New comments can be created

app/javascript/components/Comments/NewComment.tsx

@@ -0,0 +1,28 @@
+import * as React from 'react';
+import { FormEvent } from 'react';
+
+import Button from '../shared/Button';
+
+interface Props {
+  body: string;
+  parentId: number;
+  handleChange(e: FormEvent): void;
+  handleSubmit(body: string, parentId: number): void;
+}
+
+const NewComment = ({
+  body,
+  parentId,
+  handleChange,
+  handleSubmit,
+}: Props) => (
+  <div className="newCommentForm">
+    <textarea
+      value={body}
+      onChange={handleChange}
+    />
+    <Button onClick={() => handleSubmit(body, parentId)}>Submit</Button>
+  </div>
+);
+
+export default NewComment;