diff --git a/.eslintrc.js b/.eslintrc.js
index 22a307e..61bdf40 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -3,9 +3,12 @@ module.exports = {
         "browser": true,
         "es2021": true,
         "node": true,
-        "jest": true,
+        "jest/globals": true
     },
-    "extends": "airbnb-base",
+    "extends": [
+        "airbnb-base",
+        "plugin:jest/recommended"
+    ],
     "overrides": [
         {
             "env": {
@@ -24,5 +27,6 @@ module.exports = {
         "sourceType": "module"
     },
     "rules": {
-    }
-}
\ No newline at end of file
+    },
+    "plugins": ["jest"]
+};
diff --git a/__tests__/sum.test.js b/__tests__/sum.test.js
deleted file mode 100644
index eae1eed..0000000
--- a/__tests__/sum.test.js
+++ /dev/null
@@ -1,7 +0,0 @@
-// sum.test.js
-import { sum } from '../src/sum';
-
-test('adds 1 + 2 to equal 3', () => {
-  expect(sum(1, 2)).toBe(3);
-});
-
diff --git a/dockerfile b/dockerfile
index e69de29..54bfb2f 100644
--- a/dockerfile
+++ b/dockerfile
@@ -0,0 +1,18 @@
+# Use the official Node.js image.
+FROM node:14
+
+# Create and change to the app directory.
+WORKDIR /usr/src/app
+
+# Copy application dependency manifests to the container image.
+# A wildcard is used to ensure both package.json AND package-lock.json are copied.
+COPY package*.json ./
+
+# Install dependencies.
+RUN npm install --production
+
+# Copy local code to the container image.
+COPY . .
+
+# Run the web service on container startup.
+CMD [ "node", "index.js" ]
diff --git a/eslint-config.json b/eslint-config.json
new file mode 100644
index 0000000..e69de29
diff --git a/package-lock.json b/package-lock.json
index 7f42766..c10907b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21,7 +21,8 @@
         "@babel/preset-react": "^7.24.7",
         "@eslint/js": "^9.7.0",
         "babel-jest": "^29.7.0",
-        "eslint": "^9.7.0",
+        "eslint": "^8.57.0",
+        "eslint-plugin-jest": "^28.6.0",
         "globals": "^15.8.0",
         "jest": "^29.7.0"
       }
@@ -2218,57 +2219,17 @@
         "node": "^12.0.0 || ^14.0.0 || >=16.0.0"
       }
     },
-    "node_modules/@eslint/config-array": {
-      "version": "0.17.1",
-      "resolved": "https://registry.npmjs.org/@eslint/config-array/-/config-array-0.17.1.tgz",
-      "integrity": "sha512-BlYOpej8AQ8Ev9xVqroV7a02JK3SkBAaN9GfMMH9W6Ch8FlQlkjGw4Ir7+FgYwfirivAf4t+GtzuAxqfukmISA==",
-      "dev": true,
-      "license": "Apache-2.0",
-      "dependencies": {
-        "@eslint/object-schema": "^2.1.4",
-        "debug": "^4.3.1",
-        "minimatch": "^3.1.2"
-      },
-      "engines": {
-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
-      }
-    },
-    "node_modules/@eslint/config-array/node_modules/debug": {
-      "version": "4.3.5",
-      "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.5.tgz",
-      "integrity": "sha512-pt0bNEmneDIvdL1Xsd9oDQ/wrQRkXDT4AUWlNZNPKvW5x/jyO9VFXkJUP07vQ2upmw5PlaITaPKc31jK13V+jg==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "ms": "2.1.2"
-      },
-      "engines": {
-        "node": ">=6.0"
-      },
-      "peerDependenciesMeta": {
-        "supports-color": {
-          "optional": true
-        }
-      }
-    },
-    "node_modules/@eslint/config-array/node_modules/ms": {
-      "version": "2.1.2",
-      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
-      "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/@eslint/eslintrc": {
-      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/@eslint/eslintrc/-/eslintrc-3.1.0.tgz",
-      "integrity": "sha512-4Bfj15dVJdoy3RfZmmo86RK1Fwzn6SstsvK9JS+BaVKqC6QQQQyXekNaC+g+LKNgkQ+2VhGAzm6hO40AhMR3zQ==",
+      "version": "2.1.4",
+      "resolved": "https://registry.npmjs.org/@eslint/eslintrc/-/eslintrc-2.1.4.tgz",
+      "integrity": "sha512-269Z39MS6wVJtsoUl10L60WdkhJVdPG24Q4eZTH3nnF6lpvSShEK3wQjDX9JRWAUPvPh7COouPpU9IrqaZFvtQ==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
         "ajv": "^6.12.4",
         "debug": "^4.3.2",
-        "espree": "^10.0.1",
-        "globals": "^14.0.0",
+        "espree": "^9.6.0",
+        "globals": "^13.19.0",
         "ignore": "^5.2.0",
         "import-fresh": "^3.2.1",
         "js-yaml": "^4.1.0",
@@ -2276,7 +2237,7 @@
         "strip-json-comments": "^3.1.1"
       },
       "engines": {
-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
       },
       "funding": {
         "url": "https://opencollective.com/eslint"
@@ -2301,13 +2262,16 @@
       }
     },
     "node_modules/@eslint/eslintrc/node_modules/globals": {
-      "version": "14.0.0",
-      "resolved": "https://registry.npmjs.org/globals/-/globals-14.0.0.tgz",
-      "integrity": "sha512-oahGvuMGQlPw/ivIYBjVSrWAfWLBeku5tpPE2fOPLi+WHffIWbuh2tCjhyQhTBPMf5E9jDEH4FOmTYgYwbKwtQ==",
+      "version": "13.24.0",
+      "resolved": "https://registry.npmjs.org/globals/-/globals-13.24.0.tgz",
+      "integrity": "sha512-AhO5QUcj8llrbG09iWhPU2B204J1xnPeL8kQmVorSsy+Sjj1sk8gIyh6cUocGmH4L0UuhAJy+hJMRA4mgA4mFQ==",
       "dev": true,
       "license": "MIT",
+      "dependencies": {
+        "type-fest": "^0.20.2"
+      },
       "engines": {
-        "node": ">=18"
+        "node": ">=8"
       },
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
@@ -2320,6 +2284,19 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@eslint/eslintrc/node_modules/type-fest": {
+      "version": "0.20.2",
+      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-0.20.2.tgz",
+      "integrity": "sha512-Ne+eE4r0/iWnpAxD852z3A+N0Bt5RN//NjJwRd2VFHEmrywxf5vsZlh4R6lixl6B+wz/8d+maTSAkN1FIkI3LQ==",
+      "dev": true,
+      "license": "(MIT OR CC0-1.0)",
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/@eslint/js": {
       "version": "9.7.0",
       "resolved": "https://registry.npmjs.org/@eslint/js/-/js-9.7.0.tgz",
@@ -2330,16 +2307,47 @@
         "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
       }
     },
-    "node_modules/@eslint/object-schema": {
-      "version": "2.1.4",
-      "resolved": "https://registry.npmjs.org/@eslint/object-schema/-/object-schema-2.1.4.tgz",
-      "integrity": "sha512-BsWiH1yFGjXXS2yvrf5LyuoSIIbPrGUWob917o+BTKuZ7qJdxX8aJLRxs1fS9n6r7vESrq1OUqb68dANcFXuQQ==",
+    "node_modules/@humanwhocodes/config-array": {
+      "version": "0.11.14",
+      "resolved": "https://registry.npmjs.org/@humanwhocodes/config-array/-/config-array-0.11.14.tgz",
+      "integrity": "sha512-3T8LkOmg45BV5FICb15QQMsyUSWrQ8AygVfC7ZG32zOalnqrilm018ZVCw0eapXux8FtA33q8PSRSstjee3jSg==",
+      "deprecated": "Use @eslint/config-array instead",
       "dev": true,
       "license": "Apache-2.0",
+      "dependencies": {
+        "@humanwhocodes/object-schema": "^2.0.2",
+        "debug": "^4.3.1",
+        "minimatch": "^3.0.5"
+      },
       "engines": {
-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+        "node": ">=10.10.0"
       }
     },
+    "node_modules/@humanwhocodes/config-array/node_modules/debug": {
+      "version": "4.3.5",
+      "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.5.tgz",
+      "integrity": "sha512-pt0bNEmneDIvdL1Xsd9oDQ/wrQRkXDT4AUWlNZNPKvW5x/jyO9VFXkJUP07vQ2upmw5PlaITaPKc31jK13V+jg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "ms": "2.1.2"
+      },
+      "engines": {
+        "node": ">=6.0"
+      },
+      "peerDependenciesMeta": {
+        "supports-color": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@humanwhocodes/config-array/node_modules/ms": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+      "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@humanwhocodes/module-importer": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/@humanwhocodes/module-importer/-/module-importer-1.0.1.tgz",
@@ -2354,19 +2362,13 @@
         "url": "https://github.com/sponsors/nzakas"
       }
     },
-    "node_modules/@humanwhocodes/retry": {
-      "version": "0.3.0",
-      "resolved": "https://registry.npmjs.org/@humanwhocodes/retry/-/retry-0.3.0.tgz",
-      "integrity": "sha512-d2CGZR2o7fS6sWB7DG/3a95bGKQyHMACZ5aW8qGkkqQpUoZV6C0X7Pc7l4ZNMZkfNBf4VWNe9E1jRsf0G146Ew==",
+    "node_modules/@humanwhocodes/object-schema": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/@humanwhocodes/object-schema/-/object-schema-2.0.3.tgz",
+      "integrity": "sha512-93zYdMES/c1D69yZiKDBj0V24vqNzB/koF26KPaagAfd3P/4gUlh3Dys5ogAK+Exi9QyzlD8x/08Zt7wIKcDcA==",
+      "deprecated": "Use @eslint/object-schema instead",
       "dev": true,
-      "license": "Apache-2.0",
-      "engines": {
-        "node": ">=18.18"
-      },
-      "funding": {
-        "type": "github",
-        "url": "https://github.com/sponsors/nzakas"
-      }
+      "license": "BSD-3-Clause"
     },
     "node_modules/@istanbuljs/load-nyc-config": {
       "version": "1.1.0",
@@ -3032,6 +3034,143 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@typescript-eslint/scope-manager": {
+      "version": "7.17.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/scope-manager/-/scope-manager-7.17.0.tgz",
+      "integrity": "sha512-0P2jTTqyxWp9HiKLu/Vemr2Rg1Xb5B7uHItdVZ6iAenXmPo4SZ86yOPCJwMqpCyaMiEHTNqizHfsbmCFT1x9SA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@typescript-eslint/types": "7.17.0",
+        "@typescript-eslint/visitor-keys": "7.17.0"
+      },
+      "engines": {
+        "node": "^18.18.0 || >=20.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      }
+    },
+    "node_modules/@typescript-eslint/types": {
+      "version": "7.17.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/types/-/types-7.17.0.tgz",
+      "integrity": "sha512-a29Ir0EbyKTKHnZWbNsrc/gqfIBqYPwj3F2M+jWE/9bqfEHg0AMtXzkbUkOG6QgEScxh2+Pz9OXe11jHDnHR7A==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": "^18.18.0 || >=20.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      }
+    },
+    "node_modules/@typescript-eslint/typescript-estree": {
+      "version": "7.17.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/typescript-estree/-/typescript-estree-7.17.0.tgz",
+      "integrity": "sha512-72I3TGq93t2GoSBWI093wmKo0n6/b7O4j9o8U+f65TVD0FS6bI2180X5eGEr8MA8PhKMvYe9myZJquUT2JkCZw==",
+      "dev": true,
+      "license": "BSD-2-Clause",
+      "dependencies": {
+        "@typescript-eslint/types": "7.17.0",
+        "@typescript-eslint/visitor-keys": "7.17.0",
+        "debug": "^4.3.4",
+        "globby": "^11.1.0",
+        "is-glob": "^4.0.3",
+        "minimatch": "^9.0.4",
+        "semver": "^7.6.0",
+        "ts-api-utils": "^1.3.0"
+      },
+      "engines": {
+        "node": "^18.18.0 || >=20.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      },
+      "peerDependenciesMeta": {
+        "typescript": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@typescript-eslint/typescript-estree/node_modules/brace-expansion": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.0.1.tgz",
+      "integrity": "sha512-XnAIvQ8eM+kC6aULx6wuQiwVsnzsi9d3WxzV3FpWTGA19F621kwdbsAcFKXgKUHZWsy+mY6iL1sHTxWEFCytDA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "balanced-match": "^1.0.0"
+      }
+    },
+    "node_modules/@typescript-eslint/typescript-estree/node_modules/debug": {
+      "version": "4.3.5",
+      "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.5.tgz",
+      "integrity": "sha512-pt0bNEmneDIvdL1Xsd9oDQ/wrQRkXDT4AUWlNZNPKvW5x/jyO9VFXkJUP07vQ2upmw5PlaITaPKc31jK13V+jg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "ms": "2.1.2"
+      },
+      "engines": {
+        "node": ">=6.0"
+      },
+      "peerDependenciesMeta": {
+        "supports-color": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@typescript-eslint/typescript-estree/node_modules/minimatch": {
+      "version": "9.0.5",
+      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-9.0.5.tgz",
+      "integrity": "sha512-G6T0ZX48xgozx7587koeX9Ys2NYy6Gmv//P89sEte9V9whIapMNF4idKxnW2QtCcLiTWlb/wfCabAtAFWhhBow==",
+      "dev": true,
+      "license": "ISC",
+      "dependencies": {
+        "brace-expansion": "^2.0.1"
+      },
+      "engines": {
+        "node": ">=16 || 14 >=14.17"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
+    "node_modules/@typescript-eslint/typescript-estree/node_modules/ms": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+      "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/@typescript-eslint/visitor-keys": {
+      "version": "7.17.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/visitor-keys/-/visitor-keys-7.17.0.tgz",
+      "integrity": "sha512-RVGC9UhPOCsfCdI9pU++K4nD7to+jTcMIbXTSOcrLqUEW6gF2pU1UUbYJKc9cvcRSK1UDeMJ7pdMxf4bhMpV/A==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@typescript-eslint/types": "7.17.0",
+        "eslint-visitor-keys": "^3.4.3"
+      },
+      "engines": {
+        "node": "^18.18.0 || >=20.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      }
+    },
+    "node_modules/@ungap/structured-clone": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/@ungap/structured-clone/-/structured-clone-1.2.0.tgz",
+      "integrity": "sha512-zuVdFrMJiuCDQUMCzQaD6KL28MjnqqN8XnAqiEq9PNm/hCPTSGfrXCOfwj1ow4LFb/tNymJPwsNbVePc1xFqrQ==",
+      "dev": true,
+      "license": "ISC"
+    },
     "node_modules/accepts": {
       "version": "1.3.8",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.8.tgz",
@@ -3152,6 +3291,16 @@
       "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
       "integrity": "sha512-PCVAQswWemu6UdxsDFFX/+gVeYqKAod3D3UVm91jHwynguOwAvYPhx8nNlM++NqRcK6CxxpUafjmhIdKiHibqg=="
     },
+    "node_modules/array-union": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/array-union/-/array-union-2.1.0.tgz",
+      "integrity": "sha512-HGyxoOTYUyCM6stUe6EJgnd4EoewAI7zMdfqO+kGjnlZmBDz/cR5pf8r/cR4Wq60sL/p0IkcjUEEPwS3GFrIyw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/babel-jest": {
       "version": "29.7.0",
       "resolved": "https://registry.npmjs.org/babel-jest/-/babel-jest-29.7.0.tgz",
@@ -3809,6 +3958,32 @@
         "node": "^14.15.0 || ^16.10.0 || >=18.0.0"
       }
     },
+    "node_modules/dir-glob": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/dir-glob/-/dir-glob-3.0.1.tgz",
+      "integrity": "sha512-WkrWp9GR4KXfKGYzOLmTuGVi1UWFfws377n9cc55/tb6DuqyF6pcQ5AbiHEshaDpY9v6oaSr2XCDidGmMwdzIA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "path-type": "^4.0.0"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
+    "node_modules/doctrine": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/doctrine/-/doctrine-3.0.0.tgz",
+      "integrity": "sha512-yS+Q5i3hBf7GBkd4KG8a7eBNNWNGLTaEwwYWUijIYM7zrlYDM0BFXHjjPWlWZ1Rg7UaddZeIDmi9jF3HmqiQ2w==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "esutils": "^2.0.2"
+      },
+      "engines": {
+        "node": ">=6.0.0"
+      }
+    },
     "node_modules/dotenv": {
       "version": "16.4.5",
       "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-16.4.5.tgz",
@@ -3927,38 +4102,42 @@
       }
     },
     "node_modules/eslint": {
-      "version": "9.7.0",
-      "resolved": "https://registry.npmjs.org/eslint/-/eslint-9.7.0.tgz",
-      "integrity": "sha512-FzJ9D/0nGiCGBf8UXO/IGLTgLVzIxze1zpfA8Ton2mjLovXdAPlYDv+MQDcqj3TmrhAGYfOpz9RfR+ent0AgAw==",
+      "version": "8.57.0",
+      "resolved": "https://registry.npmjs.org/eslint/-/eslint-8.57.0.tgz",
+      "integrity": "sha512-dZ6+mexnaTIbSBZWgou51U6OmzIhYM2VcNdtiTtI7qPNZm35Akpr0f6vtw3w1Kmn5PYo+tZVfh13WrhpS6oLqQ==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
         "@eslint-community/eslint-utils": "^4.2.0",
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-        "@eslint/eslintrc": "^3.1.0",
-        "@eslint/js": "9.7.0",
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-        "@humanwhocodes/retry": "^0.3.0",
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         "ajv": "^6.12.4",
         "chalk": "^4.0.0",
         "cross-spawn": "^7.0.2",
         "debug": "^4.3.2",
+        "doctrine": "^3.0.0",
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-        "eslint-visitor-keys": "^4.0.0",
-        "espree": "^10.1.0",
-        "esquery": "^1.5.0",
+        "eslint-scope": "^7.2.2",
+        "eslint-visitor-keys": "^3.4.3",
+        "espree": "^9.6.1",
+        "esquery": "^1.4.2",
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         "fast-deep-equal": "^3.1.3",
-        "file-entry-cache": "^8.0.0",
+        "file-entry-cache": "^6.0.1",
         "find-up": "^5.0.0",
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+        "globals": "^13.19.0",
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         "imurmurhash": "^0.1.4",
         "is-glob": "^4.0.0",
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         "levn": "^0.4.1",
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         "eslint": "bin/eslint.js"
       },
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-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
+      },
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+        "url": "https://opencollective.com/eslint"
+      }
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+      "resolved": "https://registry.npmjs.org/eslint-plugin-jest/-/eslint-plugin-jest-28.6.0.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@typescript-eslint/utils": "^6.0.0 || ^7.0.0"
+      },
+      "engines": {
+        "node": "^16.10.0 || ^18.12.0 || >=20.0.0"
+      },
+      "peerDependencies": {
+        "@typescript-eslint/eslint-plugin": "^6.0.0 || ^7.0.0",
+        "eslint": "^7.0.0 || ^8.0.0 || ^9.0.0",
+        "jest": "*"
+      },
+      "peerDependenciesMeta": {
+        "@typescript-eslint/eslint-plugin": {
+          "optional": true
+        },
+        "jest": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/eslint-plugin-jest/node_modules/@typescript-eslint/utils": {
+      "version": "7.17.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/utils/-/utils-7.17.0.tgz",
+      "integrity": "sha512-r+JFlm5NdB+JXc7aWWZ3fKSm1gn0pkswEwIYsrGPdsT2GjsRATAKXiNtp3vgAAO1xZhX8alIOEQnNMl3kbTgJw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@eslint-community/eslint-utils": "^4.4.0",
+        "@typescript-eslint/scope-manager": "7.17.0",
+        "@typescript-eslint/types": "7.17.0",
+        "@typescript-eslint/typescript-estree": "7.17.0"
+      },
+      "engines": {
+        "node": "^18.18.0 || >=20.0.0"
       },
       "funding": {
-        "url": "https://eslint.org/donate"
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      },
+      "peerDependencies": {
+        "eslint": "^8.56.0"
       }
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-      "version": "8.0.2",
-      "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-8.0.2.tgz",
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+      "version": "7.2.2",
+      "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-7.2.2.tgz",
+      "integrity": "sha512-dOt21O7lTMhDM+X9mB4GX+DZrZtCUJPL/wlcTqxyrx5IvO0IYtILdtrQGQp+8n5S0gwSVmOf9NQrjMOgfQZlIg==",
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@@ -3989,7 +4217,7 @@
         "estraverse": "^5.2.0"
       },
       "engines": {
-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
       },
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         "url": "https://opencollective.com/eslint"
@@ -4008,6 +4236,16 @@
         "url": "https://opencollective.com/eslint"
       }
     },
+    "node_modules/eslint/node_modules/@eslint/js": {
+      "version": "8.57.0",
+      "resolved": "https://registry.npmjs.org/@eslint/js/-/js-8.57.0.tgz",
+      "integrity": "sha512-Ys+3g2TaW7gADOJzPt83SJtCDhMjndcDMFVQ/Tj9iA1BfJzFKD9mAUXT3OenpuPHbI6P/myECxRJrofUsDx/5g==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
+      }
+    },
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       "version": "4.3.5",
       "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.5.tgz",
@@ -4026,17 +4264,20 @@
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-      "resolved": "https://registry.npmjs.org/eslint-visitor-keys/-/eslint-visitor-keys-4.0.0.tgz",
-      "integrity": "sha512-OtIRv/2GyiF6o/d8K7MYKKbXrOUBIK6SfkIRM4Z0dY3w+LiQ0vy3F57m0Z71bjbyeiWFiHJ8brqnmE6H6/jEuw==",
+    "node_modules/eslint/node_modules/globals": {
+      "version": "13.24.0",
+      "resolved": "https://registry.npmjs.org/globals/-/globals-13.24.0.tgz",
+      "integrity": "sha512-AhO5QUcj8llrbG09iWhPU2B204J1xnPeL8kQmVorSsy+Sjj1sk8gIyh6cUocGmH4L0UuhAJy+hJMRA4mgA4mFQ==",
       "dev": true,
-      "license": "Apache-2.0",
+      "license": "MIT",
+      "dependencies": {
+        "type-fest": "^0.20.2"
+      },
       "engines": {
-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+        "node": ">=8"
       },
       "funding": {
-        "url": "https://opencollective.com/eslint"
+        "url": "https://github.com/sponsors/sindresorhus"
       }
     },
     "node_modules/eslint/node_modules/ms": {
@@ -4046,32 +4287,32 @@
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       "license": "MIT"
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-    "node_modules/espree": {
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-      "resolved": "https://registry.npmjs.org/espree/-/espree-10.1.0.tgz",
-      "integrity": "sha512-M1M6CpiE6ffoigIOWYO9UDP8TMUw9kqb21tf+08IgDYjCsOvCuDt4jQcZmoYxx+w7zlKw9/N0KXfto+I8/FrXA==",
+    "node_modules/eslint/node_modules/type-fest": {
+      "version": "0.20.2",
+      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-0.20.2.tgz",
+      "integrity": "sha512-Ne+eE4r0/iWnpAxD852z3A+N0Bt5RN//NjJwRd2VFHEmrywxf5vsZlh4R6lixl6B+wz/8d+maTSAkN1FIkI3LQ==",
       "dev": true,
-      "license": "BSD-2-Clause",
-      "dependencies": {
-        "acorn": "^8.12.0",
-        "acorn-jsx": "^5.3.2",
-        "eslint-visitor-keys": "^4.0.0"
-      },
+      "license": "(MIT OR CC0-1.0)",
       "engines": {
-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+        "node": ">=10"
       },
       "funding": {
-        "url": "https://opencollective.com/eslint"
+        "url": "https://github.com/sponsors/sindresorhus"
       }
     },
-    "node_modules/espree/node_modules/eslint-visitor-keys": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/eslint-visitor-keys/-/eslint-visitor-keys-4.0.0.tgz",
-      "integrity": "sha512-OtIRv/2GyiF6o/d8K7MYKKbXrOUBIK6SfkIRM4Z0dY3w+LiQ0vy3F57m0Z71bjbyeiWFiHJ8brqnmE6H6/jEuw==",
+    "node_modules/espree": {
+      "version": "9.6.1",
+      "resolved": "https://registry.npmjs.org/espree/-/espree-9.6.1.tgz",
+      "integrity": "sha512-oruZaFkjorTpF32kDSI5/75ViwGeZginGGy2NoOSg3Q9bnwlnmDm4HLnkl0RE3n+njDXR037aY1+x58Z/zFdwQ==",
       "dev": true,
-      "license": "Apache-2.0",
+      "license": "BSD-2-Clause",
+      "dependencies": {
+        "acorn": "^8.9.0",
+        "acorn-jsx": "^5.3.2",
+        "eslint-visitor-keys": "^3.4.1"
+      },
       "engines": {
-        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
       },
       "funding": {
         "url": "https://opencollective.com/eslint"
@@ -4243,6 +4484,36 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/fast-glob": {
+      "version": "3.3.2",
+      "resolved": "https://registry.npmjs.org/fast-glob/-/fast-glob-3.3.2.tgz",
+      "integrity": "sha512-oX2ruAFQwf/Orj8m737Y5adxDQO0LAB7/S5MnxCdTNDd4p6BsyIVsv9JQsATbTSq8KHRpLwIHbVlUNatxd+1Ow==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@nodelib/fs.stat": "^2.0.2",
+        "@nodelib/fs.walk": "^1.2.3",
+        "glob-parent": "^5.1.2",
+        "merge2": "^1.3.0",
+        "micromatch": "^4.0.4"
+      },
+      "engines": {
+        "node": ">=8.6.0"
+      }
+    },
+    "node_modules/fast-glob/node_modules/glob-parent": {
+      "version": "5.1.2",
+      "resolved": "https://registry.npmjs.org/glob-parent/-/glob-parent-5.1.2.tgz",
+      "integrity": "sha512-AOIgSQCepiJYwP3ARnGx+5VnTu2HBYdzbGP45eLw1vr3zB3vZLeyed1sC9hnbcOc9/SrMyM5RPQrkGz4aS9Zow==",
+      "dev": true,
+      "license": "ISC",
+      "dependencies": {
+        "is-glob": "^4.0.1"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
     "node_modules/fast-json-stable-stringify": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.1.0.tgz",
@@ -4278,16 +4549,16 @@
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     "node_modules/file-entry-cache": {
-      "version": "8.0.0",
-      "resolved": "https://registry.npmjs.org/file-entry-cache/-/file-entry-cache-8.0.0.tgz",
-      "integrity": "sha512-XXTUwCvisa5oacNGRP9SfNtYBNAMi+RPwBFmblZEF7N7swHYQS6/Zfk7SRwx4D5j3CH211YNRco1DEMNVfZCnQ==",
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/file-entry-cache/-/file-entry-cache-6.0.1.tgz",
+      "integrity": "sha512-7Gps/XWymbLk2QLYK4NzpMOrYjMhdIxXuIvy2QBsLE6ljuodKvdkWs/cpyJJ3CVIVpH0Oi1Hvg1ovbMzLdFBBg==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "flat-cache": "^4.0.0"
+        "flat-cache": "^3.0.4"
       },
       "engines": {
-        "node": ">=16.0.0"
+        "node": "^10.12.0 || >=12.0.0"
       }
     },
     "node_modules/fill-range": {
@@ -4338,17 +4609,18 @@
       }
     },
     "node_modules/flat-cache": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/flat-cache/-/flat-cache-4.0.1.tgz",
-      "integrity": "sha512-f7ccFPK3SXFHpx15UIGyRJ/FJQctuKZ0zVuN3frBo4HnK3cay9VEW0R6yPYFHC0AgqhukPzKjq22t5DmAyqGyw==",
+      "version": "3.2.0",
+      "resolved": "https://registry.npmjs.org/flat-cache/-/flat-cache-3.2.0.tgz",
+      "integrity": "sha512-CYcENa+FtcUKLmhhqyctpclsq7QF38pKjZHsGNiSQF5r4FtoKDWabFDl3hzaEQMvT1LHEysw5twgLvpYYb4vbw==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
         "flatted": "^3.2.9",
-        "keyv": "^4.5.4"
+        "keyv": "^4.5.3",
+        "rimraf": "^3.0.2"
       },
       "engines": {
-        "node": ">=16"
+        "node": "^10.12.0 || >=12.0.0"
       }
     },
     "node_modules/flatted": {
@@ -4513,6 +4785,27 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/globby": {
+      "version": "11.1.0",
+      "resolved": "https://registry.npmjs.org/globby/-/globby-11.1.0.tgz",
+      "integrity": "sha512-jhIXaOzy1sb8IyocaruWSn1TjmnBVs8Ayhcy83rmxNJ8q2uWKCAj3CnJY+KpGSXCueAPc0i05kVvVKtP1t9S3g==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "array-union": "^2.1.0",
+        "dir-glob": "^3.0.1",
+        "fast-glob": "^3.2.9",
+        "ignore": "^5.2.0",
+        "merge2": "^1.4.1",
+        "slash": "^3.0.0"
+      },
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/gopd": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.0.1.tgz",
@@ -4531,6 +4824,13 @@
       "dev": true,
       "license": "ISC"
     },
+    "node_modules/graphemer": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/graphemer/-/graphemer-1.4.0.tgz",
+      "integrity": "sha512-EtKwoO6kxCL9WO5xipiHTZlSzBm7WLT627TqC/uVRd0HKmq8NXyebnNYxDoBi7wt8eTWrUrKXCOVaFq9x1kgag==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/has-flag": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-4.0.0.tgz",
@@ -5799,6 +6099,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/merge2": {
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/merge2/-/merge2-1.4.1.tgz",
+      "integrity": "sha512-8q7VEgMJW4J8tcfVPy8g09NcQwZdbwFEqhe/WZkoIzjn/3TGDwtOCYtXGxA3O8tPzpczCCDgv+P2P5y00ZJOOg==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">= 8"
+      }
+    },
     "node_modules/methods": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/methods/-/methods-1.1.2.tgz",
@@ -6241,6 +6551,16 @@
       "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-0.1.7.tgz",
       "integrity": "sha512-5DFkuoqlv1uYQKxy8omFBeJPQcdoE07Kv2sferDCrAq1ohOU+MSDswDIbnx3YAM60qIOnYa53wBhXW0EbMonrQ=="
     },
+    "node_modules/path-type": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/path-type/-/path-type-4.0.0.tgz",
+      "integrity": "sha512-gDKb8aZMDeD/tZWs9P6+q0J9Mwkdl6xMV8TjnGP3qJVJ06bdMgkbBlLU8IdfOsIsFz2BW1rNVT3XuNEl8zPAvw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/picocolors": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.0.1.tgz",
@@ -6652,6 +6972,23 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/rimraf": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/rimraf/-/rimraf-3.0.2.tgz",
+      "integrity": "sha512-JZkJMZkAGFFPP2YqXZXPbMlMBgsxzE8ILs4lMIX/2o0L9UBw9O/Y3o6wFw/i9YLapcUJWwqbi3kdxIPdC62TIA==",
+      "deprecated": "Rimraf versions prior to v4 are no longer supported",
+      "dev": true,
+      "license": "ISC",
+      "dependencies": {
+        "glob": "^7.1.3"
+      },
+      "bin": {
+        "rimraf": "bin.js"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
     "node_modules/run-parallel": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/run-parallel/-/run-parallel-1.2.0.tgz",
@@ -7082,6 +7419,19 @@
         "node": ">=14"
       }
     },
+    "node_modules/ts-api-utils": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/ts-api-utils/-/ts-api-utils-1.3.0.tgz",
+      "integrity": "sha512-UQMIo7pb8WRomKR1/+MFVLTroIvDVtMX3K6OUir8ynLyzB8Jeriont2bTAtmNPa1ekAgN7YPDyf6V+ygrdU+eQ==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=16"
+      },
+      "peerDependencies": {
+        "typescript": ">=4.2.0"
+      }
+    },
     "node_modules/type-check": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.4.0.tgz",
@@ -7130,6 +7480,21 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/typescript": {
+      "version": "5.5.4",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.4.tgz",
+      "integrity": "sha512-Mtq29sKDAEYP7aljRgtPOpTvOfbwRWlS6dPRzwjdE+C0R4brX/GUyhHSecbHMFLNBLcJIPt9nl9yG5TZ1weH+Q==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "peer": true,
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    },
     "node_modules/undici-types": {
       "version": "5.26.5",
       "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",
diff --git a/package.json b/package.json
index 23a16c8..14b78cd 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,8 @@
     "@babel/preset-react": "^7.24.7",
     "@eslint/js": "^9.7.0",
     "babel-jest": "^29.7.0",
-    "eslint": "^9.7.0",
+    "eslint": "^8.57.0",
+    "eslint-plugin-jest": "^28.6.0",
     "globals": "^15.8.0",
     "jest": "^29.7.0"
   }
diff --git a/server.js b/server.js
index e69de29..2df8f23 100644
--- a/server.js
+++ b/server.js
@@ -0,0 +1,34 @@
+const express = require('express');
+const mongoose = require('mongoose');
+const authRoutes = require('./routes/auth');
+const postRoutes = require('./routes/posts');
+require('dotenv').config();
+
+
+const app = express();
+const port = process.env.PORT || 3000;
+
+app.use(express.json());
+
+// MongoDB connection
+mongoose.connect('mongodb://localhost:27017/blogging', {
+  useNewUrlParser: true,
+  useUnifiedTopology: true,
+});
+
+const db = mongoose.connection;
+db.on('error', console.error.bind(console, 'connection error:'));
+db.once('open', () => {
+  console.log('Connected to MongoDB');
+});
+
+app.get('/', (req, res) => {
+  res.send('Hello, world!');
+});
+
+app.use('/auth', authRoutes);
+app.use('/posts', postRoutes);
+
+app.listen(port, () => {
+  console.log(`Server is running on port ${port}`);
+});
diff --git a/src/multiply.js b/src/multiply.js
new file mode 100644
index 0000000..c28519a
--- /dev/null
+++ b/src/multiply.js
@@ -0,0 +1,2 @@
+export const multiply = (a, b) => a * b;
+
diff --git a/src/sum.js b/src/sum.js
deleted file mode 100644
index 39d897e..0000000
--- a/src/sum.js
+++ /dev/null
@@ -1,2 +0,0 @@
-// sum.js
-export const sum = (a, b) => a + b;
diff --git a/tests/multiply.test.js b/tests/multiply.test.js
new file mode 100644
index 0000000..81a206f
--- /dev/null
+++ b/tests/multiply.test.js
@@ -0,0 +1,20 @@
+import { multiply } from '../src/multiply';
+
+// Simple test cases
+const testCases = [
+  { a: 2, b: 3, expected: 6 },
+  { a: 0, b: 3, expected: 0 },
+  { a: -1, b: 3, expected: -3 },
+];
+
+testCases.forEach(({ a, b, expected }) => {
+  const result = multiply(a, b);
+  if (result === expected) {
+    console.log(`Test passed for multiply(${a}, ${b}): ${result} === ${expected}`);
+  } else {
+    console.error(`Test failed for multiply(${a}, ${b}): ${result} !== ${expected}`);
+  }
+});
+
+
+