Добавит схему конфигурации с помощью пакета convict

package.json

@@ -20,6 +20,8 @@
     "mock:server": "json-server mocks/mock-server-data.json --port 3123"
   },
   "devDependencies": {
+    "@types/convict": "6.1.4",
+    "@types/convict-format-with-validator": "6.0.3",
     "@types/node": "18.17.17",
     "@typescript-eslint/eslint-plugin": "6.7.0",
     "@typescript-eslint/parser": "6.7.0",
@@ -39,6 +41,8 @@
     "npm": ">=8"
   },
   "dependencies": {
+    "convict": "6.2.4",
+    "convict-format-with-validator": "6.2.0",
     "dotenv": "16.3.1",
     "got": "13.0.0",
     "pino": "8.15.1"

src/rest/rest.application.ts

@@ -1,10 +1,10 @@
 import { Logger } from '../shared/libs/logger/index.js';
-import {Config} from '../shared/libs/config/index.js';
+import {Config, RestSchema} from '../shared/libs/config/index.js';
 
 export class RestApplication {
   constructor(
     private readonly logger: Logger,
-    private readonly config: Config,
+    private readonly config: Config<RestSchema>,
   ) {}
 
   public async init() {

src/shared/libs/config/config.interface.ts

@@ -1,3 +1,3 @@
-export interface Config {
-  get(key: string): string | undefined;
+export interface Config<U> {
+  get<T extends keyof U>(key: T): U[T];
 }

src/shared/libs/config/index.ts

@@ -1,2 +1,3 @@
 export * from './rest.config.js';
 export * from './config.interface.js';
+export * from './rest.schema.js';

src/shared/libs/config/rest.config.ts

@@ -1,9 +1,10 @@
-import { Config } from './config.interface.js';
+import {Config} from './config.interface.js';
 import {Logger} from '../logger/index.js';
-import {config, DotenvParseOutput} from 'dotenv';
+import {config} from 'dotenv';
+import {configRestSchema, RestSchema} from './rest.schema.js';
 
-export class RestConfig implements Config {
-  private readonly config: NodeJS.ProcessEnv;
+export class RestConfig implements Config<RestSchema> {
+  private readonly config: RestSchema;
 
   constructor(
     private readonly logger: Logger
@@ -14,11 +15,14 @@ export class RestConfig implements Config {
       throw new Error('Can\'t read .env file. Perhaps the file does not exists.');
     }
 
-    this.config = <DotenvParseOutput>parsedOutput.parsed;
+    configRestSchema.load({});
+    configRestSchema.validate({allowed: 'strict', output: this.logger.info});
+
+    this.config = configRestSchema.getProperties();
     this.logger.info('.env file found and successfully parsed!');
   }
 
-  public get(key: string): string | undefined {
+  public get<T extends keyof RestSchema>(key: T): RestSchema[T] {
     return this.config[key];
   }
 }

src/shared/libs/config/rest.schema.ts

@@ -0,0 +1,32 @@
+import convict from 'convict';
+import validator from 'convict-format-with-validator';
+
+convict.addFormats(validator);
+
+
+export type RestSchema = {
+  PORT: number;
+  SALT: string;
+  DB_HOST: string;
+}
+
+export const configRestSchema = convict<RestSchema>({
+  PORT: {
+    doc: 'Port for incoming connections',
+    format: 'port',
+    env: 'PORT',
+    default: 4000
+  },
+  SALT: {
+    doc: 'Salt for password hash',
+    format: String,
+    env: 'SALT',
+    default: null
+  },
+  DB_HOST: {
+    doc: 'IP address of the database server (MongoDB)',
+    format: 'ipaddress',
+    env: 'DB_HOST',
+    default: '127.0.0.1'
+  },
+});