Add unit tests for AccordionItemState component

Author: ryami333

src/components/AccordionItemState.spec.tsx

@@ -0,0 +1,56 @@
+import * as React from 'react';
+import { render } from 'react-testing-library';
+import Accordion from './Accordion';
+import AccordionItem from './AccordionItem';
+import AccordionItemState from './AccordionItemState';
+
+enum UUIDS {
+    FOO = 'FOO',
+    BAR = 'BAR',
+}
+
+describe('ItemContext', () => {
+    describe('render prop', () => {
+        it('renders', () => {
+            const { getByText } = render(
+                <Accordion>
+                    <AccordionItem>
+                        <AccordionItemState>
+                            {(): string => 'Hello World'}
+                        </AccordionItemState>
+                    </AccordionItem>
+                </Accordion>,
+            );
+
+            expect(getByText('Hello World')).toBeTruthy();
+        });
+
+        it('invokes the render prop with the contextual item’s expanded state', () => {
+            const { getByTestId } = render(
+                <Accordion preExpanded={[UUIDS.FOO]}>
+                    <AccordionItem uuid={UUIDS.FOO}>
+                        <AccordionItemState>
+                            {(expanded: boolean): JSX.Element => (
+                                <div data-testid={UUIDS.FOO}>
+                                    {expanded && 'expanded'}
+                                </div>
+                            )}
+                        </AccordionItemState>
+                    </AccordionItem>
+                    <AccordionItem uuid={UUIDS.BAR}>
+                        <AccordionItemState>
+                            {(expanded: boolean): JSX.Element => (
+                                <div data-testid={UUIDS.BAR}>
+                                    {expanded && 'expanded'}
+                                </div>
+                            )}
+                        </AccordionItemState>
+                    </AccordionItem>
+                </Accordion>,
+            );
+
+            expect(getByTestId(UUIDS.FOO).textContent).toEqual('expanded');
+            expect(getByTestId(UUIDS.BAR).textContent).toEqual('');
+        });
+    });
+});

src/components/AccordionItemState.tsx

@@ -3,11 +3,10 @@ import { DivAttributes } from '../helpers/types';
 import { Consumer as ItemConsumer, ItemContext } from './ItemContext';
 
 type Props = Pick<DivAttributes, Exclude<keyof DivAttributes, 'children'>> & {
-    expanded: boolean;
-    children(expanded: boolean): JSX.Element;
+    children(expanded?: boolean): React.ReactNode;
 };
 
-export default class AccordionItemStateWrapper extends React.Component<Props> {
+export default class AccordionItemState extends React.Component<Props> {
     renderChildren = (itemContext: ItemContext): JSX.Element => {
         const { expanded } = itemContext;