feat: add validation exception (#43)

jest.config.json

@@ -27,9 +27,7 @@
     "^@/generated(.*)$": "<rootDir>/generated$1",
     "^@/guards(.*)$": "<rootDir>/guards$1",
     "^@/interceptors(.*)$": "<rootDir>/api$1",
-    "^@/interfaces(.*)$": "<rootDir>/interfaces$1",
     "^@/shared(.*)$": "<rootDir>/shared$1",
-    "^@/types(.*)$": "<rootDir>/types$1",
     "^@/utils(.*)$": "<rootDir>/utils$1",
     "^@/validators(.*)$": "<rootDir>/validators$1"
   },

src/api/user/user.service.ts

@@ -6,8 +6,8 @@ import { UserEntity } from './entities/user.entity';
 import { InjectRepository } from '@nestjs/typeorm';
 import { plainToInstance } from 'class-transformer';
 import { UserDto } from './dto/user.dto';
-import { I18nContext } from 'nestjs-i18n';
-import { I18nTranslations } from '@/generated/i18n.generated';
+import { ErrorCode } from '@/constants/error-code.constant';
+import { ValidationException } from '@/exceptions/validation.exception';
 
 @Injectable()
 export class UserService {
@@ -16,8 +16,6 @@ export class UserService {
     private readonly userRepository: Repository<UserEntity>,
   ) {}
   async create(dto: CreateUserDto): Promise<UserDto> {
-    const i18n = I18nContext.current<I18nTranslations>();
-
     const { username, email, password } = dto;
 
     // check uniqueness of username/email
@@ -33,7 +31,7 @@ export class UserService {
     });
 
     if (user) {
-      throw new Error(i18n.t('validation.user.errors.userAlreadyExists'));
+      throw new ValidationException(ErrorCode.E001);
     }
 
     const newUser = new UserEntity({

src/common/dto/error.dto.ts

@@ -11,6 +11,9 @@ export class ErrorDto {
   @ApiProperty()
   error: string;
 
+  @ApiPropertyOptional()
+  errorCode?: string;
+
   @ApiProperty()
   message: string;
 

src/constants/error-code.constant.ts

@@ -0,0 +1,12 @@
+export enum ErrorCode {
+  // Common Validation
+  V000 = 'common.validation.error',
+
+  // Validation
+  V001 = 'user.validation.is_empty',
+  V002 = 'user.validation.is_invalid',
+
+  // Error
+  E001 = 'user.error.username_or_email_exists',
+  E002 = 'user.error.not_found',
+}

src/exceptions/validation.exception.ts

@@ -0,0 +1,12 @@
+import { ErrorCode } from '@/constants/error-code.constant';
+import { BadRequestException } from '@nestjs/common';
+
+/**
+ * ValidationException used to throw validation errors with a custom error code and message.
+ * ErrorCode default is V000 (Common Validation)
+ */
+export class ValidationException extends BadRequestException {
+  constructor(error: ErrorCode = ErrorCode.V000, message?: string) {
+    super({ errorCode: error, message });
+  }
+}

src/filters/global-exception.filter.ts

@@ -18,6 +18,8 @@ import { QueryFailedError } from 'typeorm';
 import { ConfigService } from '@nestjs/config';
 import { AllConfigType } from '@/config/config.type';
 import { I18nTranslations } from '@/generated/i18n.generated';
+import { ValidationException } from '@/exceptions/validation.exception';
+import { ErrorCode } from '@/constants/error-code.constant';
 
 @Catch()
 export class GlobalExceptionFilter implements ExceptionFilter {
@@ -37,6 +39,8 @@ export class GlobalExceptionFilter implements ExceptionFilter {
 
     if (exception instanceof UnprocessableEntityException) {
       error = this.handleUnprocessableEntityException(exception);
+    } else if (exception instanceof ValidationException) {
+      error = this.handleValidationException(exception);
     } else if (exception instanceof HttpException) {
       error = this.handleHttpException(exception);
     } else if (exception instanceof QueryFailedError) {
@@ -79,6 +83,29 @@ export class GlobalExceptionFilter implements ExceptionFilter {
     return errorRes;
   }
 
+  private handleValidationException(exception: ValidationException): ErrorDto {
+    const r = exception.getResponse() as {
+      errorCode: ErrorCode;
+      message: string;
+    };
+    const statusCode = exception.getStatus();
+
+    const errorRes = {
+      timestamp: new Date().toISOString(),
+      statusCode,
+      error: STATUS_CODES[statusCode],
+      errorCode:
+        Object.keys(ErrorCode)[Object.values(ErrorCode).indexOf(r.errorCode)],
+      message:
+        r.message ||
+        this.i18n.t(r.errorCode as unknown as keyof I18nTranslations),
+    };
+
+    this.logger.debug(this.logMsg(errorRes, exception));
+
+    return errorRes;
+  }
+
   /**
    * Handles HttpException
    * @param exception HttpException

src/generated/i18n.generated.ts

@@ -4,17 +4,24 @@
 import { Path } from "nestjs-i18n";
 /* prettier-ignore */
 export type I18nTranslations = {
-    "error": {
+    "common": {
+        "validation": {
+            "error": string;
+        };
+    };
+    "user": {
         "unique": {
             "username": string;
             "email": string;
         };
-    };
-    "validation": {
-        "user": {
-            "errors": {
-                "userAlreadyExists": string;
-            };
+        "validation": {
+            "is_empty": string;
+        };
+        "error": {
+            "username_or_email_exists": string;
+            "not_found": string;
+            "invalid_password": string;
+            "invalid_token": string;
         };
     };
 };

src/i18n/en/common.json

@@ -1 +1,5 @@
-{}
+{
+  "validation": {
+    "error": "Common validation"
+  }
+}

src/i18n/en/user.json

@@ -0,0 +1,15 @@
+{
+  "unique": {
+    "username": "User already exists",
+    "email": "User already exists"
+  },
+  "validation": {
+    "is_empty": "Field is required"
+  },
+  "error": {
+    "username_or_email_exists": "Username or email already exists",
+    "not_found": "User not found",
+    "invalid_password": "Invalid password",
+    "invalid_token": "Invalid token"
+  }
+}

src/i18n/jp/common.json

@@ -1 +1,5 @@
-{}
+{
+  "validation": {
+    "error": "Common validation"
+  }
+}

src/i18n/jp/error.json → src/i18n/jp/user.json

@@ -2,5 +2,8 @@
   "unique": {
     "username": "このユーザーは既に存在します",
     "email": "このユーザーは既に存在します"
+  },
+  "validation": {
+    "is_empty": "は必須です"
   }
 }

src/i18n/vi/common.json

@@ -1 +1,5 @@
-{}
+{
+  "validation": {
+    "error": "Common validation"
+  }
+}

src/i18n/vi/error.json → src/i18n/vi/user.json

@@ -2,5 +2,8 @@
   "unique": {
     "username": "Người dùng đã tồn tại",
     "email": "Người dùng đã tồn tại"
+  },
+  "validation": {
+    "is_empty": "Trường này không được để trống"
   }
 }

src/utils/modules-set.ts

@@ -59,7 +59,6 @@ function generateModulesSet() {
           __dirname,
           '../../src/generated/i18n.generated.ts',
         ),
-        throwOnMissingKey: isDevelopment, // throw an error if a key is missing
         logging: isDevelopment, // log info on missing keys
       };
     },

tsconfig.json

@@ -34,9 +34,7 @@
       "@/generated/*": ["src/generated/*"],
       "@/guards/*": ["src/guards/*"],
       "@/interceptors/*": ["src/interceptors/*"],
-      "@/interfaces/*": ["src/interfaces/*"],
       "@/shared/*": ["src/shared/*"],
-      "@/types/*": ["src/types/*"],
       "@/utils/*": ["src/utils/*"],
       "@/validators/*": ["src/validators/*"]
     }