Save the sessionId clientside

We need a way for users to reconnect to their serverside session if
their connection drops or they leave the page and return.
We use sessionStorage so that the session is not shared across tabs as
it would be for localStorage.
We receive the "session:set" event from the server which tells us the
server has save the session and now it's time for the client to do the
same.
We use the "DOMContentLoaded" event to attempt to read the sessionId
from localStorage, if it exists then we connect. If it doesn't exist the
user will have to manually connect by entering their name.

Co-authored-by: Ynda Jas <ynda@dxw.com>
Co-authored-by: George Eaton <george@dxw.com>
Co-authored-by: Liz Daly <liz.daly@dxw.com>

client/index.ts

@@ -106,13 +106,27 @@ socket.on("scoresAndBonusPoints:get", (playerScores, bonusPoints) => {
 	renderBonusPoints(bonusPoints);
 });
 
+socket.on("session:set", (session) => {
+	socket.auth = { sessionId: session.id };
+	sessionStorage.setItem("sessionId", session.id);
+});
+
 const nameFormElement = getElementById<NameFormElement>("name-form");
 
 const roundResetButtonElement =
 	getElementById<HTMLButtonElement>("round-reset-button");
 
 const startButtonElement = getElementById<HTMLButtonElement>("start-button");
 
+window.document.addEventListener("DOMContentLoaded", () => {
+	const sessionId = sessionStorage.getItem("sessionId");
+
+	if (sessionId) {
+		socket.auth = { sessionId };
+		socket.connect();
+	}
+});
+
 nameFormElement.addEventListener("submit", (e) => {
 	e.preventDefault();
 	addPlayer(socket, nameFormElement.elements.name.value);