class JavascriptStatesTest

class JavascriptStatesTest extends WebDriverTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'form_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Add text formats.
        $filtered_html_format = FilterFormat::create([
            'format' => 'filtered_html',
            'name' => 'Filtered HTML',
            'weight' => 0,
            'filters' => [],
        ]);
        $filtered_html_format->save();
        $full_html_format = FilterFormat::create([
            'format' => 'full_html',
            'name' => 'Full HTML',
            'weight' => 1,
            'filters' => [],
        ]);
        $full_html_format->save();
        $normal_user = $this->drupalCreateUser([
            'use text format filtered_html',
            'use text format full_html',
        ]);
        $this->drupalLogin($normal_user);
    }
    
    /**
     * Tests the JavaScript #states functionality of form elements.
     *
     * To avoid the large cost of a dataProvider in FunctionalJavascript tests,
     * this is a single public test method that invokes a series of protected
     * methods to do assertions on specific kinds of triggering elements.
     */
    public function testJavascriptStates() {
        $this->doCheckboxTriggerTests();
        $this->doCheckboxesTriggerTests();
        $this->doTextfieldTriggerTests();
        $this->doRadiosTriggerTests();
        $this->doSelectTriggerTests();
        $this->doMultipleTriggerTests();
        $this->doNestedTriggerTests();
    }
    
    /**
     * Tests states of elements triggered by a checkbox element.
     */
    protected function doCheckboxTriggerTests() {
        $this->drupalGet('form-test/javascript-states-form');
        $page = $this->getSession()
            ->getPage();
        // Find trigger and target elements.
        $trigger = $page->findField('checkbox_trigger');
        $this->assertNotEmpty($trigger);
        $textfield_invisible_element = $page->findField('textfield_invisible_when_checkbox_trigger_checked');
        $this->assertNotEmpty($textfield_invisible_element);
        $textfield_required_element = $page->findField('textfield_required_when_checkbox_trigger_checked');
        $this->assertNotEmpty($textfield_required_element);
        $details = $this->assertSession()
            ->elementExists('css', '#edit-details-expanded-when-checkbox-trigger-checked');
        $textfield_in_details = $details->findField('textfield_in_details');
        $this->assertNotEmpty($textfield_in_details);
        $checkbox_checked_element = $page->findField('checkbox_checked_when_checkbox_trigger_checked');
        $this->assertNotEmpty($checkbox_checked_element);
        $checkbox_unchecked_element = $page->findField('checkbox_unchecked_when_checkbox_trigger_checked');
        $this->assertNotEmpty($checkbox_unchecked_element);
        $checkbox_visible_element = $page->findField('checkbox_visible_when_checkbox_trigger_checked');
        $this->assertNotEmpty($checkbox_visible_element);
        $text_format_invisible_value = $page->findField('text_format_invisible_when_checkbox_trigger_checked[value]');
        $this->assertNotEmpty($text_format_invisible_value);
        $text_format_invisible_format = $page->findField('text_format_invisible_when_checkbox_trigger_checked[format]');
        $this->assertNotEmpty($text_format_invisible_format);
        $checkboxes_all_checked_element_value1 = $page->findField('checkboxes_all_checked_when_checkbox_trigger_checked[value1]');
        $this->assertNotEmpty($checkboxes_all_checked_element_value1);
        $checkboxes_all_checked_element_value2 = $page->findField('checkboxes_all_checked_when_checkbox_trigger_checked[value2]');
        $this->assertNotEmpty($checkboxes_all_checked_element_value2);
        $checkboxes_all_checked_element_value3 = $page->findField('checkboxes_all_checked_when_checkbox_trigger_checked[value3]');
        $this->assertNotEmpty($checkboxes_all_checked_element_value3);
        $checkboxes_some_checked_element_value1 = $page->findField('checkboxes_some_checked_when_checkbox_trigger_checked[value1]');
        $this->assertNotEmpty($checkboxes_some_checked_element_value1);
        $checkboxes_some_checked_element_value2 = $page->findField('checkboxes_some_checked_when_checkbox_trigger_checked[value2]');
        $this->assertNotEmpty($checkboxes_some_checked_element_value2);
        $checkboxes_some_checked_element_value3 = $page->findField('checkboxes_some_checked_when_checkbox_trigger_checked[value3]');
        $this->assertNotEmpty($checkboxes_some_checked_element_value3);
        $checkboxes_all_disabled_element_value1 = $page->findField('checkboxes_all_disabled_when_checkbox_trigger_checked[value1]');
        $this->assertNotEmpty($checkboxes_all_disabled_element_value1);
        $checkboxes_all_disabled_element_value2 = $page->findField('checkboxes_all_disabled_when_checkbox_trigger_checked[value2]');
        $this->assertNotEmpty($checkboxes_all_disabled_element_value2);
        $checkboxes_all_disabled_element_value3 = $page->findField('checkboxes_all_disabled_when_checkbox_trigger_checked[value3]');
        $this->assertNotEmpty($checkboxes_all_disabled_element_value3);
        $checkboxes_some_disabled_element_value1 = $page->findField('checkboxes_some_disabled_when_checkbox_trigger_checked[value1]');
        $this->assertNotEmpty($checkboxes_some_disabled_element_value1);
        $checkboxes_some_disabled_element_value2 = $page->findField('checkboxes_some_disabled_when_checkbox_trigger_checked[value2]');
        $this->assertNotEmpty($checkboxes_some_disabled_element_value2);
        $checkboxes_some_disabled_element_value3 = $page->findField('checkboxes_some_disabled_when_checkbox_trigger_checked[value3]');
        $radios_checked_element = $page->findField('radios_checked_when_checkbox_trigger_checked');
        $this->assertNotEmpty($radios_checked_element);
        // We want to select the specific radio buttons, not the whole radios field itself.
        $radios_all_disabled_value1 = $this->xpath('//input[@name=:name][@value=:value]', [
            ':name' => 'radios_all_disabled_when_checkbox_trigger_checked',
            ':value' => 'value1',
        ]);
        $this->assertCount(1, $radios_all_disabled_value1);
        // We want to access the radio button directly for the rest of the test, so
        // take it out of the array we got back from xpath().
        $radios_all_disabled_value1 = reset($radios_all_disabled_value1);
        $radios_all_disabled_value2 = $this->xpath('//input[@name=:name][@value=:value]', [
            ':name' => 'radios_all_disabled_when_checkbox_trigger_checked',
            ':value' => 'value2',
        ]);
        $this->assertCount(1, $radios_all_disabled_value2);
        $radios_all_disabled_value2 = reset($radios_all_disabled_value2);
        $radios_some_disabled_value1 = $this->xpath('//input[@name=:name][@value=:value]', [
            ':name' => 'radios_some_disabled_when_checkbox_trigger_checked',
            ':value' => 'value1',
        ]);
        $this->assertCount(1, $radios_some_disabled_value1);
        $radios_some_disabled_value1 = reset($radios_some_disabled_value1);
        $radios_some_disabled_value2 = $this->xpath('//input[@name=:name][@value=:value]', [
            ':name' => 'radios_some_disabled_when_checkbox_trigger_checked',
            ':value' => 'value2',
        ]);
        $this->assertCount(1, $radios_some_disabled_value2);
        $radios_some_disabled_value2 = reset($radios_some_disabled_value2);
        // Verify initial state.
        $this->assertTrue($textfield_invisible_element->isVisible());
        $this->assertFalse($details->hasAttribute('open'));
        $this->assertFalse($textfield_in_details->isVisible());
        $this->assertFalse($textfield_required_element->hasAttribute('required'));
        $this->assertFalse($checkbox_checked_element->isChecked());
        $this->assertTrue($checkbox_unchecked_element->isChecked());
        $this->assertFalse($checkbox_visible_element->isVisible());
        $this->assertTrue($text_format_invisible_value->isVisible());
        $this->assertTrue($text_format_invisible_format->isVisible());
        $this->assertFalse($checkboxes_all_checked_element_value1->isChecked());
        $this->assertFalse($checkboxes_all_checked_element_value2->isChecked());
        $this->assertFalse($checkboxes_all_checked_element_value3->isChecked());
        $this->assertFalse($checkboxes_some_checked_element_value1->isChecked());
        $this->assertFalse($checkboxes_some_checked_element_value2->isChecked());
        $this->assertFalse($checkboxes_some_checked_element_value3->isChecked());
        $this->assertFalse($checkboxes_all_disabled_element_value1->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_all_disabled_element_value2->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_all_disabled_element_value3->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_some_disabled_element_value1->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_some_disabled_element_value2->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_some_disabled_element_value3->hasAttribute('disabled'));
        $this->assertFalse($radios_checked_element->isChecked());
        $this->assertEquals(NULL, $radios_checked_element->getValue());
        $this->assertFalse($radios_all_disabled_value1->hasAttribute('disabled'));
        $this->assertFalse($radios_all_disabled_value2->hasAttribute('disabled'));
        $this->assertFalse($radios_some_disabled_value1->hasAttribute('disabled'));
        $this->assertFalse($radios_some_disabled_value2->hasAttribute('disabled'));
        // Change state: check the checkbox.
        $trigger->check();
        // Verify triggered state.
        $this->assertFalse($textfield_invisible_element->isVisible());
        $this->assertEquals('required', $textfield_required_element->getAttribute('required'));
        $this->assertTrue($details->hasAttribute('open'));
        $this->assertTrue($textfield_in_details->isVisible());
        $this->assertTrue($checkbox_checked_element->isChecked());
        $this->assertFalse($checkbox_unchecked_element->isChecked());
        $this->assertTrue($checkbox_visible_element->isVisible());
        $this->assertFalse($text_format_invisible_value->isVisible());
        $this->assertFalse($text_format_invisible_format->isVisible());
        // All 3 of the other set should be checked.
        $this->assertTrue($checkboxes_all_checked_element_value1->isChecked());
        $this->assertTrue($checkboxes_all_checked_element_value2->isChecked());
        $this->assertTrue($checkboxes_all_checked_element_value3->isChecked());
        // Value 1 and 3 should now be checked.
        $this->assertTrue($checkboxes_some_checked_element_value1->isChecked());
        $this->assertTrue($checkboxes_some_checked_element_value3->isChecked());
        // Only value 2 should remain unchecked.
        $this->assertFalse($checkboxes_some_checked_element_value2->isChecked());
        // All 3 of these should be disabled.
        $this->assertTrue($checkboxes_all_disabled_element_value1->hasAttribute('disabled'));
        $this->assertTrue($checkboxes_all_disabled_element_value2->hasAttribute('disabled'));
        $this->assertTrue($checkboxes_all_disabled_element_value3->hasAttribute('disabled'));
        // Only values 1 and 3 should be disabled, 2 should still be enabled.
        $this->assertTrue($checkboxes_some_disabled_element_value1->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_some_disabled_element_value2->hasAttribute('disabled'));
        $this->assertTrue($checkboxes_some_disabled_element_value3->hasAttribute('disabled'));
        $this->assertEquals('value1', $radios_checked_element->getValue());
        // Both of these should now be disabled.
        $this->assertTrue($radios_all_disabled_value1->hasAttribute('disabled'));
        $this->assertTrue($radios_all_disabled_value2->hasAttribute('disabled'));
        // Only value1 should be disabled, value 2 should remain enabled.
        $this->assertTrue($radios_some_disabled_value1->hasAttribute('disabled'));
        $this->assertFalse($radios_some_disabled_value2->hasAttribute('disabled'));
        // Change state: uncheck the checkbox.
        $trigger->uncheck();
        // Verify triggered state, which should match the initial state.
        $this->assertTrue($textfield_invisible_element->isVisible());
        $this->assertFalse($details->hasAttribute('open'));
        $this->assertFalse($textfield_in_details->isVisible());
        $this->assertFalse($textfield_required_element->hasAttribute('required'));
        $this->assertFalse($checkbox_checked_element->isChecked());
        $this->assertTrue($checkbox_unchecked_element->isChecked());
        $this->assertFalse($checkbox_visible_element->isVisible());
        $this->assertTrue($text_format_invisible_value->isVisible());
        $this->assertTrue($text_format_invisible_format->isVisible());
        $this->assertFalse($checkboxes_all_checked_element_value1->isChecked());
        $this->assertFalse($checkboxes_all_checked_element_value2->isChecked());
        $this->assertFalse($checkboxes_all_checked_element_value3->isChecked());
        $this->assertFalse($checkboxes_some_checked_element_value1->isChecked());
        $this->assertFalse($checkboxes_some_checked_element_value2->isChecked());
        $this->assertFalse($checkboxes_some_checked_element_value3->isChecked());
        $this->assertFalse($checkboxes_all_disabled_element_value1->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_all_disabled_element_value2->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_all_disabled_element_value3->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_some_disabled_element_value1->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_some_disabled_element_value2->hasAttribute('disabled'));
        $this->assertFalse($checkboxes_some_disabled_element_value3->hasAttribute('disabled'));
        $this->assertFalse($radios_checked_element->isChecked());
        $this->assertEquals(NULL, $radios_checked_element->getValue());
        $this->assertFalse($radios_all_disabled_value1->hasAttribute('disabled'));
        $this->assertFalse($radios_all_disabled_value2->hasAttribute('disabled'));
        $this->assertFalse($radios_some_disabled_value1->hasAttribute('disabled'));
        $this->assertFalse($radios_some_disabled_value2->hasAttribute('disabled'));
    }
    
    /**
     * Tests states of elements triggered by a checkboxes element.
     */
    protected function doCheckboxesTriggerTests() {
        $this->drupalGet('form-test/javascript-states-form');
        $page = $this->getSession()
            ->getPage();
        // Find trigger and target elements.
        $trigger_value1 = $page->findField('checkboxes_trigger[value1]');
        $this->assertNotEmpty($trigger_value1);
        $trigger_value2 = $page->findField('checkboxes_trigger[value2]');
        $this->assertNotEmpty($trigger_value2);
        $trigger_value3 = $page->findField('checkboxes_trigger[value3]');
        $this->assertNotEmpty($trigger_value3);
        $textfield_visible_value2 = $page->findField('textfield_visible_when_checkboxes_trigger_value2_checked');
        $this->assertNotEmpty($textfield_visible_value2);
        $textfield_visible_value3 = $page->findField('textfield_visible_when_checkboxes_trigger_value3_checked');
        $this->assertNotEmpty($textfield_visible_value3);
        // Verify initial state.
        $this->assertFalse($textfield_visible_value2->isVisible());
        $this->assertFalse($textfield_visible_value3->isVisible());
        // Change state: check the 'Value 1' checkbox.
        $trigger_value1->check();
        $this->assertFalse($textfield_visible_value2->isVisible());
        $this->assertFalse($textfield_visible_value3->isVisible());
        // Change state: check the 'Value 2' checkbox.
        $trigger_value2->check();
        $this->assertTrue($textfield_visible_value2->isVisible());
        $this->assertFalse($textfield_visible_value3->isVisible());
        // Change state: check the 'Value 3' checkbox.
        $trigger_value3->check();
        $this->assertTrue($textfield_visible_value2->isVisible());
        $this->assertTrue($textfield_visible_value3->isVisible());
        // Change state: uncheck the 'Value 2' checkbox.
        $trigger_value2->uncheck();
        $this->assertFalse($textfield_visible_value2->isVisible());
        $this->assertTrue($textfield_visible_value3->isVisible());
    }
    
    /**
     * Tests states of elements triggered by a textfield element.
     */
    protected function doTextfieldTriggerTests() {
        $this->drupalGet('form-test/javascript-states-form');
        $page = $this->getSession()
            ->getPage();
        // Find trigger and target elements.
        $trigger = $page->findField('textfield_trigger');
        $this->assertNotEmpty($trigger);
        $checkbox_checked_target = $page->findField('checkbox_checked_when_textfield_trigger_filled');
        $this->assertNotEmpty($checkbox_checked_target);
        $checkbox_unchecked_target = $page->findField('checkbox_unchecked_when_textfield_trigger_filled');
        $this->assertNotEmpty($checkbox_unchecked_target);
        $select_invisible_target = $page->findField('select_invisible_when_textfield_trigger_filled');
        $this->assertNotEmpty($select_invisible_target);
        $select_visible_target = $page->findField('select_visible_when_textfield_trigger_filled');
        $this->assertNotEmpty($select_visible_target);
        $textfield_required_target = $page->findField('textfield_required_when_textfield_trigger_filled');
        $this->assertNotEmpty($textfield_required_target);
        $details = $this->assertSession()
            ->elementExists('css', '#edit-details-expanded-when-textfield-trigger-filled');
        $textfield_in_details = $details->findField('textfield_in_details');
        $this->assertNotEmpty($textfield_in_details);
        // Verify initial state.
        $this->assertFalse($checkbox_checked_target->isChecked());
        $this->assertTrue($checkbox_unchecked_target->isChecked());
        $this->assertTrue($select_invisible_target->isVisible());
        $this->assertFalse($select_visible_target->isVisible());
        $this->assertFalse($textfield_required_target->hasAttribute('required'));
        $this->assertFalse($details->hasAttribute('open'));
        $this->assertFalse($textfield_in_details->isVisible());
        // Change state: fill the textfield.
        $trigger->setValue('filled');
        // Verify triggered state.
        $this->assertTrue($checkbox_checked_target->isChecked());
        $this->assertFalse($checkbox_unchecked_target->isChecked());
        $this->assertFalse($select_invisible_target->isVisible());
        $this->assertTrue($select_visible_target->isVisible());
        $this->assertEquals('required', $textfield_required_target->getAttribute('required'));
        $this->assertTrue($details->hasAttribute('open'));
        $this->assertTrue($textfield_in_details->isVisible());
    }
    
    /**
     * Tests states of elements triggered by a radios element.
     */
    protected function doRadiosTriggerTests() {
        $this->drupalGet('form-test/javascript-states-form');
        $page = $this->getSession()
            ->getPage();
        // Find trigger and target elements.
        $trigger = $page->findField('radios_trigger');
        $this->assertNotEmpty($trigger);
        $fieldset_visible_when_value2 = $this->assertSession()
            ->elementExists('css', '#edit-fieldset-visible-when-radios-trigger-has-value2');
        $textfield_in_fieldset = $fieldset_visible_when_value2->findField('textfield_in_fieldset');
        $this->assertNotEmpty($textfield_in_fieldset);
        $checkbox_checked_target = $page->findField('checkbox_checked_when_radios_trigger_has_value3');
        $this->assertNotEmpty($checkbox_checked_target);
        $checkbox_unchecked_target = $page->findField('checkbox_unchecked_when_radios_trigger_has_value3');
        $this->assertNotEmpty($checkbox_unchecked_target);
        $textfield_invisible_target = $page->findField('textfield_invisible_when_radios_trigger_has_value2');
        $this->assertNotEmpty($textfield_invisible_target);
        $select_required_target = $page->findField('select_required_when_radios_trigger_has_value2');
        $this->assertNotEmpty($select_required_target);
        $details = $this->assertSession()
            ->elementExists('css', '#edit-details-expanded-when-radios-trigger-has-value3');
        $textfield_in_details = $details->findField('textfield_in_details');
        $this->assertNotEmpty($textfield_in_details);
        // Verify initial state, both the fieldset and something inside it.
        $this->assertFalse($fieldset_visible_when_value2->isVisible());
        $this->assertFalse($textfield_in_fieldset->isVisible());
        $this->assertFalse($checkbox_checked_target->isChecked());
        $this->assertTrue($checkbox_unchecked_target->isChecked());
        $this->assertTrue($textfield_invisible_target->isVisible());
        $this->assertFalse($select_required_target->hasAttribute('required'));
        $this->assertFalse($details->hasAttribute('open'));
        $this->assertFalse($textfield_in_details->isVisible());
        // Change state: select the value2 radios option.
        $trigger->selectOption('value2');
        // Verify triggered state.
        $this->assertTrue($fieldset_visible_when_value2->isVisible());
        $this->assertTrue($textfield_in_fieldset->isVisible());
        $this->assertFalse($textfield_invisible_target->isVisible());
        $this->assertTrue($select_required_target->hasAttribute('required'));
        // Checkboxes and details should not have changed state, yet.
        $this->assertFalse($checkbox_checked_target->isChecked());
        $this->assertTrue($checkbox_unchecked_target->isChecked());
        $this->assertFalse($details->hasAttribute('open'));
        $this->assertFalse($textfield_in_details->isVisible());
        // Change state: select the value3 radios option.
        $trigger->selectOption('value3');
        // Fieldset and contents should re-disappear.
        $this->assertFalse($fieldset_visible_when_value2->isVisible());
        $this->assertFalse($textfield_in_fieldset->isVisible());
        // Textfield and select should revert to initial state.
        $this->assertTrue($textfield_invisible_target->isVisible());
        $this->assertFalse($select_required_target->hasAttribute('required'));
        // Checkbox states should now change.
        $this->assertTrue($checkbox_checked_target->isChecked());
        $this->assertFalse($checkbox_unchecked_target->isChecked());
        // Details should now be expanded.
        $this->assertTrue($details->hasAttribute('open'));
        $this->assertTrue($textfield_in_details->isVisible());
    }
    
    /**
     * Tests states of elements triggered by a select element.
     */
    protected function doSelectTriggerTests() {
        $this->drupalGet('form-test/javascript-states-form');
        $page = $this->getSession()
            ->getPage();
        // Find trigger and target elements.
        $trigger = $page->findField('select_trigger');
        $this->assertNotEmpty($trigger);
        $item_visible_value2 = $this->assertSession()
            ->elementExists('css', '#edit-item-visible-when-select-trigger-has-value2');
        $textfield_visible_value3 = $page->findField('textfield_visible_when_select_trigger_has_value3');
        $this->assertNotEmpty($textfield_visible_value3);
        $textfield_visible_value2_or_value3 = $page->findField('textfield_visible_when_select_trigger_has_value2_or_value3');
        $this->assertNotEmpty($textfield_visible_value2_or_value3);
        // Verify initial state.
        $this->assertFalse($item_visible_value2->isVisible());
        $this->assertFalse($textfield_visible_value3->isVisible());
        $this->assertFalse($textfield_visible_value2_or_value3->isVisible());
        // Change state: select the 'Value 2' option.
        $trigger->setValue('value2');
        $this->assertTrue($item_visible_value2->isVisible());
        $this->assertFalse($textfield_visible_value3->isVisible());
        $this->assertTrue($textfield_visible_value2_or_value3->isVisible());
        // Change state: select the 'Value 3' option.
        $trigger->setValue('value3');
        $this->assertFalse($item_visible_value2->isVisible());
        $this->assertTrue($textfield_visible_value3->isVisible());
        $this->assertTrue($textfield_visible_value2_or_value3->isVisible());
    }
    
    /**
     * Tests states of elements triggered by multiple elements.
     */
    protected function doMultipleTriggerTests() {
        $this->drupalGet('form-test/javascript-states-form');
        $page = $this->getSession()
            ->getPage();
        // Find trigger and target elements.
        $select_trigger = $page->findField('select_trigger');
        $this->assertNotEmpty($select_trigger);
        $textfield_trigger = $page->findField('textfield_trigger');
        $this->assertNotEmpty($textfield_trigger);
        $item_visible_value2_and_textfield = $this->assertSession()
            ->elementExists('css', '#edit-item-visible-when-select-trigger-has-value2-and-textfield-trigger-filled');
        // Verify initial state.
        $this->assertFalse($item_visible_value2_and_textfield->isVisible());
        // Change state: select the 'Value 2' option.
        $select_trigger->setValue('value2');
        $this->assertFalse($item_visible_value2_and_textfield->isVisible());
        // Change state: fill the textfield.
        $textfield_trigger->setValue('filled');
        $this->assertTrue($item_visible_value2_and_textfield->isVisible());
    }
    
    /**
     * Tests states of radios element triggered by other radios element.
     */
    protected function doNestedTriggerTests() {
        $this->drupalGet('form-test/javascript-states-form');
        $page = $this->getSession()
            ->getPage();
        // Find trigger and target elements.
        $radios_opposite1 = $page->findField('radios_opposite1');
        $this->assertNotEmpty($radios_opposite1);
        $radios_opposite2 = $page->findField('radios_opposite2');
        $this->assertNotEmpty($radios_opposite2);
        // Verify initial state.
        $this->assertEquals('0', $radios_opposite1->getValue());
        $this->assertEquals('1', $radios_opposite2->getValue());
        // Set $radios_opposite2 value to 0, $radios_opposite1 value should be 1.
        $radios_opposite2->setValue('0');
        $this->assertEquals('1', $radios_opposite1->getValue());
        // Set $radios_opposite1 value to 1, $radios_opposite2 value should be 0.
        $radios_opposite1->setValue('0');
        $this->assertEquals('1', $radios_opposite2->getValue());
    }

}