fix: Accordion Component not collapsing when toggled twice

Fixes #3726

src/AccordionToggle.js

@@ -1,6 +1,7 @@
 import React, { useContext } from 'react';
 import PropTypes from 'prop-types';
 import SelectableContext from './SelectableContext';
+import AccordionContext from './AccordionContext';
 
 const propTypes = {
   /** Set a custom element for this component */
@@ -31,13 +32,20 @@ const AccordionToggle = React.forwardRef(
     },
     ref,
   ) => {
+    const contextEventKey = useContext(AccordionContext);
     const onSelect = useContext(SelectableContext);
 
     return (
       <Component
         ref={ref}
         onClick={e => {
-          onSelect(eventKey, e);
+          /* 
+            Compare the event key in context with the given event key.
+            If they are the same, then collapse the component.
+          */
+          let eventKeyPassed = eventKey === contextEventKey ? null : eventKey;
+
+          onSelect(eventKeyPassed, e);
           if (onClick) onClick(e);
         }}
         {...props}