backend service structure, config, DB connection

service/.eslintrc.js

@@ -18,5 +18,7 @@ module.exports = {
     jest: true,
   },
   ignorePatterns: ['.eslintrc.js'],
-  rules: {},
+  rules: {
+    "@typescript-eslint/restrict-template-expressions": ["error", { "allowNumber": true, "allowNever": true }]
+  },
 };

service/package-lock.json

@@ -10,8 +10,13 @@
       "license": "UNLICENSED",
       "dependencies": {
         "@nestjs/common": "^10.0.0",
+        "@nestjs/config": "^3.3.0",
         "@nestjs/core": "^10.0.0",
         "@nestjs/platform-express": "^10.0.0",
+        "@nestjs/swagger": "^8.1.1",
+        "class-transformer": "^0.5.1",
+        "class-validator": "^0.14.1",
+        "pg": "^8.13.1",
         "reflect-metadata": "^0.2.0",
         "rxjs": "^7.8.1"
       },
@@ -23,6 +28,7 @@
         "@types/express": "^5.0.0",
         "@types/jest": "^29.5.2",
         "@types/node": "^20.3.1",
+        "@types/pg": "^8.11.10",
         "@types/supertest": "^6.0.0",
         "@typescript-eslint/eslint-plugin": "^8.0.0",
         "@typescript-eslint/parser": "^8.0.0",
@@ -1562,6 +1568,12 @@
         "node": ">=8"
       }
     },
+    "node_modules/@microsoft/tsdoc": {
+      "version": "0.15.1",
+      "resolved": "https://registry.npmjs.org/@microsoft/tsdoc/-/tsdoc-0.15.1.tgz",
+      "integrity": "sha512-4aErSrCR/On/e5G2hDP0wjooqDdauzEbIq8hIkIe5pXV0rtWJZvdCEKL0ykZxex+IxIwBp0eGeV48hQN07dXtw==",
+      "license": "MIT"
+    },
     "node_modules/@nestjs/cli": {
       "version": "10.4.9",
       "resolved": "https://registry.npmjs.org/@nestjs/cli/-/cli-10.4.9.tgz",
@@ -1651,6 +1663,21 @@
         }
       }
     },
+    "node_modules/@nestjs/config": {
+      "version": "3.3.0",
+      "resolved": "https://registry.npmjs.org/@nestjs/config/-/config-3.3.0.tgz",
+      "integrity": "sha512-pdGTp8m9d0ZCrjTpjkUbZx6gyf2IKf+7zlkrPNMsJzYZ4bFRRTpXrnj+556/5uiI6AfL5mMrJc2u7dB6bvM+VA==",
+      "license": "MIT",
+      "dependencies": {
+        "dotenv": "16.4.5",
+        "dotenv-expand": "10.0.0",
+        "lodash": "4.17.21"
+      },
+      "peerDependencies": {
+        "@nestjs/common": "^8.0.0 || ^9.0.0 || ^10.0.0",
+        "rxjs": "^7.1.0"
+      }
+    },
     "node_modules/@nestjs/core": {
       "version": "10.4.15",
       "resolved": "https://registry.npmjs.org/@nestjs/core/-/core-10.4.15.tgz",
@@ -1689,6 +1716,26 @@
         }
       }
     },
+    "node_modules/@nestjs/mapped-types": {
+      "version": "2.0.6",
+      "resolved": "https://registry.npmjs.org/@nestjs/mapped-types/-/mapped-types-2.0.6.tgz",
+      "integrity": "sha512-84ze+CPfp1OWdpRi1/lOu59hOhTz38eVzJvRKrg9ykRFwDz+XleKfMsG0gUqNZYFa6v53XYzeD+xItt8uDW7NQ==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@nestjs/common": "^8.0.0 || ^9.0.0 || ^10.0.0",
+        "class-transformer": "^0.4.0 || ^0.5.0",
+        "class-validator": "^0.13.0 || ^0.14.0",
+        "reflect-metadata": "^0.1.12 || ^0.2.0"
+      },
+      "peerDependenciesMeta": {
+        "class-transformer": {
+          "optional": true
+        },
+        "class-validator": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/@nestjs/platform-express": {
       "version": "10.4.15",
       "resolved": "https://registry.npmjs.org/@nestjs/platform-express/-/platform-express-10.4.15.tgz",
@@ -1734,6 +1781,39 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@nestjs/swagger": {
+      "version": "8.1.1",
+      "resolved": "https://registry.npmjs.org/@nestjs/swagger/-/swagger-8.1.1.tgz",
+      "integrity": "sha512-5Mda7H1DKnhKtlsb0C7PYshcvILv8UFyUotHzxmWh0G65Z21R3LZH/J8wmpnlzL4bmXIfr42YwbEwRxgzpJ5sQ==",
+      "license": "MIT",
+      "dependencies": {
+        "@microsoft/tsdoc": "^0.15.0",
+        "@nestjs/mapped-types": "2.0.6",
+        "js-yaml": "4.1.0",
+        "lodash": "4.17.21",
+        "path-to-regexp": "3.3.0",
+        "swagger-ui-dist": "5.18.2"
+      },
+      "peerDependencies": {
+        "@fastify/static": "^6.0.0 || ^7.0.0",
+        "@nestjs/common": "^9.0.0 || ^10.0.0",
+        "@nestjs/core": "^9.0.0 || ^10.0.0",
+        "class-transformer": "*",
+        "class-validator": "*",
+        "reflect-metadata": "^0.1.12 || ^0.2.0"
+      },
+      "peerDependenciesMeta": {
+        "@fastify/static": {
+          "optional": true
+        },
+        "class-transformer": {
+          "optional": true
+        },
+        "class-validator": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/@nestjs/testing": {
       "version": "10.4.15",
       "resolved": "https://registry.npmjs.org/@nestjs/testing/-/testing-10.4.15.tgz",
@@ -1842,6 +1922,13 @@
         "url": "https://opencollective.com/unts"
       }
     },
+    "node_modules/@scarf/scarf": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/@scarf/scarf/-/scarf-1.4.0.tgz",
+      "integrity": "sha512-xxeapPiUXdZAE3che6f3xogoJPeZgig6omHEy1rIY5WVsB3H2BHNnZH+gHG6x91SCWyQCzWGsuL2Hh3ClO5/qQ==",
+      "hasInstallScript": true,
+      "license": "Apache-2.0"
+    },
     "node_modules/@sinclair/typebox": {
       "version": "0.27.8",
       "resolved": "https://registry.npmjs.org/@sinclair/typebox/-/typebox-0.27.8.tgz",
@@ -2118,6 +2205,80 @@
         "undici-types": "~6.19.2"
       }
     },
+    "node_modules/@types/pg": {
+      "version": "8.11.10",
+      "resolved": "https://registry.npmjs.org/@types/pg/-/pg-8.11.10.tgz",
+      "integrity": "sha512-LczQUW4dbOQzsH2RQ5qoeJ6qJPdrcM/DcMLoqWQkMLMsq83J5lAX3LXjdkWdpscFy67JSOWDnh7Ny/sPFykmkg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*",
+        "pg-protocol": "*",
+        "pg-types": "^4.0.1"
+      }
+    },
+    "node_modules/@types/pg/node_modules/pg-types": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/pg-types/-/pg-types-4.0.2.tgz",
+      "integrity": "sha512-cRL3JpS3lKMGsKaWndugWQoLOCoP+Cic8oseVcbr0qhPzYD5DWXK+RZ9LY9wxRf7RQia4SCwQlXk0q6FCPrVng==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "pg-int8": "1.0.1",
+        "pg-numeric": "1.0.2",
+        "postgres-array": "~3.0.1",
+        "postgres-bytea": "~3.0.0",
+        "postgres-date": "~2.1.0",
+        "postgres-interval": "^3.0.0",
+        "postgres-range": "^1.1.1"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
+    "node_modules/@types/pg/node_modules/postgres-array": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/postgres-array/-/postgres-array-3.0.2.tgz",
+      "integrity": "sha512-6faShkdFugNQCLwucjPcY5ARoW1SlbnrZjmGl0IrrqewpvxvhSLHimCVzqeuULCbG0fQv7Dtk1yDbG3xv7Veog==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/@types/pg/node_modules/postgres-bytea": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/postgres-bytea/-/postgres-bytea-3.0.0.tgz",
+      "integrity": "sha512-CNd4jim9RFPkObHSjVHlVrxoVQXz7quwNFpz7RY1okNNme49+sVyiTvTRobiLV548Hx/hb1BG+iE7h9493WzFw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "obuf": "~1.1.2"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/@types/pg/node_modules/postgres-date": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/postgres-date/-/postgres-date-2.1.0.tgz",
+      "integrity": "sha512-K7Juri8gtgXVcDfZttFKVmhglp7epKb1K4pgrkLxehjqkrgPhfG6OO8LHLkfaqkbpjNRnra018XwAr1yQFWGcA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/@types/pg/node_modules/postgres-interval": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/postgres-interval/-/postgres-interval-3.0.0.tgz",
+      "integrity": "sha512-BSNDnbyZCXSxgA+1f5UU2GmwhoI0aU5yMxRGO8CdFEcY2BQF9xm/7MqKnYoM1nJDk8nONNWDk9WeSmePFhQdlw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/@types/qs": {
       "version": "6.9.17",
       "resolved": "https://registry.npmjs.org/@types/qs/-/qs-6.9.17.tgz",
@@ -2186,6 +2347,12 @@
         "@types/superagent": "^8.1.0"
       }
     },
+    "node_modules/@types/validator": {
+      "version": "13.12.2",
+      "resolved": "https://registry.npmjs.org/@types/validator/-/validator-13.12.2.tgz",
+      "integrity": "sha512-6SlHBzUW8Jhf3liqrGGXyTJSIFe4nqlJ5A5KaMZ2l/vbM3Wh3KSybots/wfWVzNLK4D1NZluDlSQIbIEPx6oyA==",
+      "license": "MIT"
+    },
     "node_modules/@types/yargs": {
       "version": "17.0.33",
       "resolved": "https://registry.npmjs.org/@types/yargs/-/yargs-17.0.33.tgz",
@@ -2783,7 +2950,6 @@
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-      "dev": true,
       "license": "Python-2.0"
     },
     "node_modules/array-flatten": {
@@ -3363,6 +3529,23 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/class-transformer": {
+      "version": "0.5.1",
+      "resolved": "https://registry.npmjs.org/class-transformer/-/class-transformer-0.5.1.tgz",
+      "integrity": "sha512-SQa1Ws6hUbfC98vKGxZH3KFY0Y1lm5Zm0SY8XX9zbK7FJCyVEac3ATW0RIpwzW+oOfmHE5PMPufDG9hCfoEOMw==",
+      "license": "MIT"
+    },
+    "node_modules/class-validator": {
+      "version": "0.14.1",
+      "resolved": "https://registry.npmjs.org/class-validator/-/class-validator-0.14.1.tgz",
+      "integrity": "sha512-2VEG9JICxIqTpoK1eMzZqaV+u/EiwEJkMGzTrZf6sU/fwsnOITVgYJ8yojSy6CaXtO9V0Cc6ZQZ8h8m4UBuLwQ==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/validator": "^13.11.8",
+        "libphonenumber-js": "^1.10.53",
+        "validator": "^13.9.0"
+      }
+    },
     "node_modules/cli-cursor": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/cli-cursor/-/cli-cursor-3.1.0.tgz",
@@ -3876,6 +4059,27 @@
         "node": ">=6.0.0"
       }
     },
+    "node_modules/dotenv": {
+      "version": "16.4.5",
+      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-16.4.5.tgz",
+      "integrity": "sha512-ZmdL2rui+eB2YwhsWzjInR8LldtZHGDoQ1ugH85ppHKwpUHL7j7rN0Ti9NCnGiQbhaZ11FpR+7ao1dNsmduNUg==",
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://dotenvx.com"
+      }
+    },
+    "node_modules/dotenv-expand": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmjs.org/dotenv-expand/-/dotenv-expand-10.0.0.tgz",
+      "integrity": "sha512-GopVGCpVS1UKH75VKHGuQFqS1Gusej0z4FyQkPdwjil2gNIv+LNsqBlboOzpJFZKVT95GkCyWJbBSdFEFUWI2A==",
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/dunder-proto": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
@@ -6285,7 +6489,6 @@
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-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "argparse": "^2.0.1"
@@ -6412,6 +6615,12 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/libphonenumber-js": {
+      "version": "1.11.17",
+      "resolved": "https://registry.npmjs.org/libphonenumber-js/-/libphonenumber-js-1.11.17.tgz",
+      "integrity": "sha512-Jr6v8thd5qRlOlc6CslSTzGzzQW03uiscab7KHQZX1Dfo4R6n6FDhZ0Hri6/X7edLIDv9gl4VMZXhxTjLnl0VQ==",
+      "license": "MIT"
+    },
     "node_modules/lines-and-columns": {
       "version": "1.2.4",
       "resolved": "https://registry.npmjs.org/lines-and-columns/-/lines-and-columns-1.2.4.tgz",
@@ -6449,7 +6658,6 @@
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-      "dev": true,
       "license": "MIT"
     },
     "node_modules/lodash.memoize": {
@@ -6871,6 +7079,13 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/obuf": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/obuf/-/obuf-1.1.2.tgz",
+      "integrity": "sha512-PX1wu0AmAdPqOL1mWhqmlOd8kOIZQwGZw6rh7uby9fTc5lhaOWFLX3I6R1hrF9k3zUY40e6igsLGkDXK92LJNg==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/on-finished": {
       "version": "2.4.1",
       "resolved": "https://registry.npmjs.org/on-finished/-/on-finished-2.4.1.tgz",
@@ -7128,6 +7343,105 @@
         "node": ">=8"
       }
     },
+    "node_modules/pg": {
+      "version": "8.13.1",
+      "resolved": "https://registry.npmjs.org/pg/-/pg-8.13.1.tgz",
+      "integrity": "sha512-OUir1A0rPNZlX//c7ksiu7crsGZTKSOXJPgtNiHGIlC9H0lO+NC6ZDYksSgBYY/thSWhnSRBv8w1lieNNGATNQ==",
+      "license": "MIT",
+      "dependencies": {
+        "pg-connection-string": "^2.7.0",
+        "pg-pool": "^3.7.0",
+        "pg-protocol": "^1.7.0",
+        "pg-types": "^2.1.0",
+        "pgpass": "1.x"
+      },
+      "engines": {
+        "node": ">= 8.0.0"
+      },
+      "optionalDependencies": {
+        "pg-cloudflare": "^1.1.1"
+      },
+      "peerDependencies": {
+        "pg-native": ">=3.0.1"
+      },
+      "peerDependenciesMeta": {
+        "pg-native": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/pg-cloudflare": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/pg-cloudflare/-/pg-cloudflare-1.1.1.tgz",
+      "integrity": "sha512-xWPagP/4B6BgFO+EKz3JONXv3YDgvkbVrGw2mTo3D6tVDQRh1e7cqVGvyR3BE+eQgAvx1XhW/iEASj4/jCWl3Q==",
+      "license": "MIT",
+      "optional": true
+    },
+    "node_modules/pg-connection-string": {
+      "version": "2.7.0",
+      "resolved": "https://registry.npmjs.org/pg-connection-string/-/pg-connection-string-2.7.0.tgz",
+      "integrity": "sha512-PI2W9mv53rXJQEOb8xNR8lH7Hr+EKa6oJa38zsK0S/ky2er16ios1wLKhZyxzD7jUReiWokc9WK5nxSnC7W1TA==",
+      "license": "MIT"
+    },
+    "node_modules/pg-int8": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/pg-int8/-/pg-int8-1.0.1.tgz",
+      "integrity": "sha512-WCtabS6t3c8SkpDBUlb1kjOs7l66xsGdKpIPZsg4wR+B3+u9UAum2odSsF9tnvxg80h4ZxLWMy4pRjOsFIqQpw==",
+      "license": "ISC",
+      "engines": {
+        "node": ">=4.0.0"
+      }
+    },
+    "node_modules/pg-numeric": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/pg-numeric/-/pg-numeric-1.0.2.tgz",
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+      "dev": true,
+      "license": "ISC",
+      "engines": {
+        "node": ">=4"
+      }
+    },
+    "node_modules/pg-pool": {
+      "version": "3.7.0",
+      "resolved": "https://registry.npmjs.org/pg-pool/-/pg-pool-3.7.0.tgz",
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+      "license": "MIT",
+      "peerDependencies": {
+        "pg": ">=8.0"
+      }
+    },
+    "node_modules/pg-protocol": {
+      "version": "1.7.0",
+      "resolved": "https://registry.npmjs.org/pg-protocol/-/pg-protocol-1.7.0.tgz",
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+      "license": "MIT"
+    },
+    "node_modules/pg-types": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/pg-types/-/pg-types-2.2.0.tgz",
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+      "license": "MIT",
+      "dependencies": {
+        "pg-int8": "1.0.1",
+        "postgres-array": "~2.0.0",
+        "postgres-bytea": "~1.0.0",
+        "postgres-date": "~1.0.4",
+        "postgres-interval": "^1.1.0"
+      },
+      "engines": {
+        "node": ">=4"
+      }
+    },
+    "node_modules/pgpass": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/pgpass/-/pgpass-1.0.5.tgz",
+      "integrity": "sha512-FdW9r/jQZhSeohs1Z3sI1yxFQNFvMcnmfuj4WBMUTxOrAyLMaTcE1aAMBiTlbMNaXvBCQuVi0R7hd8udDSP7ug==",
+      "license": "MIT",
+      "dependencies": {
+        "split2": "^4.1.0"
+      }
+    },
     "node_modules/picocolors": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
@@ -7237,6 +7551,52 @@
         "node": ">=4"
       }
     },
+    "node_modules/postgres-array": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/postgres-array/-/postgres-array-2.0.0.tgz",
+      "integrity": "sha512-VpZrUqU5A69eQyW2c5CA1jtLecCsN2U/bD6VilrFDWq5+5UIEVO7nazS3TEcHf1zuPYO/sqGvUvW62g86RXZuA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=4"
+      }
+    },
+    "node_modules/postgres-bytea": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/postgres-bytea/-/postgres-bytea-1.0.0.tgz",
+      "integrity": "sha512-xy3pmLuQqRBZBXDULy7KbaitYqLcmxigw14Q5sj8QBVLqEwXfeybIKVWiqAXTlcvdvb0+xkOtDbfQMOf4lST1w==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
+    "node_modules/postgres-date": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/postgres-date/-/postgres-date-1.0.7.tgz",
+      "integrity": "sha512-suDmjLVQg78nMK2UZ454hAG+OAW+HQPZ6n++TNDUX+L0+uUlLywnoxJKDou51Zm+zTCjrCl0Nq6J9C5hP9vK/Q==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
+    "node_modules/postgres-interval": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/postgres-interval/-/postgres-interval-1.2.0.tgz",
+      "integrity": "sha512-9ZhXKM/rw350N1ovuWHbGxnGh/SNJ4cnxHiM0rxE4VN41wsg8P8zWn9hv/buK00RP4WvlOyr/RBDiptyxVbkZQ==",
+      "license": "MIT",
+      "dependencies": {
+        "xtend": "^4.0.0"
+      },
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
+    "node_modules/postgres-range": {
+      "version": "1.1.4",
+      "resolved": "https://registry.npmjs.org/postgres-range/-/postgres-range-1.1.4.tgz",
+      "integrity": "sha512-i/hbxIE9803Alj/6ytL7UHQxRvZkI9O4Sy+J3HGc4F4oo/2eQAjTSNJ0bfxyse3bH0nuVesCk+3IRLaMtG3H6w==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/prelude-ls": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.2.1.tgz",
@@ -8071,6 +8431,15 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/split2": {
+      "version": "4.2.0",
+      "resolved": "https://registry.npmjs.org/split2/-/split2-4.2.0.tgz",
+      "integrity": "sha512-UcjcJOWknrNkF6PLX83qcHM6KHgVKNkV62Y8a5uYDVv9ydGQVwAHMKqHdJje1VTWpljG0WYpCDhrCdAOYH4TWg==",
+      "license": "ISC",
+      "engines": {
+        "node": ">= 10.x"
+      }
+    },
     "node_modules/sprintf-js": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/sprintf-js/-/sprintf-js-1.0.3.tgz",
@@ -8311,6 +8680,15 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/swagger-ui-dist": {
+      "version": "5.18.2",
+      "resolved": "https://registry.npmjs.org/swagger-ui-dist/-/swagger-ui-dist-5.18.2.tgz",
+      "integrity": "sha512-J+y4mCw/zXh1FOj5wGJvnAajq6XgHOyywsa9yITmwxIlJbMqITq3gYRZHaeqLVH/eV/HOPphE6NjF+nbSNC5Zw==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@scarf/scarf": "=1.4.0"
+      }
+    },
     "node_modules/symbol-observable": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/symbol-observable/-/symbol-observable-4.0.0.tgz",
@@ -8952,6 +9330,15 @@
         "node": ">=10.12.0"
       }
     },
+    "node_modules/validator": {
+      "version": "13.12.0",
+      "resolved": "https://registry.npmjs.org/validator/-/validator-13.12.0.tgz",
+      "integrity": "sha512-c1Q0mCiPlgdTVVVIJIrBuxNicYE+t/7oKeI9MWLj3fh/uq2Pxh/3eeWbVZ4OcGW1TUf53At0njHw5SMdA3tmMg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.10"
+      }
+    },
     "node_modules/vary": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",

service/package.json

@@ -21,8 +21,13 @@
   },
   "dependencies": {
     "@nestjs/common": "^10.0.0",
+    "@nestjs/config": "^3.3.0",
     "@nestjs/core": "^10.0.0",
     "@nestjs/platform-express": "^10.0.0",
+    "@nestjs/swagger": "^8.1.1",
+    "class-transformer": "^0.5.1",
+    "class-validator": "^0.14.1",
+    "pg": "^8.13.1",
     "reflect-metadata": "^0.2.0",
     "rxjs": "^7.8.1"
   },
@@ -34,6 +39,7 @@
     "@types/express": "^5.0.0",
     "@types/jest": "^29.5.2",
     "@types/node": "^20.3.1",
+    "@types/pg": "^8.11.10",
     "@types/supertest": "^6.0.0",
     "@typescript-eslint/eslint-plugin": "^8.0.0",
     "@typescript-eslint/parser": "^8.0.0",

service/src/app.controller.spec.ts

@@ -1,6 +1,7 @@
 import { Test, TestingModule } from '@nestjs/testing';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
+import { DbClient } from './db';
 
 describe('AppController', () => {
   let appController: AppController;
@@ -8,15 +9,25 @@ describe('AppController', () => {
   beforeEach(async () => {
     const app: TestingModule = await Test.createTestingModule({
       controllers: [AppController],
-      providers: [AppService],
+      providers: [
+        {
+          provide: 'dbClient',
+          useValue: {
+            getNumberOfAllSlots: () => Promise.resolve(123),
+          } satisfies DbClient,
+        },
+        AppService,
+      ],
     }).compile();
 
     appController = app.get<AppController>(AppController);
   });
 
   describe('root', () => {
-    it('should return "Hello World!"', () => {
+    it('should return "Hello World!"', async () => {
-      expect(appController.getHello()).toBe('Hello World!');
+      await expect(appController.getHello()).resolves.toBe(
+        'Hello World! There are 123 total slots.',
+      );
     });
   });
 });

service/src/app.controller.ts

@@ -6,7 +6,7 @@ export class AppController {
   constructor(private readonly appService: AppService) {}
 
   @Get()
-  getHello(): string {
+  async getHello(): Promise<string> {
     return this.appService.getHello();
   }
 }

service/src/app.module.ts

@@ -1,11 +1,24 @@
 import { Module } from '@nestjs/common';
+import { ConfigModule, ConfigService } from '@nestjs/config';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
+import { createDbClient } from './db';
 
 @Module({
-  imports: [],
+  imports: [ConfigModule.forRoot({ ignoreEnvFile: true })],
   controllers: [AppController],
-  providers: [AppService],
+  providers: [
+    {
+      provide: 'dbClient',
+      useFactory: (configService: ConfigService) =>
+        createDbClient(
+          configService.get('PG_CONNECTION_STRING') ??
+            'postgres://postgres:mypassword123!@localhost:5432/coding-challenge',
+        ),
+      inject: [ConfigService],
+    },
+    AppService,
+  ],
 })
 // eslint-disable-next-line @typescript-eslint/no-extraneous-class
 export class AppModule {}

service/src/app.service.ts

@@ -1,8 +1,14 @@
-import { Injectable } from '@nestjs/common';
+import { Inject, Injectable } from '@nestjs/common';
+import { DbClient } from './db';
 
 @Injectable()
 export class AppService {
-  getHello(): string {
+  constructor(
-    return 'Hello World!';
+    @Inject('dbClient')
+    private readonly dbClient: DbClient,
+  ) {}
+
+  async getHello(): Promise<string> {
+    return `Hello World! There are ${await this.dbClient.getNumberOfAllSlots()} total slots.`;
   }
 }

service/src/db/index.ts

@@ -0,0 +1,32 @@
+import { OnModuleDestroy } from '@nestjs/common';
+import { Pool } from 'pg';
+
+export interface DbClient {
+  getNumberOfAllSlots(): Promise<number>;
+}
+
+export const createDbClient = async (
+  connectionString: string,
+): Promise<DbClient & OnModuleDestroy> => {
+  const pool = new Pool({ connectionString });
+
+  {
+    // Checking DB connectivity
+    const connection = await pool.connect();
+    connection.release();
+  }
+
+  return {
+    getNumberOfAllSlots: async () => {
+      const result = await pool.query<{ count: string }>({
+        text: 'select count(*) as count from slots',
+      });
+
+      return parseInt(result.rows[0]?.count ?? '0');
+    },
+
+    onModuleDestroy: async () => {
+      await pool.end();
+    },
+  };
+};

service/src/main.ts

@@ -1,8 +1,10 @@
 import { NestFactory } from '@nestjs/core';
 import { AppModule } from './app.module';
+import { configureApp } from './utils/nestjsHelpers';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
+  configureApp(app);
   await app.listen(process.env['PORT'] ?? 3000);
 }
 void bootstrap();

service/src/utils/nestjsHelpers.ts

@@ -0,0 +1,13 @@
+import { type INestApplication, ValidationPipe } from '@nestjs/common';
+import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
+
+export const configureApp = (app: INestApplication<unknown>) => {
+  app.useGlobalPipes(new ValidationPipe({ transform: true }));
+
+  const config = new DocumentBuilder()
+    .setTitle('Test joyn assignment')
+    .setVersion('1.0')
+    .build();
+  const document = SwaggerModule.createDocument(app, config);
+  SwaggerModule.setup('api', app, document);
+};

service/test/app.e2e-spec.ts

@@ -2,7 +2,8 @@ import { Test, TestingModule } from '@nestjs/testing';
 import { INestApplication } from '@nestjs/common';
 import request from 'supertest';
 import type { App } from 'supertest/types';
-import { AppModule } from './../src/app.module';
+import { AppModule } from '../src/app.module';
+import { configureApp } from '../src/utils/nestjsHelpers';
 
 describe('AppController (e2e)', () => {
   let app: INestApplication<App>;
@@ -13,13 +14,18 @@ describe('AppController (e2e)', () => {
     }).compile();
 
     app = moduleFixture.createNestApplication<INestApplication<App>>();
+    configureApp(app);
     await app.init();
   });
 
+  afterEach(async () => {
+    await app.close();
+  });
+
   it('/ (GET)', () => {
     return request(app.getHttpServer())
       .get('/')
       .expect(200)
-      .expect('Hello World!');
+      .expect('Hello World! There are 18 total slots.');
   });
 });