feat(popup): 🚸 add extension update alert (#62)

Squashed commit of the following:

commit 3b9137c
Author: James <james@jamesnzl.xyz>
Date:   Thu Jul 21 02:10:24 2022 +1200

    feat(popup): :children_crossing: add 'what's new' alert

commit 135ef41
Author: James <james@jamesnzl.xyz>
Date:   Thu Jul 21 02:02:38 2022 +1200

    feat(storage): :card_file_box: add storage key for last update version

src/apis/storage.ts

@@ -10,9 +10,18 @@ const KEYS = <const>{
 	course: 'savedCourse',
 	assignments: 'savedAssignments',
 	oauthState: 'oauthState',
+	lastVersion: 'lastVersion',
 };
 
 export const Storage = <const>{
+	async getLastVersion(): Promise<string> {
+		return (await browser.storage.local.get(KEYS.lastVersion))[KEYS.lastVersion];
+	},
+
+	async setLastVersion(version: string) {
+		return await browser.storage.local.set({ [KEYS.lastVersion]: version });
+	},
+
 	async getOAuthState(): Promise<string> {
 		return (await browser.storage.local.get(KEYS.oauthState))[KEYS.oauthState];
 	},

src/popup/popup.ts

@@ -282,4 +282,15 @@ Storage.getStorageKey('notion.propertyNames.status', false).then(value => {
 	if (!deleteProperty) return;
 
 	Storage.clearStorageKey('notion.propertyNames.status');
+});
+
+// * what's new alert
+Storage.getLastVersion().then(version => {
+	const { version: manifestVersion } = browser.runtime.getManifest();
+
+	if (version === manifestVersion) return;
+
+	alert(`Your extension has been updated to v${manifestVersion}!\n\nTo see what's new, visit the store page, the Discord Server, or the GitHub Repository.`);
+
+	Storage.setLastVersion(manifestVersion);
 });