Re-introduce accessibility tests

test/test.js

@@ -1,4 +1,4 @@
-import {assert} from '@open-wc/testing'
+import {assert, expect} from '@open-wc/testing'
 import '../src/index.ts'
 
 describe('tab-container', function () {
@@ -68,9 +68,16 @@ describe('tab-container', function () {
     })
 
     afterEach(function () {
+      // Check to make sure we still have accessible markup after the test finishes running.
+      expect(document.body).to.be.accessible()
+
       document.body.innerHTML = ''
     })
 
+    it('has accessible markup', function () {
+      expect(document.body).to.be.accessible()
+    })
+
     it('the second tab is still selected', function () {
       assert.deepStrictEqual(tabs.map(isSelected), [false, true, false], 'Second tab is selected')
       assert.deepStrictEqual(panels.map(isHidden), [true, false, true], 'Second panel is visible')
@@ -100,9 +107,16 @@ describe('tab-container', function () {
     })
 
     afterEach(function () {
+      // Check to make sure we still have accessible markup after the test finishes running.
+      expect(document.body).to.be.accessible()
+
       document.body.innerHTML = ''
     })
 
+    it('has accessible markup', function () {
+      expect(document.body).to.be.accessible()
+    })
+
     it('the second tab is still selected', function () {
       assert.deepStrictEqual(tabs.map(isSelected), [false, true, false], 'Second tab is selected')
       assert.deepStrictEqual(panels.map(isHidden), [true, false, true], 'Second panel is visible')
@@ -138,9 +152,16 @@ describe('tab-container', function () {
     })
 
     afterEach(function () {
+      // Check to make sure we still have accessible markup after the test finishes running.
+      expect(document.body).to.be.accessible()
+
       document.body.innerHTML = ''
     })
 
+    it('has accessible markup', function () {
+      expect(document.body).to.be.accessible()
+    })
+
     it('click works and `tab-container-changed` event is dispatched', function () {
       tabs[1].click()
       assert.deepStrictEqual(tabs.map(isSelected), [false, true, false], 'Second tab is selected')
@@ -331,9 +352,16 @@ describe('tab-container', function () {
     })
 
     afterEach(function () {
+      // Check to make sure we still have accessible markup after the test finishes running.
+      expect(document.body).to.be.accessible()
+
       document.body.innerHTML = ''
     })
 
+    it('has accessible markup', function () {
+      expect(document.body).to.be.accessible()
+    })
+
     it('only switches closest tab-containers on click', () => {
       assert.deepStrictEqual(tabs.map(isSelected), [true, false, false])
       assert.deepStrictEqual(nestedTabs.map(isSelected), [true, false])