ESLint

+ Add in ESLint support, with TS and Svelte included.
~ Resolve typing issues in both countdown, and in the healthcheck endpoint

.prettierrc

@@ -3,6 +3,7 @@
   "singleQuote": false,
   "printWidth": 90,
   "plugins": ["prettier-plugin-svelte"],
+  "overrides": [{ "files": "*.svelte", "options": { "parser": "svelte" } }],
   "semi": true,
   "svelteSortOrder": "options-styles-scripts-markup",
   "svelteStrictMode": false,

eslint.config.js

@@ -0,0 +1,37 @@
+import globals from "globals";
+import js from "@eslint/js";
+import eslintConfigPrettier from "eslint-config-prettier";
+import tsEslint from "typescript-eslint";
+import eslintPluginSvelte from "eslint-plugin-svelte";
+import svelteParser from "svelte-eslint-parser";
+
+export default tsEslint.config(
+  js.configs.recommended,
+  ...tsEslint.configs.recommended,
+  ...eslintPluginSvelte.configs["flat/recommended"],
+  eslintConfigPrettier,
+  ...eslintPluginSvelte.configs["flat/prettier"],
+  {
+    files: ["**/*.svelte"],
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: "module",
+      globals: { ...globals.node, ...globals.browser },
+      parser: svelteParser,
+      parserOptions: {
+        parser: tsEslint.parser,
+        extraFileExtensions: [".svelte"],
+      },
+    },
+  },
+  {
+    ignores: [
+      "**/.svelte-kit",
+      "**/.vercel",
+      "**/.yarn",
+      "**/build",
+      "**/node_modules",
+      "**/package",
+    ],
+  },
+);

package.json

@@ -8,29 +8,32 @@
     "preview": "vite preview",
     "check": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json",
     "check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch",
-    "lint": "prettier --check . && eslint .",
+    "lint": "eslint './src/**/*.{js,ts,svelte}' --fix",
     "format": "prettier --write ."
   },
   "devDependencies": {
+    "@eslint/js": "^9.0.0",
     "@sveltejs/adapter-auto": "^3.2.0",
-    "@sveltejs/kit": "^2.5.5",
-    "@sveltejs/vite-plugin-svelte": "^3.0.2",
-    "@typescript-eslint/eslint-plugin": "^7.5.0",
-    "@typescript-eslint/parser": "^7.5.0",
+    "@sveltejs/kit": "^2.5.6",
+    "@sveltejs/vite-plugin-svelte": "^3.1.0",
     "autoprefixer": "^10.4.19",
     "daisyui": "latest",
     "eslint": "^9.0.0",
     "eslint-config-prettier": "^9.1.0",
-    "eslint-plugin-svelte": "^2.36.0",
+    "eslint-plugin-svelte": "^2.37.0",
+    "globals": "^15.0.0",
     "postcss": "^8.4.38",
     "prettier": "^3.2.5",
     "prettier-plugin-svelte": "^3.2.3",
-    "svelte": "^4.2.12",
+    "svelte": "^4.2.15",
     "svelte-check": "^3.6.9",
+    "svelte-eslint-parser": "^0.34.1",
+    "svelte-preprocess": "^5.1.4",
     "tailwindcss": "^3.4.3",
     "tslib": "^2.6.2",
-    "typescript": "^5.4.4",
-    "vite": "^5.2.8"
+    "typescript": "^5.4.5",
+    "typescript-eslint": "^7.7.0",
+    "vite": "^5.2.9"
   },
   "type": "module"
 }

src/components/countdown.svelte

@@ -2,7 +2,7 @@
   import { onMount } from "svelte";
 
   const GRADUATION = new Date(1753797600000).valueOf();
-  let interval: NodeJS.Timer;
+  let interval: ReturnType<typeof setInterval>;
 
   let timeTo = Math.abs(GRADUATION - Date.now().valueOf()) / 1000;
 

src/routes/api/healthcheck/+server.ts

@@ -1,5 +1,3 @@
-import type { RequestHandler } from "./$types";
-
-export const GET: RequestHandler = ({ url }) => {
+export function GET() {
   return new Response();
-};
+}

svelte.config.js

@@ -1,11 +1,11 @@
 import adapter from "@sveltejs/adapter-auto";
-import { vitePreprocess } from "@sveltejs/vite-plugin-svelte";
+import sveltePreprocess from "svelte-preprocess";
 
 /** @type {import('@sveltejs/kit').Config} */
 const config = {
   // Consult https://kit.svelte.dev/docs/integrations#preprocessors
   // for more information about preprocessors
-  preprocess: vitePreprocess(),
+  preprocess: sveltePreprocess(),
 
   kit: {
     // adapter-auto only supports some environments, see https://kit.svelte.dev/docs/adapter-auto for a list.