with text' do
    it 'should discard all matches where the given string is not contained' do
      @session.assert_selector('//p//a', text: 'Redirect', count: 1)
      expect { @session.assert_selector('//p', text: 'Doesnotexist') }.to raise_error(Capybara::ElementNotFound)
    end

    it 'should discard all matches where the given regexp is not matched' do
      @session.assert_selector('//p//a', text: /re[dab]i/i, count: 1)
      expect { @session.assert_selector('//p//a', text: /Red$/) }.to raise_error(Capybara::ElementNotFound)
    end
  end

  context 'with wait', requires: [:js] do
    it 'should find element if it appears before given wait duration' do
      Capybara.using_wait_time(0.1) do
        @session.visit('/with_js')
        @session.click_link('Click me')
        @session.assert_selector(:css, 'a#has-been-clicked', text: 'Has been clicked', wait: 2)
      end
    end
  end
end

Capybara::SpecHelper.spec '#assert_no_selector' do
  before do
    @session.visit('/with_html')
  end

  it 'should be false if the given selector is on the page' do
    expect { @session.assert_no_selector(:xpath, '//p') }.to raise_error(Capybara::ElementNotFound)
    expect { @session.assert_no_selector(:css, 'p a#foo') }.to raise_error(Capybara::ElementNotFound)
    expect { @session.assert_no_selector("//p[contains(.,'est')]") }.to raise_error(Capybara::ElementNotFound)
  end

  it 'should be true if the given selector is not on the page' do
    @session.assert_no_selector(:xpath, '//abbr')
    @session.assert_no_selector(:css, 'p a#doesnotexist')
    @session.assert_no_selector("//p[contains(.,'thisstringisnotonpage')]")
  end

  it 'should use default selector' do
    Capybara.default_selector = :css
    @session.assert_no_selector('p a#doesnotexist')
    expect { @session.assert_no_selector('p a#foo') }.to raise_error(Capybara::ElementNotFound)
  end

  it 'should respect scopes' do
    @session.within "//p[@id='first']" do
      expect { @session.assert_no_selector(".//a[@id='foo']") }.to raise_error(Capybara::ElementNotFound)
      @session.assert_no_selector(".//a[@id='red']")
    end
  end

  context 'with count' do
    it 'should be false if the content is on the page the given number of times' do
      expect { @session.assert_no_selector('//p', count: 3) }.to raise_error(Capybara::ElementNotFound)
      expect { @session.assert_no_selector("//p//a[@id='foo']", count: 1) }.to raise_error(Capybara::ElementNotFound)
      expect { @session.assert_no_selector("//p[contains(.,'est')]", count: 1) }.to raise_error(Capybara::ElementNotFound)
    end

    it 'should be true if the content is on the page the wrong number of times' do
      @session.assert_no_selector('//p', count: 6)
      @session.assert_no_selector("//p//a[@id='foo']", count: 2)
      @session.assert_no_selector("//p[contains(.,'est')]", count: 5)
    end

    it "should be true if the content isn't on the page at all" do
      @session.assert_no_selector('//abbr', count: 2)
      @session.assert_no_selector("//p//a[@id='doesnotexist']", count: 1)
    end
  end

  context 'with text' do
    it 'should discard all matches where the given string is contained' do
      expect { @session.assert_no_selector('//p//a', text: 'Redirect', count: 1) }.to raise_error(Capybara::ElementNotFound)
      @session.assert_no_selector('//p', text: 'Doesnotexist')
    end

    it 'should discard all matches where the given regexp is matched' do
      expect { @session.assert_no_selector('//p//a', text: /re[dab]i/i, count: 1) }.to raise_error(Capybara::ElementNotFound)
      @session.assert_no_selector('//p//a', text: /Red$/)
    end
  end

  context 'with wait', requires: [:js] do
    it 'should not find element if it appears after given wait duration' do
      @session.visit('/with_js')
      @session.click_link('Click me')
      @session.assert_no_selector(:css, 'a#has-been-clicked', text: 'Has been clicked', wait: 0.1)
    end
  end
end