feat: add ESLint to the backend

backend/.prettierignore

@@ -1,3 +1,4 @@
 pnpm-lock.yaml
 *.generated.*
 db-data
+drizzle

backend/drizzle.config.ts

@@ -1,11 +1,15 @@
 import "dotenv/config";
 import { defineConfig } from "drizzle-kit";
 
+if (!process.env.DATABASE_URL) {
+  throw new Error("DATABASE_URL environment variable is not set.");
+}
+
 export default defineConfig({
   out: "./drizzle",
   schema: "./src/db/schema/index.ts",
   dialect: "postgresql",
   dbCredentials: {
-    url: process.env.DATABASE_URL!,
+    url: process.env.DATABASE_URL,
   },
 });

backend/eslint.config.ts

@@ -0,0 +1,32 @@
+import js from "@eslint/js";
+import globals from "globals";
+import tseslint from "typescript-eslint";
+import { defineConfig, globalIgnores } from "eslint/config";
+
+export default defineConfig([
+  globalIgnores(["**/dist/**", "**/*.generated.ts"]),
+  {
+    files: ["**/*.{js,mjs,cjs,ts,mts,cts}"],
+    plugins: { js },
+    extends: [
+      "js/recommended",
+      tseslint.configs.strictTypeChecked,
+      tseslint.configs.stylisticTypeChecked,
+    ],
+    rules: {
+      // We assume that special states such as NaN, Infinity, and -Infinity are handled before displaying the number.
+      "@typescript-eslint/restrict-template-expressions": [
+        "error",
+        {
+          allowNumber: true,
+        },
+      ],
+    },
+    languageOptions: {
+      globals: globals.node,
+      parserOptions: {
+        projectService: true,
+      },
+    },
+  },
+]);

backend/package.json

@@ -10,9 +10,10 @@
   "description": "",
   "main": "dist/index.js",
   "scripts": {
-    "prestart": "graphql-codegen",
     "typecheck": "tsc",
-    "dev": "pnpm prestart && tsx watch src/index.ts",
+    "lint": "eslint .",
+    "codegen": "graphql-codegen",
+    "dev": "pnpm codegen && tsx watch src/index.ts",
     "build": "esbuild src/index.ts --bundle --platform=node --format=esm --target=node24 --packages=external --outfile=dist/index.js",
     "start": "pnpm build && node dist/index.js",
     "db:init": "initdb -D db-data -U postgres -E UTF8 --auth=trust",
@@ -43,29 +44,33 @@
   "dependencies": {
     "@apollo/server": "^5.5.1",
     "@as-integrations/express5": "^1.1.2",
-    "@better-auth/drizzle-adapter": "^1.7.12",
+    "@better-auth/drizzle-adapter": "^1.7.18",
     "@graphql-tools/merge": "^9.2.8",
-    "better-auth": "^1.7.12",
+    "better-auth": "^1.7.18",
     "cors": "^2.8.6",
     "csv-parse": "^7.0.3",
     "dataloader": "^2.2.3",
     "dotenv": "^18.0.9",
     "drizzle-orm": "1.0.0-rc.4",
     "express": "^5.3.0",
-    "graphql": "^17.0.2",
+    "graphql": "^17.1.0",
     "pg": "^8.23.1"
   },
   "devDependencies": {
     "@eddeee888/gcg-typescript-resolver-files": "^0.19.0",
+    "@eslint/js": "^10.0.1",
     "@graphql-codegen/cli": "^7.4.6",
     "@types/cors": "^2.8.19",
     "@types/express": "^5.0.6",
-    "@types/node": "^26.6.5",
+    "@types/node": "^26.6.6",
     "@types/pg": "^8.23.1",
     "drizzle-kit": "1.0.0-rc.4",
     "esbuild": "0.28.2",
+    "eslint": "^10.14.0",
+    "globals": "^17.14.0",
     "prettier": "3.9.9",
     "tsx": "^4.23.15",
-    "typescript": "^7.0.2"
+    "typescript": "^6.0.3",
+    "typescript-eslint": "^8.72.1"
   }
 }