feat: add 15 new WCAG rules, dynamic ARIA checks and bump version to v3.1.4

2026-07-30 20:34:41 +03:00
parent 164828f9f7
commit 58b1618d96
31 changed files with 1138 additions and 1 deletions
@@ -0,0 +1,38 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class AnchorMissingHref extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_ANCHOR_HREF'; }
+    public function getDescription(): string { return 'Anchor elements (<a>) acting as links must have a valid href attribute.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'a') {
+            return null;
+        }
+
+        if ($element->hasAttribute('name') || $element->hasAttribute('role')) {
+            return null;
+        }
+
+        if (!$element->hasAttribute('href') || trim($element->getAttribute('href')) === '') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add a valid href attribute to the <a> element, or use a <button> element if it triggers an action.'
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,30 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class AppletBanned extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_APPLET_BANNED'; }
+    public function getDescription(): string { return 'The <applet> element is obsolete and non-accessible. Use modern HTML5 elements instead.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 1; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) === 'applet') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Remove the <applet> element and replace it with modern HTML5 or accessible media embeddings.'
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,54 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class AriaExpandedState extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_ARIA_EXPANDED'; }
+    public function getDescription(): string { return 'Collapsible toggle buttons (accordion, dropdown, collapse) must have an aria-expanded attribute.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        $tagName = strtolower($element->tagName);
+        $role = strtolower($element->getAttribute('role'));
+
+        if ($tagName !== 'button' && $tagName !== 'a' && $role !== 'button') {
+            return null;
+        }
+
+        $class = strtolower($element->getAttribute('class'));
+        $dataBsToggle = strtolower($element->getAttribute('data-bs-toggle'));
+        $dataToggle = strtolower($element->getAttribute('data-toggle'));
+
+        $isCollapsible = str_contains($class, 'dropdown-toggle') || 
+                         str_contains($class, 'accordion-button') || 
+                         str_contains($class, 'collapse-toggle') ||
+                         in_array($dataBsToggle, ['collapse', 'dropdown', 'offcanvas'], true) ||
+                         in_array($dataToggle, ['collapse', 'dropdown'], true);
+
+        if (!$isCollapsible) {
+            return null;
+        }
+
+        if ($element->hasAttribute('aria-expanded')) {
+            $val = strtolower($element->getAttribute('aria-expanded'));
+            if (in_array($val, ['true', 'false'], true)) {
+                return null;
+            }
+        }
+
+        return $this->createViolation(
+            $element,
+            $this->getDescription(),
+            'Add aria-expanded="false" (or "true") to the toggle element so screen readers announce expanded/collapsed status.'
+        );
+    }
+}
@@ -0,0 +1,35 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class AriaHiddenBody extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_ARIA_HIDDEN_BODY'; }
+    public function getDescription(): string { return 'The <body> or <html> element must not have aria-hidden="true".'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 1; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        $tagName = strtolower($element->tagName);
+        if ($tagName !== 'body' && $tagName !== 'html') {
+            return null;
+        }
+
+        if (strtolower($element->getAttribute('aria-hidden')) === 'true') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Remove aria-hidden="true" from the <body>/<html> tag to prevent hiding the entire document from screen readers.'
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,55 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class AriaLiveStatus extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_3_STATUS_MESSAGES'; }
+    public function getDescription(): string { return 'Dynamic status containers and toast messages must use aria-live or implicit live roles.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::AA; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        $class = strtolower($element->getAttribute('class'));
+        $role = strtolower($element->getAttribute('role'));
+
+        $statusClasses = ['toast', 'status-message', 'loading-message', 'alert-message', 'live-region'];
+        $isStatusContainer = false;
+
+        foreach ($statusClasses as $statusClass) {
+            if (str_contains($class, $statusClass)) {
+                $isStatusContainer = true;
+                break;
+            }
+        }
+
+        if (!$isStatusContainer) {
+            return null;
+        }
+
+        // Implicit live roles in ARIA include status, alert, log
+        if (in_array($role, ['status', 'alert', 'log'], true)) {
+            return null;
+        }
+
+        if ($element->hasAttribute('aria-live')) {
+            $liveVal = strtolower($element->getAttribute('aria-live'));
+            if (in_array($liveVal, ['polite', 'assertive'], true)) {
+                return null;
+            }
+        }
+
+        return $this->createViolation(
+            $element,
+            $this->getDescription(),
+            'Add aria-live="polite" (or role="status"/role="alert") so screen readers dynamically announce updates to users.'
+        );
+    }
+}
@@ -0,0 +1,49 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class AriaPressedToggle extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_TOGGLE_BUTTON_STATE'; }
+    public function getDescription(): string { return 'Toggle buttons must use aria-pressed="true" or "false" to communicate state changes.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 3; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        $tagName = strtolower($element->tagName);
+        $role = strtolower($element->getAttribute('role'));
+
+        if ($tagName !== 'button' && $role !== 'button') {
+            return null;
+        }
+
+        $class = strtolower($element->getAttribute('class'));
+        $dataToggle = strtolower($element->getAttribute('data-toggle'));
+
+        $isToggleButton = str_contains($class, 'btn-toggle') || str_contains($class, 'toggle-btn') || $dataToggle === 'button';
+
+        if (!$isToggleButton) {
+            return null;
+        }
+
+        if ($element->hasAttribute('aria-pressed')) {
+            $val = strtolower($element->getAttribute('aria-pressed'));
+            if (in_array($val, ['true', 'false', 'mixed'], true)) {
+                return null;
+            }
+        }
+
+        return $this->createViolation(
+            $element,
+            $this->getDescription(),
+            'Add aria-pressed="true" or aria-pressed="false" to indicate the toggle state to assistive technology.'
+        );
+    }
+}
@@ -0,0 +1,58 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class ButtonLoadingState extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_BUTTON_LOADING_STATE'; }
+    public function getDescription(): string { return 'Buttons displaying loading spinners must inform screen readers via aria-busy or aria-label.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 3; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        $tagName = strtolower($element->tagName);
+        $role = strtolower($element->getAttribute('role'));
+
+        if ($tagName !== 'button' && $role !== 'button') {
+            return null;
+        }
+
+        $class = strtolower($element->getAttribute('class'));
+        $hasLoadingClass = str_contains($class, 'loading') || str_contains($class, 'spinner') || str_contains($class, 'is-busy');
+        
+        $hasSpinnerChild = false;
+        foreach ($element->getElementsByTagName('*') as $child) {
+            $childClass = strtolower($child->getAttribute('class'));
+            if (str_contains($childClass, 'spinner') || str_contains($childClass, 'loading') || str_contains($childClass, 'loader')) {
+                $hasSpinnerChild = true;
+                break;
+            }
+        }
+
+        if (!$hasLoadingClass && !$hasSpinnerChild && strtolower($element->getAttribute('aria-busy')) !== 'true') {
+            return null;
+        }
+
+        // Must have aria-busy="true" or an explicit aria-label/aria-live describing the loading process
+        $hasAriaBusy = strtolower($element->getAttribute('aria-busy')) === 'true';
+        $hasAriaLive = $element->hasAttribute('aria-live');
+        $hasAriaLabel = $element->hasAttribute('aria-label') && trim($element->getAttribute('aria-label')) !== '';
+
+        if ($hasAriaBusy || ($hasAriaLabel && $hasAriaLive)) {
+            return null;
+        }
+
+        return $this->createViolation(
+            $element,
+            $this->getDescription(),
+            'Add aria-busy="true" and an aria-label (e.g. aria-label="Loading...") to the button when an async action is in progress.'
+        );
+    }
+}
@@ -0,0 +1,35 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class FigureCaptionStructure extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_FIGCAPTION_PARENT'; }
+    public function getDescription(): string { return '<figcaption> elements must be direct children of a <figure> element.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'figcaption') {
+            return null;
+        }
+
+        $parent = $element->parentNode;
+        if (!$parent instanceof DOMElement || strtolower($parent->tagName) !== 'figure') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Wrap the <figcaption> element inside a parent <figure> element or change it to a standard paragraph/caption element.'
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,42 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class FocusableWithoutRole extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_FOCUSABLE_ROLE'; }
+    public function getDescription(): string { return 'Non-interactive focusable elements (with tabindex >= 0) must have an explicit ARIA role.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 3; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (!$element->hasAttribute('tabindex')) {
+            return null;
+        }
+
+        $tabindex = (int)$element->getAttribute('tabindex');
+        if ($tabindex < 0) {
+            return null;
+        }
+
+        $tagName = strtolower($element->tagName);
+        $nonInteractiveTags = ['div', 'span', 'p', 'li', 'section', 'article', 'td', 'th', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6'];
+        
+        if (in_array($tagName, $nonInteractiveTags, true) && !$element->hasAttribute('role')) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                sprintf('Add an appropriate ARIA role (e.g., role="button", role="link") to the focusable <%s> element.', $tagName)
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,55 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class InputMissingAutocomplete extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_5_INPUT_AUTOCOMPLETE'; }
+    public function getDescription(): string { return 'Input fields collecting personal data should have an autocomplete attribute.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::AA; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 3; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'input') {
+            return null;
+        }
+
+        $type = strtolower($element->getAttribute('type'));
+        if (in_array($type, ['hidden', 'submit', 'button', 'reset', 'checkbox', 'radio', 'image', 'file'], true)) {
+            return null;
+        }
+
+        $name = strtolower($element->getAttribute('name'));
+        $id = strtolower($element->getAttribute('id'));
+        $targetKeywords = ['email', 'phone', 'tel', 'username', 'user', 'password', 'pass', 'address', 'zip', 'city', 'country', 'name', 'fname', 'lname'];
+
+        $isPersonalField = false;
+        if (in_array($type, ['email', 'tel'], true)) {
+            $isPersonalField = true;
+        } else {
+            foreach ($targetKeywords as $keyword) {
+                if (str_contains($name, $keyword) || str_contains($id, $keyword)) {
+                    $isPersonalField = true;
+                    break;
+                }
+            }
+        }
+
+        if ($isPersonalField && (!$element->hasAttribute('autocomplete') || trim($element->getAttribute('autocomplete')) === '')) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add an autocomplete attribute (e.g., autocomplete="email", autocomplete="username") to improve accessibility and user experience.'
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,46 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class ListItemParent extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_LIST_ITEM_PARENT'; }
+    public function getDescription(): string { return 'List items (<li>) must be contained inside a parent <ul>, <ol>, or <menu> element.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'li') {
+            return null;
+        }
+
+        $parent = $element->parentNode;
+        if (!$parent instanceof DOMElement) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Wrap the orphan <li> element in a parent <ul> or <ol> tag.'
+            );
+        }
+
+        $parentTag = strtolower($parent->tagName);
+        $validParents = ['ul', 'ol', 'menu'];
+
+        if (!in_array($parentTag, $validParents, true) && strtolower($parent->getAttribute('role')) !== 'list') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                sprintf('Move the <li> element inside a <ul> or <ol> container instead of <%s>.', $parentTag)
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,34 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class OptgroupLabel extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_OPTGROUP_LABEL'; }
+    public function getDescription(): string { return '<optgroup> elements must have a non-empty label attribute.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'optgroup') {
+            return null;
+        }
+
+        if (!$element->hasAttribute('label') || trim($element->getAttribute('label')) === '') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add a descriptive label attribute to the <optgroup> element.'
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,59 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class RadioGroupFieldset extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_RADIO_GROUP_FIELDSET'; }
+    public function getDescription(): string { return 'Radio button groups sharing the same name should be grouped inside a <fieldset> with a <legend> or role="radiogroup".'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 3; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'input') {
+            return null;
+        }
+
+        if (strtolower($element->getAttribute('type')) !== 'radio') {
+            return null;
+        }
+
+        $name = $element->getAttribute('name');
+        if ($name === '') {
+            return null;
+        }
+
+        // Check if ancestor is fieldset or role="radiogroup"
+        $current = $element->parentNode;
+        while ($current instanceof DOMElement) {
+            $parentTag = strtolower($current->tagName);
+            $parentRole = strtolower($current->getAttribute('role'));
+
+            if ($parentTag === 'fieldset') {
+                $legends = $current->getElementsByTagName('legend');
+                if ($legends->length > 0) {
+                    return null;
+                }
+            }
+
+            if ($parentRole === 'radiogroup' && ($current->hasAttribute('aria-label') || $current->hasAttribute('aria-labelledby'))) {
+                return null;
+            }
+
+            $current = $current->parentNode;
+        }
+
+        return $this->createViolation(
+            $element,
+            $this->getDescription(),
+            sprintf('Wrap radio inputs named "%s" inside a <fieldset> with a <legend> to group related radio choices.', $name)
+        );
+    }
+}
@@ -0,0 +1,35 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class SummaryParent extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_SUMMARY_PARENT'; }
+    public function getDescription(): string { return '<summary> elements must be direct children of a <details> element.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'summary') {
+            return null;
+        }
+
+        $parent = $element->parentNode;
+        if (!$parent instanceof DOMElement || strtolower($parent->tagName) !== 'details') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Wrap the <summary> element inside a <details> element or change it to a standard heading/button.'
+            );
+        }
+
+        return null;
+    }
+}
@@ -0,0 +1,41 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class TableMultiCaption extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_TABLE_MULTI_CAPTION'; }
+    public function getDescription(): string { return 'A <table> element must not contain more than one <caption> element.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'table') {
+            return null;
+        }
+
+        $captionCount = 0;
+        foreach ($element->childNodes as $child) {
+            if ($child instanceof DOMElement && strtolower($child->tagName) === 'caption') {
+                $captionCount++;
+            }
+        }
+
+        if ($captionCount > 1) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Remove duplicate <caption> elements so that the table has at most one caption.'
+            );
+        }
+
+        return null;
+    }
+}