Nestia Guide Documents

Outline

@nestia/core

export function TypedBody(): ParameterDecorator;

Request body decorator 20,000x faster, even easy to use.

@TypedBody() is a decorator function parsing application/json typed request body, and validates the request body value type through typia.assert<T>() function. If the request body is not following the promised type, 400 bad request error would be thrown.

It is almost same with original @Body() function of NestJS, however, 20,000x faster.

Also, @TypedBody() is much more easier to use than class-validator, because it can use pure TypeScript type. If you can’t understand the word “pure TypeScript type”, then move to below #How to use section and read the IBbsArticle.IUpdate interface type. You may understand what it means.

If you want other Content-Type, use one of below:

application/x-www-form-urlencoded: @TypedQuery.Body().
multipart/form-data: @TypedFormData.Body()

⚠️

@TypedBody() is not essential for Swagger Documents or SDK Library building.

Therefore, it is not a matter to use @TypedBody() or @Body() of the original NestJS.

How to use

IBbsArticle.ts

import { tags } from "typia";
 
export interface IBbsArticle extends IBbsArticle.IStore {
  id: string & tags.Format<"uuid">;
  created_at: string & tags.Format<"date-time">;
}
export namespace IBbsArticle {
  export interface IStore {
    title: string & tags.MinLength<3> & tags.MaxLength<50>;
    body: string;
    files: IAttachmentFile[];
  }
}

IAttachmentFile.ts

import { tags } from "typia";
 
export interface IAttachmentFile {
  name: null | (string & tags.MinLength<1> & tags.MaxLength<255>);
  extension: null | (string & tags.MinLength<1> & tags.MaxLength<8>);
  url: string & tags.Format<"url">;
}

BbsArticlesController.ts

import { TypedBody, TypedRoute } from "@nestia/core";
import { Controller } from "@nestjs/common";
import { tags } from "typia";
 
import { IBbsArticle } from "./IBbsArticle";
 
@Controller("bbs/articles")
export class BbsArticlesController {
  @TypedRoute.Post()
  public async store(
    @TypedBody() input: IBbsArticle.IStore,
  ): Promise<IBbsArticle> {
    return {
      ...input,
      id: "2b5e21d8-0e44-4482-bd3e-4540dee7f3d6",
      created_at: "2023-04-23T12:04:54.168Z",
    };
  }
}

BbsArticlesController.js

"use strict";
var __decorate =
  (this && this.__decorate) ||
  function (decorators, target, key, desc) {
    var c = arguments.length,
      r =
        c < 3
          ? target
          : desc === null
          ? (desc = Object.getOwnPropertyDescriptor(target, key))
          : desc,
      d;
    if (typeof Reflect === "object" && typeof Reflect.decorate === "function")
      r = Reflect.decorate(decorators, target, key, desc);
    else
      for (var i = decorators.length - 1; i >= 0; i--)
        if ((d = decorators[i]))
          r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
    return c > 3 && r && Object.defineProperty(target, key, r), r;
  };
var __metadata =
  (this && this.__metadata) ||
  function (k, v) {
    if (typeof Reflect === "object" && typeof Reflect.metadata === "function")
      return Reflect.metadata(k, v);
  };
var __param =
  (this && this.__param) ||
  function (paramIndex, decorator) {
    return function (target, key) {
      decorator(target, key, paramIndex);
    };
  };
var __awaiter =
  (this && this.__awaiter) ||
  function (thisArg, _arguments, P, generator) {
    function adopt(value) {
      return value instanceof P
        ? value
        : new P(function (resolve) {
            resolve(value);
          });
    }
    return new (P || (P = Promise))(function (resolve, reject) {
      function fulfilled(value) {
        try {
          step(generator.next(value));
        } catch (e) {
          reject(e);
        }
      }
      function rejected(value) {
        try {
          step(generator["throw"](value));
        } catch (e) {
          reject(e);
        }
      }
      function step(result) {
        result.done
          ? resolve(result.value)
          : adopt(result.value).then(fulfilled, rejected);
      }
      step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
  };
Object.defineProperty(exports, "__esModule", { value: true });
exports.BbsArticlesController = void 0;
const core_1 = require("@nestia/core");
const common_1 = require("@nestjs/common");
let BbsArticlesController = class BbsArticlesController {
  store(input) {
    return __awaiter(this, void 0, void 0, function* () {
      return Object.assign(Object.assign({}, input), {
        id: "2b5e21d8-0e44-4482-bd3e-4540dee7f3d6",
        created_at: "2023-04-23T12:04:54.168Z",
      });
    });
  }
};
exports.BbsArticlesController = BbsArticlesController;
__decorate(
  [
    core_1.TypedRoute.Post({
      type: "assert",
      assert: (input) => {
        const assert = (input) => {
          const __is = (input) => {
            const $io0 = (input) =>
              "string" === typeof input.id &&
              /^(?:[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}|00000000-0000-0000-0000-000000000000)$/i.test(
                input.id,
              ) &&
              "string" === typeof input.created_at &&
              !isNaN(new Date(input.created_at).getTime()) &&
              "string" === typeof input.title &&
              3 <= input.title.length &&
              input.title.length <= 50 &&
              "string" === typeof input.body &&
              Array.isArray(input.files) &&
              input.files.every(
                (elem) =>
                  "object" === typeof elem && null !== elem && $io1(elem),
              );
            const $io1 = (input) =>
              (null === input.name ||
                ("string" === typeof input.name &&
                  1 <= input.name.length &&
                  input.name.length <= 255)) &&
              (null === input.extension ||
                ("string" === typeof input.extension &&
                  1 <= input.extension.length &&
                  input.extension.length <= 8)) &&
              "string" === typeof input.url &&
              /^[a-zA-Z0-9]+:\/\/(?:www.)?[-a-zA-Z0-9@:%._+~#=]{1,256}.[a-zA-Z0-9()]{1,6}\b(?:[-a-zA-Z0-9()@:%_+.~#?&/=]*)$/.test(
                input.url,
              );
            return "object" === typeof input && null !== input && $io0(input);
          };
          if (false === __is(input))
            ((input, _path, _exceptionable = true) => {
              const $guard = core_1.TypedRoute.Post.guard;
              const $ao0 = (input, _path, _exceptionable = true) =>
                (("string" === typeof input.id &&
                  (/^(?:[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}|00000000-0000-0000-0000-000000000000)$/i.test(
                    input.id,
                  ) ||
                    $guard(_exceptionable, {
                      path: _path + ".id",
                      expected: 'string & Format<"uuid">',
                      value: input.id,
                    }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".id",
                    expected: '(string & Format<"uuid">)',
                    value: input.id,
                  })) &&
                (("string" === typeof input.created_at &&
                  (!isNaN(new Date(input.created_at).getTime()) ||
                    $guard(_exceptionable, {
                      path: _path + ".created_at",
                      expected: 'string & Format<"date-time">',
                      value: input.created_at,
                    }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".created_at",
                    expected: '(string & Format<"date-time">)',
                    value: input.created_at,
                  })) &&
                (("string" === typeof input.title &&
                  (3 <= input.title.length ||
                    $guard(_exceptionable, {
                      path: _path + ".title",
                      expected: "string & MinLength<3>",
                      value: input.title,
                    })) &&
                  (input.title.length <= 50 ||
                    $guard(_exceptionable, {
                      path: _path + ".title",
                      expected: "string & MaxLength<50>",
                      value: input.title,
                    }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".title",
                    expected: "(string & MinLength<3> & MaxLength<50>)",
                    value: input.title,
                  })) &&
                ("string" === typeof input.body ||
                  $guard(_exceptionable, {
                    path: _path + ".body",
                    expected: "string",
                    value: input.body,
                  })) &&
                (((Array.isArray(input.files) ||
                  $guard(_exceptionable, {
                    path: _path + ".files",
                    expected: "Array<IAttachmentFile>",
                    value: input.files,
                  })) &&
                  input.files.every(
                    (elem, _index1) =>
                      ((("object" === typeof elem && null !== elem) ||
                        $guard(_exceptionable, {
                          path: _path + ".files[" + _index1 + "]",
                          expected: "IAttachmentFile",
                          value: elem,
                        })) &&
                        $ao1(
                          elem,
                          _path + ".files[" + _index1 + "]",
                          true && _exceptionable,
                        )) ||
                      $guard(_exceptionable, {
                        path: _path + ".files[" + _index1 + "]",
                        expected: "IAttachmentFile",
                        value: elem,
                      }),
                  )) ||
                  $guard(_exceptionable, {
                    path: _path + ".files",
                    expected: "Array<IAttachmentFile>",
                    value: input.files,
                  }));
              const $ao1 = (input, _path, _exceptionable = true) =>
                (null === input.name ||
                  ("string" === typeof input.name &&
                    (1 <= input.name.length ||
                      $guard(_exceptionable, {
                        path: _path + ".name",
                        expected: "string & MinLength<1>",
                        value: input.name,
                      })) &&
                    (input.name.length <= 255 ||
                      $guard(_exceptionable, {
                        path: _path + ".name",
                        expected: "string & MaxLength<255>",
                        value: input.name,
                      }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".name",
                    expected:
                      "((string & MinLength<1> & MaxLength<255>) | null)",
                    value: input.name,
                  })) &&
                (null === input.extension ||
                  ("string" === typeof input.extension &&
                    (1 <= input.extension.length ||
                      $guard(_exceptionable, {
                        path: _path + ".extension",
                        expected: "string & MinLength<1>",
                        value: input.extension,
                      })) &&
                    (input.extension.length <= 8 ||
                      $guard(_exceptionable, {
                        path: _path + ".extension",
                        expected: "string & MaxLength<8>",
                        value: input.extension,
                      }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".extension",
                    expected: "((string & MinLength<1> & MaxLength<8>) | null)",
                    value: input.extension,
                  })) &&
                (("string" === typeof input.url &&
                  (/^[a-zA-Z0-9]+:\/\/(?:www.)?[-a-zA-Z0-9@:%._+~#=]{1,256}.[a-zA-Z0-9()]{1,6}\b(?:[-a-zA-Z0-9()@:%_+.~#?&/=]*)$/.test(
                    input.url,
                  ) ||
                    $guard(_exceptionable, {
                      path: _path + ".url",
                      expected: 'string & Format<"url">',
                      value: input.url,
                    }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".url",
                    expected: '(string & Format<"url">)',
                    value: input.url,
                  }));
              return (
                ((("object" === typeof input && null !== input) ||
                  $guard(true, {
                    path: _path + "",
                    expected: "IBbsArticle",
                    value: input,
                  })) &&
                  $ao0(input, _path + "", true)) ||
                $guard(true, {
                  path: _path + "",
                  expected: "IBbsArticle",
                  value: input,
                })
              );
            })(input, "$input", true);
          return input;
        };
        const stringify = (input) => {
          const $io1 = (input) =>
            (null === input.name ||
              ("string" === typeof input.name &&
                1 <= input.name.length &&
                input.name.length <= 255)) &&
            (null === input.extension ||
              ("string" === typeof input.extension &&
                1 <= input.extension.length &&
                input.extension.length <= 8)) &&
            "string" === typeof input.url &&
            /^[a-zA-Z0-9]+:\/\/(?:www.)?[-a-zA-Z0-9@:%._+~#=]{1,256}.[a-zA-Z0-9()]{1,6}\b(?:[-a-zA-Z0-9()@:%_+.~#?&/=]*)$/.test(
              input.url,
            );
          const $string = core_1.TypedRoute.Post.string;
          const $so0 = (input) =>
            `{"id":${$string(input.id)},"created_at":${$string(
              input.created_at,
            )},"title":${$string(input.title)},"body":${$string(
              input.body,
            )},"files":${`[${input.files
              .map((elem) => $so1(elem))
              .join(",")}]`}}`;
          const $so1 = (input) =>
            `{"name":${
              null !== input.name ? $string(input.name) : "null"
            },"extension":${
              null !== input.extension ? $string(input.extension) : "null"
            },"url":${$string(input.url)}}`;
          return $so0(input);
        };
        return stringify(assert(input));
      },
    }),
    __param(
      0,
      (0, core_1.TypedBody)({
        type: "assert",
        assert: (input) => {
          const __is = (input) => {
            const $io0 = (input) =>
              "string" === typeof input.title &&
              3 <= input.title.length &&
              input.title.length <= 50 &&
              "string" === typeof input.body &&
              Array.isArray(input.files) &&
              input.files.every(
                (elem) =>
                  "object" === typeof elem && null !== elem && $io1(elem),
              );
            const $io1 = (input) =>
              (null === input.name ||
                ("string" === typeof input.name &&
                  1 <= input.name.length &&
                  input.name.length <= 255)) &&
              (null === input.extension ||
                ("string" === typeof input.extension &&
                  1 <= input.extension.length &&
                  input.extension.length <= 8)) &&
              "string" === typeof input.url &&
              /^[a-zA-Z0-9]+:\/\/(?:www.)?[-a-zA-Z0-9@:%._+~#=]{1,256}.[a-zA-Z0-9()]{1,6}\b(?:[-a-zA-Z0-9()@:%_+.~#?&/=]*)$/.test(
                input.url,
              );
            return "object" === typeof input && null !== input && $io0(input);
          };
          if (false === __is(input))
            ((input, _path, _exceptionable = true) => {
              const $guard = core_1.TypedBody.guard;
              const $ao0 = (input, _path, _exceptionable = true) =>
                (("string" === typeof input.title &&
                  (3 <= input.title.length ||
                    $guard(_exceptionable, {
                      path: _path + ".title",
                      expected: "string & MinLength<3>",
                      value: input.title,
                    })) &&
                  (input.title.length <= 50 ||
                    $guard(_exceptionable, {
                      path: _path + ".title",
                      expected: "string & MaxLength<50>",
                      value: input.title,
                    }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".title",
                    expected: "(string & MinLength<3> & MaxLength<50>)",
                    value: input.title,
                  })) &&
                ("string" === typeof input.body ||
                  $guard(_exceptionable, {
                    path: _path + ".body",
                    expected: "string",
                    value: input.body,
                  })) &&
                (((Array.isArray(input.files) ||
                  $guard(_exceptionable, {
                    path: _path + ".files",
                    expected: "Array<IAttachmentFile>",
                    value: input.files,
                  })) &&
                  input.files.every(
                    (elem, _index1) =>
                      ((("object" === typeof elem && null !== elem) ||
                        $guard(_exceptionable, {
                          path: _path + ".files[" + _index1 + "]",
                          expected: "IAttachmentFile",
                          value: elem,
                        })) &&
                        $ao1(
                          elem,
                          _path + ".files[" + _index1 + "]",
                          true && _exceptionable,
                        )) ||
                      $guard(_exceptionable, {
                        path: _path + ".files[" + _index1 + "]",
                        expected: "IAttachmentFile",
                        value: elem,
                      }),
                  )) ||
                  $guard(_exceptionable, {
                    path: _path + ".files",
                    expected: "Array<IAttachmentFile>",
                    value: input.files,
                  }));
              const $ao1 = (input, _path, _exceptionable = true) =>
                (null === input.name ||
                  ("string" === typeof input.name &&
                    (1 <= input.name.length ||
                      $guard(_exceptionable, {
                        path: _path + ".name",
                        expected: "string & MinLength<1>",
                        value: input.name,
                      })) &&
                    (input.name.length <= 255 ||
                      $guard(_exceptionable, {
                        path: _path + ".name",
                        expected: "string & MaxLength<255>",
                        value: input.name,
                      }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".name",
                    expected:
                      "((string & MinLength<1> & MaxLength<255>) | null)",
                    value: input.name,
                  })) &&
                (null === input.extension ||
                  ("string" === typeof input.extension &&
                    (1 <= input.extension.length ||
                      $guard(_exceptionable, {
                        path: _path + ".extension",
                        expected: "string & MinLength<1>",
                        value: input.extension,
                      })) &&
                    (input.extension.length <= 8 ||
                      $guard(_exceptionable, {
                        path: _path + ".extension",
                        expected: "string & MaxLength<8>",
                        value: input.extension,
                      }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".extension",
                    expected: "((string & MinLength<1> & MaxLength<8>) | null)",
                    value: input.extension,
                  })) &&
                (("string" === typeof input.url &&
                  (/^[a-zA-Z0-9]+:\/\/(?:www.)?[-a-zA-Z0-9@:%._+~#=]{1,256}.[a-zA-Z0-9()]{1,6}\b(?:[-a-zA-Z0-9()@:%_+.~#?&/=]*)$/.test(
                    input.url,
                  ) ||
                    $guard(_exceptionable, {
                      path: _path + ".url",
                      expected: 'string & Format<"url">',
                      value: input.url,
                    }))) ||
                  $guard(_exceptionable, {
                    path: _path + ".url",
                    expected: '(string & Format<"url">)',
                    value: input.url,
                  }));
              return (
                ((("object" === typeof input && null !== input) ||
                  $guard(true, {
                    path: _path + "",
                    expected: "IBbsArticle.IStore",
                    value: input,
                  })) &&
                  $ao0(input, _path + "", true)) ||
                $guard(true, {
                  path: _path + "",
                  expected: "IBbsArticle.IStore",
                  value: input,
                })
              );
            })(input, "$input", true);
          return input;
        },
      }),
    ),
    __metadata("design:type", Function),
    __metadata("design:paramtypes", [Object]),
    __metadata("design:returntype", Promise),
  ],
  BbsArticlesController.prototype,
  "store",
  null,
);
exports.BbsArticlesController = BbsArticlesController = __decorate(
  [(0, common_1.Controller)("bbs/articles")],
  BbsArticlesController,
);

Just call @TypedBody() function on the request body parameter, that’s all.

Nestia will analyze your type (IBbsArticle.IUpdate), and writes optimal code for the target type, in the compilation level. If you click the “Complied JavaScript File” tab of above, you can see the optimal validation code.

Such optimization is called AOT (Ahead of Time) compilation, and it is the secret of @TypedBody.

Special Tags

You can enhance validation logic, of @TypedBody(), through special tags.

You know what? @TypedBody() utilizes typia.assert<T>() function for request body data validation, and the typia.assert<T>() function supports additional type checking logics through type and comment tags. For reference, “Type Tag” means a intersection type with atomic type and special tag type of typia like number & tags.Type<"uint32">, and “Comment Tag” means a comment starting from @ symbol following @${name} ${value} format.

With those type and comment tags, you can add additional validation logics. If you want to add a custom validation logic, you also can do it. Read below Guide Docments of typia, and see the example code. You may understand how to utilize such type and comment tags, in a few minutes.

typia > Validators > Custom Tags

examples/src/is-special-tags.ts

import typia, { tags } from "typia";
 
export const checkSpecialTag = typia.createIs<SpecialTag>();
 
interface SpecialTag {
  int32: number & tags.Type<"int32">;
  range?: number & tags.ExclusiveMinimum<19> & tags.Maximum<100>;
  minLength: string & tags.MinLength<3>;
  pattern: string & tags.Pattern<"^[a-z]+$">;
  date: null | (string & tags.Format<"date">);
  ip: string & (tags.Format<"ipv4"> | tags.Format<"ipv6">);
  uuids: Array<string & tags.Format<"uuid">> &
    tags.MinItems<3> &
    tags.MaxItems<100>;
}

examples/bin/is-special-tags.js

"use strict";
var __importDefault =
  (this && this.__importDefault) ||
  function (mod) {
    return mod && mod.__esModule ? mod : { default: mod };
  };
Object.defineProperty(exports, "__esModule", { value: true });
exports.checkSpecialTag = void 0;
const typia_1 = __importDefault(require("typia"));
const checkSpecialTag = (input) => {
  const $io0 = (input) =>
    "number" === typeof input.int32 &&
    Math.floor(input.int32) === input.int32 &&
    -2147483648 <= input.int32 &&
    input.int32 <= 2147483647 &&
    (undefined === input.range ||
      ("number" === typeof input.range &&
        19 < input.range &&
        input.range <= 100)) &&
    "string" === typeof input.minLength &&
    3 <= input.minLength.length &&
    "string" === typeof input.pattern &&
    /^[a-z]+$/.test(input.pattern) &&
    (null === input.date ||
      ("string" === typeof input.date &&
        /^(d{4})-(d{2})-(d{2})$/.test(input.date))) &&
    "string" === typeof input.ip &&
    (/^(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(
      input.ip,
    ) ||
      /^(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]).){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]).){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))$/.test(
        input.ip,
      )) &&
    Array.isArray(input.uuids) &&
    3 <= input.uuids.length &&
    input.uuids.length <= 100 &&
    input.uuids.every(
      (elem) =>
        "string" === typeof elem &&
        /^(?:[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}|00000000-0000-0000-0000-000000000000)$/i.test(
          elem,
        ),
    );
  return "object" === typeof input && null !== input && $io0(input);
};
exports.checkSpecialTag = checkSpecialTag;

`EncryptedBody`

Encrypted request body decorator function.

@EncryptedBody() is a decorator function similar with @TypedBody(), but it encrypts the request body through AES-128/256-CBC algorithm like below. Therefore, it would be slower than @TypedBody(), but it guarantees the security of request body data.

AES-128/256
CBC mode
PKCS #5 Padding
Base64 Encoding

For reference, such encryption spec is not supported in the Swagger-UI. Instead, SDK (Software Development Kit) generated by @nestia/sdk supports it. Thus, you have to build and distribute the SDK library to the client developers when using such encryption decorators.

Configuration

tsconfig.json

{
  "compilerOptions": {
    "strict": true,
    "plugins": [
      { "transform": "typia/lib/transform" },
      {
        "transform": "@nestia/core/lib/transform",
        "validate": "assert",
        // "llm": {
        //   "model": "chatgpt",
        //   "strict": true,
        // },
      }
    ]
  }
}

Change type validation function to another one.

If you configure validate property of plugin defined in the tsconfig.json file, you can change the @TypedBody() to use another validation function instead of the default typia.assert<T> function. For example, if you want to use typia.validateEquals<T>() function instead, then set the validate property to validateEquals.

Below is the list of available validation functions.

is or equals: check validation only, and do not reveal the reason why
assert or assertEquals: find the 1st type error with reason
validate or validateEquals: find every type errors with detailed reasons
assertPrune or validatePrune: prune extra properties with type checking
assertClone or validateClone: deep clone with type checking for faster pruning

Also, if you configure llm property of the plugin, @nestia/core considers that your backend application has been developed for LLM function calling, and validates the request/response body types following the target LLM model’s restrictions.

For example, if you configure chatgpt with strict option, dynamic properties and optional properties are not allowed in the request/response body types. If your some request/response body types are not following the target LLM model’s restrictions, @nestia/core will throw a compilation error.

Here is the list of available LLM models. Read their definitions, and follow their restrictions.

Supported schemas
- "chatgpt": (IChatGptSchema), OpenAI ChatGPT
- "claude": (IClaudeSchema), Anthropic Claude
- "gemini": (IGeminiSchema), Google Gemini
- "llama": (ILlamaSchema), Meta Llama
Midldle layer schemas
- "3.0": (ILlmSchemaV3), middle layer based on OpenAPI v3.0 specification
- "3.1": (ILlmSchemaV3_1), middle layer based on OpenAPI v3.1 specification

Benchmark

Super-fast and super-safe.

Nestia utilizes typia, and NestJS uses class-validator. One thing amazing is, typia is maximum 20,000x faster than class-validator of NestJS. Color of class-transformer is skyblue, and can you find the skyblue color in the below benchmark graph? It may hard to find because class-validator is extremely slow.

Assert Function Benchmark

Measured on AMD R9-7940HS, Rog Flow X13

Furthermore, while other libraries can’t validate complicate union types, typia can validate every TypeScript types. However, in the class-validator case, it always be failed when any type of complicate comes. I can’t understand why NestJS has adopted such slow and unstable library.

Moreover, only typia can utilize pure TypeScript type, without any extra schema definition. Beside, all of other libraries require extra and duplicated schema definition, different with pure TypeScript type. Nestia is using such wonderful, super-fast and super-fast typia library.

TypeBox requires TypeBox schema
ajv requires JSON schema definition
io-ts requires io-ts schema
zod requires zod schema
class-validator requires DTO class with decorator function calls

Components	`typia`	`TypeBox`	`ajv`	`io-ts`	`zod`	`C.V.`
Easy to use	✅	❌	❌	❌	❌	❌
Object (simple)	✔	✔	✔	✔	✔	✔
Object (hierarchical)	✔	✔	✔	✔	✔	✔
Object (recursive)	✔	❌	✔	✔	✔	✔
Object (union, implicit)	✅	❌	❌	❌	❌	❌
Object (union, explicit)	✔	✔	✔	✔	✔	❌
Object (additional tags)	✔	✔	✔	✔	✔	✔
Object (template literal types)	✔	✔	✔	❌	❌	❌
Object (dynamic properties)	✔	✔	✔	❌	❌	❌
Array (rest tuple)	✅	❌	❌	❌	❌	❌
Array (hierarchical)	✔	✔	✔	✔	✔	✔
Array (recursive)	✔	✔	✔	✔	✔	❌
Array (recursive, union)	✔	✔	❌	✔	✔	❌
Array (R+U, implicit)	✅	❌	❌	❌	❌	❌
Ultimate Union Type	✅	❌	❌	❌	❌	❌

C.V. means class-validator

TypedRoute TypedParam