Improved error messages for class-validator

Author: decs

.changeset/lovely-bobcats-hang.md

@@ -0,0 +1,7 @@
+---
+'@typeschema/class-validator': minor
+'@typeschema/main': patch
+'@typeschema/all': patch
+---
+
+Improved error messages for class-validator

README.md

@@ -44,11 +44,13 @@ describe('class-validator', () => {
     @IsDateString()
     updatedAt!: string;
 
+    @IsOptional()
     @ValidateNested()
-    nested!: NestedSchema;
+    nested?: NestedSchema;
+
     @IsOptional()
     @ValidateNested()
-    nestedArray?: NestedSchema[];
+    nestedArray?: Array<NestedSchema>;
   }
   const schema = Schema;
 
@@ -67,7 +69,7 @@ describe('class-validator', () => {
     email: '[email protected]',
     id: 'c4a760a8-dbcf-4e14-9f39-645a8e933d74',
     name: 'John Doe',
-    updatedAt: '2021-01-01T00:00:00.000Z'
+    updatedAt: '2021-01-01T00:00:00.000Z',
   };
 
   const badNestedData = {
@@ -100,7 +102,7 @@ describe('class-validator', () => {
         {
           message: 'age must be an integer number',
           path: ['age'],
-        }
+        },
       ],
       success: false,
     });
@@ -109,20 +111,20 @@ describe('class-validator', () => {
       issues: [
         {
           message: 'value should not be empty',
-          path: ['nested.value'],
+          path: ['nested', 'value'],
         },
         {
           message: 'value must be a string',
-          path: ['nested.value'],
+          path: ['nested', 'value'],
         },
         {
           message: 'value should not be empty',
-          path: ['nestedArray[0].value'],
+          path: ['nestedArray', 0, 'value'],
         },
         {
           message: 'value must be a string',
-          path: ['nestedArray[0].value'],
-        }
+          path: ['nestedArray', 0, 'value'],
+        },
       ],
       success: false,
     });

packages/all/src/__tests__/class-validator.test.ts

@@ -1,36 +1,34 @@
-/* eslint-disable prettier/prettier */
 import type {AdapterResolver} from './resolver';
 import type {ValidationAdapter, ValidationIssue} from '@typeschema/core';
 
 import {memoize} from '@typeschema/core';
-import { ValidationError } from "class-validator";
+import {ValidationError} from 'class-validator';
 
 const importValidationModule = memoize(async () => {
   const {validate} = await import('class-validator');
   return {validate};
 });
 
+function getIssues(
+  error: ValidationError,
+  parentPath: Array<PropertyKey>,
+): Array<ValidationIssue> {
+  const path = [
+    ...parentPath,
+    Number.isInteger(+error.property) ? +error.property : error.property,
+  ];
+  return Object.values(error.constraints ?? {})
+    .map((message): ValidationIssue => ({message, path}))
+    .concat(
+      error.children?.flatMap(childError => getIssues(childError, path)) ?? [],
+    );
+}
+
 export const validationAdapter: ValidationAdapter<
   AdapterResolver
 > = async schema => {
   const {validate} = await importValidationModule();
   return async data => {
-    function getIssues(error: ValidationError, parentPath = ""): ValidationIssue[] {
-      const currentPath = parentPath
-        ? Number.isInteger(+error.property) ? `${parentPath}[${error.property}]` : `${parentPath}.${error.property}`
-        : error.property;
-      const constraints = error.constraints ? Object.values(error.constraints) : [];
-      const childIssues = error.children ? error.children.flatMap(childError => getIssues(childError, currentPath)) : [];
-
-      return [
-          ...constraints.map((message) => ({
-              message: message,
-              path: [currentPath],
-          })),
-          ...childIssues
-      ];
-    }
-
     const errors = await validate(Object.assign(new schema(), data));
     if (errors.length === 0) {
       return {
@@ -40,7 +38,7 @@ export const validationAdapter: ValidationAdapter<
       };
     }
     return {
-      issues: errors.flatMap(error => getIssues(error)),
+      issues: errors.flatMap(error => getIssues(error, [])),
       success: false,
     };
   };