feat: add config validation

Signed-off-by: ayman <aymanshaik1015@gmail.com>

src/configuration.model.ts

@@ -0,0 +1,44 @@
+import {
+    IsBoolean,
+    IsDefined,
+    IsInt,
+    IsNotEmpty,
+    IsString,
+    Max,
+    Min,
+    ValidateNested,
+} from 'class-validator';
+import { Type } from 'class-transformer';
+
+class DbConfig {
+    @IsNotEmpty()
+    @IsString()
+    host: string;
+
+    @IsInt()
+    @Min(0)
+    @Max(65535)
+    port: number;
+
+    @IsNotEmpty()
+    @IsString()
+    username: string;
+
+    @IsNotEmpty()
+    @IsString()
+    password: string;
+
+    @IsNotEmpty()
+    @IsString()
+    databaseName: string;
+
+    @IsBoolean()
+    synchronize: boolean;
+}
+
+export class Config {
+    @IsDefined()
+    @ValidateNested()
+    @Type(() => DbConfig)
+    db: DbConfig;
+}

src/configuration.ts

@@ -2,6 +2,9 @@ import { join } from 'path';
 import { readFileSync } from 'fs';
 import { load } from 'js-yaml';
 import { camelToSnakeCase } from '@/common/common';
+import { Config } from '@/configuration.model';
+import { validateSync } from 'class-validator';
+import { plainToClass } from 'class-transformer';
 
 const getConfigFilePath = () => {
     switch (process.env.NODE_ENV) {
@@ -40,5 +43,18 @@ export default () => {
         any
     >;
     mergeEnvVariablesRecursive(config);
+
+    const validateConfig = plainToClass(Config, config, {
+        enableImplicitConversion: true,
+    });
+
+    const errors = validateSync(validateConfig, {
+        skipMissingProperties: true,
+    });
+
+    if (errors.length > 0) {
+        throw new Error(errors.toString());
+    }
+
     return config;
 };