fix(accordion)!: remove BaseAccordion

.changeset/heavy-peas-appear.md

@@ -0,0 +1,18 @@
+---
+"@patternfly/pfe-tools": minor
+---
+Added `querySnapshot` accessibility testing helper
+
+```ts
+
+describe('then clicking the toggle', function() {
+  beforeEach(async function() {
+    await clickElementAtCenter(toggle);
+  });
+  it('expands the disclosure panel', async function() {
+    const snapshot = await a11ySnapshot();
+    const expanded = querySnapshot(snapshot, { expanded: true });
+    expect(expanded).to.be.ok;
+  });
+});
+```

.changeset/hip-coins-prove.md

@@ -0,0 +1,32 @@
+---
+"@patternfly/elements": major
+---
+`<pf-accordion>`: Removed `BaseAccordion*` classes, as well as static `isPanel`, `isHeader`, and `isAccordion` methods. Removed the optional `parentAccordion` parameter to `PfAccordion#expand(index)`. Renamed accordion event classes by adding the `Pf` prefix:
+
+**Before**:
+
+```js
+import {
+  AccordionHeaderChangeEvent
+} from '@patternfly/elements/pf-accordion/pf-accordion.js';
+
+addEventListener('change', function(event) {
+  if (event instanceof AccordionHeaderChangeEvent) {
+    // ...
+  }
+});
+```
+
+**After**:
+
+```js
+import {
+  PfAccordionHeaderChangeEvent
+} from '@patternfly/elements/pf-accordion/pf-accordion.js';
+
+addEventListener('change', function(event) {
+  if (event instanceof PfAccordionHeaderChangeEvent) {
+    // ...
+  }
+});
+```