refactor(sw): Typecheck the service worker (#9314)

* Typecheck the service worker

Currently the service worker build never typechecks, since esbuild and typescript-eslint don't do such job.

esbuild: https://esbuild.github.io/content-types/#typescript

>However, esbuild does not do any type checking so you will still need to run tsc -noEmit in parallel with esbuild to check types. This is not something esbuild does itself.

typescript-eslint: https://typescript-eslint.io/linting/troubleshooting#why-dont-i-see-typescript-errors-in-my-eslint-output

>TypeScript's compiler (or whatever your build chain may be) is specifically designed and built to validate the correctness of your codebase. Our tooling does not reproduce the errors that TypeScript provides, because doing so would slow down the lint run [1], and duplicate the errors that TypeScript already outputs for you.

Adding this step adds tons of TS errors 😱

* Override lib-webworker with service worker

packages/sw/package.json

@@ -4,7 +4,7 @@
 	"scripts": {
 		"watch": "node build.js watch",
 		"build": "node build.js",
-		"lint": "eslint --quiet src/**/*.ts"
+		"lint": "tsc --noEmit && eslint --quiet src/**/*.ts"
 	},
 	"dependencies": {
 		"esbuild": "^0.14.42",
@@ -13,7 +13,9 @@
 	},
 	"devDependencies": {
 		"@typescript-eslint/parser": "^5.45.0",
+		"@typescript/lib-webworker": "npm:@types/serviceworker@^0.0.58",
 		"eslint": "^8.16.0",
-		"eslint-plugin-import": "^2.26.0"
+		"eslint-plugin-import": "^2.26.0",
+		"typescript": "4.9.4"
 	}
 }

packages/sw/src/scripts/create-notification.ts

@@ -1,11 +1,6 @@
 /*
  * Notification manager for SW
  */
-
-// TODO: remove this declaration when https://github.com/microsoft/TypeScript/issues/11781 closes
-// eslint-disable-next-line no-var
-declare var self: ServiceWorkerGlobalScope;
-
 import { swLang } from '@/scripts/lang';
 import { cli } from '@/scripts/operations';
 import { pushNotificationDataMap } from '@/types';

packages/sw/src/scripts/operations.ts

@@ -2,11 +2,6 @@
  * Operations
  * 各種操作
  */
-
-// TODO: remove this declaration when https://github.com/microsoft/TypeScript/issues/11781 closes
-// eslint-disable-next-line no-var
-declare var self: ServiceWorkerGlobalScope;
-
 import * as Misskey from 'misskey-js';
 import { SwMessage, swMessageOrderType } from '@/types';
 import { acct as getAcct } from '@/filters/user';

packages/sw/src/sw.ts

@@ -1,7 +1,3 @@
-// TODO: remove this declaration when https://github.com/microsoft/TypeScript/issues/11781 closes
-// eslint-disable-next-line no-var
-declare var self: ServiceWorkerGlobalScope;
-
 import { createEmptyNotification, createNotification } from '@/scripts/create-notification';
 import { swLang } from '@/scripts/lang';
 import { swNotificationRead } from '@/scripts/notification-read';

yarn.lock

@@ -3009,6 +3009,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@typescript/lib-webworker@npm:@types/serviceworker@^0.0.58":
+  version: 0.0.58
+  resolution: "@types/serviceworker@npm:0.0.58"
+  checksum: d6aa73d02854968ccaa0fb7f1aafb30b202870dc15b9d09e3ee8fe8131ffc26d521c1e56b5b030f39fba329143a32b2fa88351d57df3ae5aa29498384a251946
+  languageName: node
+  linkType: hard
+
 "@vitejs/plugin-vue@npm:4.0.0":
   version: 4.0.0
   resolution: "@vitejs/plugin-vue@npm:4.0.0"
@@ -15791,11 +15798,13 @@ __metadata:
   resolution: "sw@workspace:packages/sw"
   dependencies:
     "@typescript-eslint/parser": ^5.45.0
+    "@typescript/lib-webworker": "npm:@types/serviceworker@^0.0.58"
     esbuild: ^0.14.42
     eslint: ^8.16.0
     eslint-plugin-import: ^2.26.0
     idb-keyval: ^6.1.0
     misskey-js: 0.0.14
+    typescript: 4.9.4
   languageName: unknown
   linkType: soft