Major refactor and new GraphQL filter

Author: cerpinn

package.json

@@ -13,7 +13,7 @@
   "homepage": "https://github.com/exonest",
   "repository": {
     "type": "git",
-    "url": "https://github.com/exonest/better-validation-pipe"
+    "url": "https://github.com/exonest/better-validation"
   },
   "scripts": {
     "start": "tsdx watch",
@@ -36,16 +36,16 @@
     "singleQuote": true,
     "trailingComma": "es5"
   },
-  "name": "@exonest/better-validation-pipe",
+  "name": "@exonest/better-validation",
   "author": "Alireza Zamani",
-  "module": "dist/better-validation-pipe.esm.js",
+  "module": "dist/better-validation.esm.js",
   "size-limit": [
     {
-      "path": "dist/better-validation-pipe.cjs.production.min.js",
+      "path": "dist/better-validation.cjs.production.min.js",
       "limit": "10 KB"
     },
     {
-      "path": "dist/better-validation-pipe.esm.js",
+      "path": "dist/better-validation.esm.js",
       "limit": "10 KB"
     }
   ],
@@ -72,6 +72,7 @@
   },
   "dependencies": {
     "@nestjs/common": "^8.2.0",
+    "@nestjs/graphql": "^9.1.1",
     "class-transformer": "^0.4.0",
     "class-validator": "^0.13.1",
     "reflect-metadata": "^0.1.13"

src/error-transformer.spec.ts

@@ -0,0 +1,26 @@
+import { ArgumentsHost, Catch, BadRequestException } from '@nestjs/common';
+import { GqlContextType, GqlExceptionFilter } from '@nestjs/graphql';
+
+@Catch(BadRequestException)
+export class GraphqlValidationFilter implements GqlExceptionFilter {
+  catch(exception: BadRequestException, host: ArgumentsHost) {
+    if (host.getType<GqlContextType>() === 'graphql') {
+      // const gqlHost = GqlArgumentsHost.create(host);
+      const response = exception.getResponse() as any;
+
+      if (
+        Array.isArray(response.message) &&
+        Array.isArray(response.message[0].errors) &&
+        typeof response.message[0].field === 'string'
+      ) {
+        return {
+          userErrors: response.message.map((error: any) => ({
+            field: error.path.split('.'),
+            message: error.errors[0],
+          })),
+        };
+      }
+    }
+    return exception;
+  }
+}

src/error-transformer.ts

@@ -1 +1,2 @@
 export * from './validation.pipe';
+export * from './gql-validation.filter';

src/gql-validation.filter.ts

@@ -2,17 +2,30 @@ import {
   ValidationError,
   ValidationPipe as OriginalValidationPipe,
 } from '@nestjs/common';
-import { HttpErrorByCode } from '@nestjs/common/utils/http-error-by-code.util';
-import { transformErrors } from './error-transformer';
+import { iterate } from 'iterare';
 
 export class ValidationPipe extends OriginalValidationPipe {
-  public createExceptionFactory() {
-    return (validationErrors: ValidationError[] = []) => {
-      if (this.isDetailedOutputDisabled) {
-        return new HttpErrorByCode[this.errorHttpStatusCode]();
-      }
-      const errors = transformErrors(validationErrors);
-      return new HttpErrorByCode[this.errorHttpStatusCode](errors);
-    };
+  protected flattenValidationErrors(validationErrors: ValidationError[]) {
+    return (iterate(validationErrors)
+      .map(error => this.mapChildrenToValidationErrors(error))
+      .flatten()
+      .filter(item => !!item.constraints)
+      .map(item => ({
+        errors: Object.values(item.constraints || {}),
+        path: (item as any).path || item.property,
+      }))
+      .filter(errorObject => errorObject.errors.length > 0)
+      .flatten()
+      .toArray() as unknown) as string[];
+  }
+
+  protected prependConstraintsWithParentProp(
+    parentPath: string,
+    error: ValidationError
+  ): ValidationError {
+    return ({
+      path: `${parentPath}.${error.property}`,
+      ...super.prependConstraintsWithParentProp(parentPath, error),
+    } as unknown) as ValidationError;
   }
 }

src/index.ts

@@ -2,6 +2,7 @@
   // see https://www.typescriptlang.org/tsconfig to better understand tsconfigs
   "include": ["src", "types"],
   "compilerOptions": {
+    "experimentalDecorators": true,
     "target": "ES6",
     "module": "esnext",
     "lib": ["dom", "esnext"],