first

.dockerignore

+# compiled output
+/dist
+/node_modules
+
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# OS
+.DS_Store
+
+# Tests
+/coverage
+/.nyc_output
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+/data
+/output
+/config.yaml
+
+.git*
+Dockerfile
+.dockerignore
+/tests

.eslintignore

+webpack.config.js
+dist/*
+build/*
+*.js

.eslintrc.js

+module.exports = {
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    project: 'tsconfig.json',
+    sourceType: 'module',
+  },
+  plugins: ['@typescript-eslint/eslint-plugin'],
+  extends: [
+    'plugin:@typescript-eslint/recommended',
+    'plugin:prettier/recommended',
+  ],
+  root: true,
+  env: {
+    node: true,
+    jest: true,
+  },
+  ignorePatterns: ['.eslintrc.js'],
+  rules: {
+    '@typescript-eslint/interface-name-prefix': 'off',
+    '@typescript-eslint/explicit-function-return-type': 'off',
+    '@typescript-eslint/explicit-module-boundary-types': 'off',
+    '@typescript-eslint/no-explicit-any': 'off',
+  },
+};

.gitignore

+# compiled output
+/dist
+/node_modules
+
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# OS
+.DS_Store
+
+# Tests
+/coverage
+/.nyc_output
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+/data
+/output
+/config.yaml

.gitlab-ci.yml

+stages:
+  - install
+  - build
+  - deploy
+
+variables:
+  GIT_DEPTH: "1"
+
+npm_ci:
+  stage: install
+  tags:
+    - linux
+  script:
+    - npm ci
+  artifacts:
+    paths:
+      - node_modules
+
+.build_base:
+  stage: build
+  tags:
+    - linux
+  dependencies:
+    - npm_ci
+
+build:
+  extends:
+    - .build_base
+  script:
+    - npm run build
+  artifacts:
+    paths:
+      - dist/
+
+unit-test:
+  extends:
+    - .build_base
+  script:
+    - npm run test
+
+deploy_npm:
+  stage: deploy
+  dependencies:
+    - build
+  tags:
+    - linux
+  script:
+    - apt update;apt -y install coreutils
+    - echo $NPMRC | base64 --decode > ~/.npmrc
+    - npm publish . || true
+  only:
+    - master

.npmignore

+/install-npm.sh
+.git*
+/data
+/output
+/config.yaml
+.idea
+.dockerignore
+Dockerfile
+/src
+/coverage
+/tests
+/dist/tests

.prettierrc

+{
+  "singleQuote": true,
+  "trailingComma": "all"
+}
\ No newline at end of file

Dockerfile

+FROM node:lts-bullseye-slim as base
+LABEL Author="Nanahira <nanahira@momobako.com>"
+
+RUN apt update && apt -y install python3 build-essential && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /var/log/*
+WORKDIR /usr/src/app
+COPY ./package*.json ./
+
+FROM base as builder
+RUN npm ci && npm cache clean --force
+COPY . ./
+RUN npm run build
+
+FROM base
+ENV NODE_ENV production
+RUN npm ci && npm cache clean --force
+COPY --from=builder /usr/src/app/dist ./dist
+
+CMD [ "npm", "start" ]

LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2021 Nanahira
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

README.md

 # nicot
 
-Nest.js interacting with class-validator + OpenAPI + typeorm
\ No newline at end of file
+Nest.js interacting with class-validator + OpenAPI + TypeORM for Nest.js Restful API development.

index.ts

+export * from './src/crud-base';
+export * from './src/bases';
+export * from './src/decorators';
+export * from './src/dto';
+export * from './src/utility';

package.json

+{
+  "name": "nicot",
+  "description": "Nest.js interacting with class-validator + OpenAPI + TypeORM for Nest.js Restful API development.",
+  "version": "1.0.0",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "scripts": {
+    "lint": "eslint --fix .",
+    "build": "rimraf dist && npm run build",
+    "test": "jest --passWithNoTests",
+    "start": "node dist/index.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://code.mycard.moe/3rdeye/nicot.git"
+  },
+  "author": "Nanahira <nanahira@momobako.com>",
+  "license": "MIT",
+  "keywords": [],
+  "bugs": {
+    "url": "https://code.mycard.moe/3rdeye/nicot/issues"
+  },
+  "homepage": "https://code.mycard.moe/3rdeye/nicot",
+  "jest": {
+    "moduleFileExtensions": [
+      "js",
+      "json",
+      "ts"
+    ],
+    "rootDir": "tests",
+    "testRegex": ".*\\.spec\\.ts$",
+    "transform": {
+      "^.+\\.(t|j)s$": "ts-jest"
+    },
+    "collectCoverageFrom": [
+      "**/*.(t|j)s"
+    ],
+    "coverageDirectory": "../coverage",
+    "testEnvironment": "node"
+  },
+  "devDependencies": {
+    "@types/jest": "^28.1.5",
+    "@types/lodash": "^4.14.182",
+    "@types/node": "^18.0.4",
+    "@typescript-eslint/eslint-plugin": "^4.33.0",
+    "@typescript-eslint/parser": "^4.33.0",
+    "eslint": "^7.32.0",
+    "eslint-config-prettier": "^8.5.0",
+    "eslint-plugin-prettier": "^3.4.1",
+    "jest": "^28.1.3",
+    "prettier": "^2.7.1",
+    "rimraf": "^3.0.2",
+    "ts-jest": "^28.0.6",
+    "typescript": "^4.7.4"
+  },
+  "peerDependencies": {
+    "@nestjs/common": "^9.0.3",
+    "@nestjs/swagger": "^6.0.4",
+    "class-transformer": "^0.5.1",
+    "class-validator": "^0.13.2",
+    "typeorm": "^0.3.7"
+  },
+  "dependencies": {
+    "lodash": "^4.17.21"
+  }
+}

src/bases/id-base.ts

+import { TimeBase } from './time-base';
+import { Generated, SelectQueryBuilder } from 'typeorm';
+import { applyQueryProperty } from '../utility/query';
+import {
+  IntColumn,
+  MergePropertyDecorators,
+  NotChangeable,
+  NotWritable,
+  StringColumn,
+} from '../decorators';
+import { IsNotEmpty } from 'class-validator';
+
+export interface IdOptions {
+  description?: string;
+}
+
+export function IdBase(idOptions: IdOptions = {}) {
+  const cl = class IdBase extends TimeBase {
+    id: number;
+    override applyQuery(qb: SelectQueryBuilder<IdBase>, entityName: string) {
+      super.applyQuery(qb, entityName);
+      qb.orderBy(`${entityName}.id`, 'DESC');
+      applyQueryProperty(this, qb, entityName, 'id');
+    }
+  };
+  const dec = MergePropertyDecorators([
+    NotWritable(),
+    IntColumn('bigint', {
+      unsigned: true,
+      description: idOptions.description,
+      columnExtras: { nullable: false, primary: true },
+    }),
+    Reflect.metadata('design:type', Number),
+    Generated('increment'),
+  ]);
+  dec(cl.prototype, 'id');
+  return cl;
+}
+
+export interface StringIdOptions extends IdOptions {
+  length: number;
+  uuid?: boolean;
+}
+
+export function StringIdBase(idOptions: StringIdOptions) {
+  const cl = class StringIdBase extends TimeBase {
+    id: string;
+
+    override applyQuery(
+      qb: SelectQueryBuilder<StringIdBase>,
+      entityName: string,
+    ) {
+      super.applyQuery(qb, entityName);
+      qb.orderBy(`${entityName}.id`, 'ASC');
+      applyQueryProperty(this, qb, entityName, 'id');
+    }
+  };
+  const decs = [
+    NotChangeable(),
+    StringColumn(idOptions.length, {
+      required: !idOptions.uuid,
+      description: idOptions.description,
+      columnExtras: { primary: true, nullable: false },
+    }),
+    Reflect.metadata('design:type', String),
+    IsNotEmpty(),
+  ];
+  if (idOptions.uuid) {
+    decs.push(Generated('uuid'));
+  }
+  const dec = MergePropertyDecorators(decs);
+  dec(cl.prototype, 'id');
+  return cl;
+}

src/bases/index.ts

+export * from './time-base';
+export * from './id-base';

src/bases/time-base.ts

+import { CreateDateColumn, DeleteDateColumn, UpdateDateColumn } from 'typeorm';
+import { PageSettingsDto } from '../dto/page-settings';
+import { NotColumn } from '../decorators';
+
+export interface DeletionWise {
+  deleteTime?: Date;
+}
+
+export interface ImportWise {
+  isValidInCreation(): string | undefined;
+  prepareForSaving(): Promise<void>;
+  afterSaving(): void;
+}
+
+export class TimeBase
+  extends PageSettingsDto
+  implements DeletionWise, ImportWise
+{
+  @CreateDateColumn({ select: false })
+  @NotColumn()
+  createTime: Date;
+
+  @UpdateDateColumn({ select: false })
+  @NotColumn()
+  updateTime: Date;
+
+  @DeleteDateColumn({ select: false })
+  @NotColumn()
+  deleteTime: Date;
+
+  toObject() {
+    return JSON.parse(JSON.stringify(this));
+  }
+
+  isValidInCreation(): string | undefined {
+    return;
+  }
+
+  async prepareForSaving(): Promise<void> {}
+
+  afterSaving() {}
+}
+
+export const TimeBaseFields: (keyof TimeBase)[] = [
+  'createTime',
+  'updateTime',
+  'deleteTime',
+];

src/decorators/access.ts

+import { Expose } from 'class-transformer';
+import { IsOptional } from 'class-validator';
+import { MergePropertyDecorators } from './merge';
+
+export const NotWritable = () =>
+  MergePropertyDecorators([Expose({ groups: ['r'] }), IsOptional()]);
+export const NotChangeable = () => Expose({ groups: ['r', 'c'] });

src/decorators/index.ts

+export * from './access';
+export * from './merge';
+export * from './property';
+export * from './restful';
+export * from './pipes';

src/decorators/merge.ts

+export function MergePropertyDecorators(
+  decs: PropertyDecorator[],
+): PropertyDecorator {
+  return (obj, key) => {
+    for (const dec of decs) {
+      dec(obj, key);
+    }
+  };
+}
+
+export function MergeMethodDecorators(
+  decs: MethodDecorator[],
+): MethodDecorator {
+  return (obj, key, descriptor) => {
+    for (const dec of decs) {
+      dec(obj, key, descriptor);
+    }
+  };
+}
+
+export function MergeClassDecorators(decs: ClassDecorator[]): ClassDecorator {
+  return (obj) => {
+    for (const dec of decs) {
+      dec(obj);
+    }
+  };
+}
+
+export function MergeParameterDecorators(
+  decs: ParameterDecorator[],
+): ParameterDecorator {
+  return (obj, key, index) => {
+    for (const dec of decs) {
+      dec(obj, key, index);
+    }
+  };
+}

src/decorators/pipes.ts

+import { ValidationPipe } from '@nestjs/common';
+
+export const CreatePipe = new ValidationPipe({
+  transform: true,
+  transformOptions: { groups: ['c'], enableImplicitConversion: true },
+});
+
+export const GetPipe = new ValidationPipe({
+  transform: true,
+  transformOptions: { groups: ['r'], enableImplicitConversion: true },
+  skipMissingProperties: true,
+  skipNullProperties: true,
+  skipUndefinedProperties: true,
+});
+
+export const UpdatePipe = new ValidationPipe({
+  transform: true,
+  transformOptions: { groups: ['u'], enableImplicitConversion: true },
+  skipMissingProperties: true,
+  skipNullProperties: true,
+  skipUndefinedProperties: true,
+});

src/decorators/property.ts

+import { ColumnCommonOptions } from 'typeorm/decorator/options/ColumnCommonOptions';
+import { ApiProperty, ApiPropertyOptions } from '@nestjs/swagger';
+import { ColumnWithLengthOptions } from 'typeorm/decorator/options/ColumnWithLengthOptions';
+import { MergePropertyDecorators } from './merge';
+import { Column, Index } from 'typeorm';
+import {
+  IsDate,
+  IsEnum,
+  IsInt,
+  IsNumber,
+  IsOptional,
+  IsString,
+  MaxLength,
+  Min,
+} from 'class-validator';
+import {
+  WithPrecisionColumnType,
+  WithWidthColumnType,
+} from 'typeorm/driver/types/ColumnTypes';
+import { ColumnWithWidthOptions } from 'typeorm/decorator/options/ColumnWithWidthOptions';
+import { ColumnNumericOptions } from 'typeorm/decorator/options/ColumnNumericOptions';
+import { Exclude } from 'class-transformer';
+import { BigintTransformer } from '../utility/bigint';
+
+export interface OpenAPIOptions<T> {
+  description?: string;
+  propertyExtras?: ApiPropertyOptions;
+  default?: T;
+  required?: boolean;
+}
+
+function swaggerDecorator(
+  options: OpenAPIOptions<any>,
+  injected: ApiPropertyOptions = {},
+) {
+  return ApiProperty({
+    default: options.default,
+    required: options.required && options.default == null,
+    example: options.default,
+    description: options.description,
+    ...injected,
+    ...(options.propertyExtras || {}),
+  });
+}
+
+function validatorDecorator(options: OpenAPIOptions<any>) {
+  const decs: PropertyDecorator[] = [];
+  if (!options.required) {
+    decs.push(IsOptional());
+  }
+  return MergePropertyDecorators(decs);
+}
+
+export interface PropertyOptions<T, ColumnEx = unknown>
+  extends OpenAPIOptions<T> {
+  columnExtras?: ColumnCommonOptions & ColumnEx;
+}
+
+function columnDecoratorOptions<T>(
+  options: PropertyOptions<T>,
+): ColumnCommonOptions {
+  return {
+    default: options.default,
+    nullable: !options.required && options.default == null,
+    comment: options.description,
+    ...options.columnExtras,
+  };
+}
+
+export const StringColumn = (
+  length: number,
+  options: PropertyOptions<string, ColumnWithLengthOptions> = {},
+): PropertyDecorator => {
+  return MergePropertyDecorators([
+    Column('varchar', { length, ...columnDecoratorOptions(options) }),
+    IsString(),
+    MaxLength(length),
+    validatorDecorator(options),
+    swaggerDecorator(options, { type: String, maxLength: length }),
+  ]);
+};
+
+export const IntColumn = (
+  type: WithWidthColumnType,
+  options: PropertyOptions<string, ColumnWithWidthOptions> & {
+    unsigned?: boolean;
+  } = {},
+): PropertyDecorator => {
+  const decs = [
+    Column(type, {
+      default: options.default,
+      unsigned: options.unsigned,
+      ...(type === 'bigint' ? { transformer: new BigintTransformer() } : {}),
+      ...columnDecoratorOptions(options),
+    }),
+    IsInt(),
+    validatorDecorator(options),
+    swaggerDecorator(options, {
+      type: Number,
+      minimum: options.unsigned ? 0 : undefined,
+    }),
+  ];
+  if (options.unsigned) {
+    decs.push(Min(0));
+  }
+  return MergePropertyDecorators(decs);
+};
+
+export const FloatColumn = (
+  type: WithPrecisionColumnType,
+  options: PropertyOptions<string, ColumnNumericOptions> & {
+    unsigned?: boolean;
+  } = {},
+): PropertyDecorator => {
+  const decs = [
+    Column(type, {
+      default: options.default,
+      unsigned: options.unsigned,
+      ...columnDecoratorOptions(options),
+    }),
+    IsNumber(),
+    validatorDecorator(options),
+    swaggerDecorator(options, {
+      type: Number,
+      minimum: options.unsigned ? 0 : undefined,
+    }),
+  ];
+  if (options.unsigned) {
+    decs.push(Min(0));
+  }
+  return MergePropertyDecorators(decs);
+};
+
+export const DateColumn = (
+  options: PropertyOptions<Date> = {},
+): PropertyDecorator => {
+  return MergePropertyDecorators([
+    Column('timestamp', columnDecoratorOptions(options)),
+    IsDate(),
+    validatorDecorator(options),
+    swaggerDecorator(options, { type: Date }),
+  ]);
+};
+
+export const EnumColumn = <T>(
+  targetEnum: Record<string, T>,
+  options: PropertyOptions<T> = {},
+): PropertyDecorator => {
+  return MergePropertyDecorators([
+    Index(),
+    Column('enum', {
+      enum: targetEnum,
+      ...columnDecoratorOptions(options),
+    }),
+    IsEnum(targetEnum),
+    validatorDecorator(options),
+    swaggerDecorator(options, { type: 'enum', enum: targetEnum }),
+  ]);
+};
+
+export const NotColumn = (
+  options: OpenAPIOptions<any> = {},
+): PropertyDecorator =>
+  MergePropertyDecorators([Exclude(), swaggerDecorator(options)]);

src/decorators/restful.ts

+import { Body, Delete, Get, Patch, Post, Query } from '@nestjs/common';
+import {
+  BlankReturnMessageDto,
+  PaginatedReturnMessageDto,
+  ReturnMessageDto,
+} from '../dto';
+import { MergeMethodDecorators } from './merge';
+import { ClassType } from '../utility/insert-field';
+import { TimeBase, TimeBaseFields } from '../bases';
+import {
+  ApiBody,
+  ApiCreatedResponse,
+  ApiNoContentResponse,
+  ApiOkResponse,
+  ApiOperation,
+  ApiParam,
+  OmitType,
+  PartialType,
+} from '@nestjs/swagger';
+import { CreatePipe, GetPipe, UpdatePipe } from './pipes';
+import { OperationObject } from '@nestjs/swagger/dist/interfaces/open-api-spec.interface';
+
+export interface CrudFactoryOptions<T extends TimeBase> {
+  fieldsToOmit?: (keyof T)[];
+}
+
+export class RestfulFactory<T extends TimeBase> {
+  readonly createDto: ClassType<Omit<T, keyof T>>;
+  readonly updateDto: ClassType<Partial<Omit<T, keyof T>>>;
+  readonly entityReturnMessageDto = ReturnMessageDto(this.entityClass);
+  readonly entityArrayReturnMessageDto = PaginatedReturnMessageDto(
+    this.entityClass,
+  );
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  readonly idType: Function;
+
+  constructor(
+    public readonly entityClass: ClassType<T>,
+    private options: CrudFactoryOptions<T> = {},
+  ) {
+    this.createDto = OmitType(this.entityClass, [
+      ...TimeBaseFields,
+      ...(options.fieldsToOmit || []),
+    ]);
+    this.updateDto = PartialType(this.createDto);
+    this.idType = Reflect.getMetadata(
+      'design:type',
+      this.entityClass.prototype,
+      'id',
+    );
+  }
+
+  create(extras: Partial<OperationObject> = {}): MethodDecorator {
+    return MergeMethodDecorators([
+      Post(),
+      ApiOperation({
+        summary: `Create a new ${this.entityClass.name}`,
+        ...extras,
+      }),
+      ApiBody({ type: this.createDto }),
+      ApiCreatedResponse({ type: this.entityReturnMessageDto }),
+    ]);
+  }
+
+  createParam() {
+    return Body(CreatePipe);
+  }
+
+  findOne(extras: Partial<OperationObject> = {}): MethodDecorator {
+    return MergeMethodDecorators([
+      Get(':id'),
+      ApiOperation({
+        summary: `Find a ${this.entityClass.name} by id`,
+        ...extras,
+      }),
+      ApiParam({ name: 'id', type: this.idType, required: true }),
+      ApiOkResponse({ type: this.entityReturnMessageDto }),
+    ]);
+  }
+
+  findAll(extras: Partial<OperationObject> = {}): MethodDecorator {
+    return MergeMethodDecorators([
+      Get(),
+      ApiOperation({ summary: `Find all ${this.entityClass.name}`, ...extras }),
+      ApiOkResponse({ type: this.entityArrayReturnMessageDto }),
+    ]);
+  }
+
+  findAllParam() {
+    return Query(GetPipe);
+  }
+
+  update(extras: Partial<OperationObject> = {}): MethodDecorator {
+    return MergeMethodDecorators([
+      Patch(':id'),
+      ApiOperation({
+        summary: `Update a ${this.entityClass.name} by id`,
+        ...extras,
+      }),
+      ApiParam({ name: 'id', type: this.idType, required: true }),
+      ApiBody({ type: this.updateDto }),
+      ApiOkResponse({ type: BlankReturnMessageDto }),
+    ]);
+  }
+
+  updateParam() {
+    return Body(UpdatePipe);
+  }
+
+  delete(extras: Partial<OperationObject> = {}): MethodDecorator {
+    return MergeMethodDecorators([
+      Delete(':id'),
+      ApiOperation({
+        summary: `Delete a ${this.entityClass.name} by id`,
+        ...extras,
+      }),
+      ApiParam({ name: 'id', type: this.idType, required: true }),
+      ApiNoContentResponse({ type: BlankReturnMessageDto }),
+    ]);
+  }
+}

src/dto/import-entry.ts

+import { ApiProperty } from '@nestjs/swagger';
+import {
+  ClassOrArray,
+  getClassFromClassOrArray,
+  InsertField,
+} from '../utility/insert-field';
+
+export class ImportEntryBaseDto {
+  @ApiProperty({ description: 'Import result', type: String })
+  result: string;
+}
+
+export interface ImportEntry<T> {
+  entry: T;
+  result: string;
+}
+
+export function ImportEntryDto<C extends ClassOrArray>(type: C) {
+  return InsertField(
+    ImportEntryBaseDto,
+    {
+      entry: { type, options: { description: 'Import entry' } },
+    },
+    `${getClassFromClassOrArray(type).name}ImportEntry`,
+  );
+}

src/dto/index.ts

+export * from './page-settings';
+export * from './return-message';

src/dto/page-settings.ts

+import { NotWritable } from '../decorators';
+import { SelectQueryBuilder } from 'typeorm';
+import { IsInt, IsPositive } from 'class-validator';
+import { ApiProperty } from '@nestjs/swagger';
+
+export interface PageSettingsWise {
+  pageCount: number;
+  recordsPerPage: number;
+}
+
+export interface PageSettingsFactory {
+  getActualPageSettings(): PageSettingsWise;
+}
+
+export interface QueryWise<T> {
+  applyQuery(qb: SelectQueryBuilder<T>, entityName: string): void;
+}
+
+export class PageSettingsDto
+  implements PageSettingsWise, PageSettingsFactory, QueryWise<PageSettingsDto>
+{
+  @NotWritable()
+  @IsPositive()
+  @IsInt()
+  @ApiProperty({
+    description: 'The nth page, starting with 1.',
+    required: false,
+    type: Number,
+    minimum: 1,
+  })
+  pageCount: number;
+
+  @NotWritable()
+  @IsPositive()
+  @IsInt()
+  @ApiProperty({
+    description: 'Records per page.',
+    required: false,
+    type: Number,
+    minimum: 1,
+  })
+  recordsPerPage: number;
+
+  getActualPageSettings(): PageSettingsWise {
+    return {
+      pageCount: this.getPageCount(),
+      recordsPerPage: this.getRecordsPerPage(),
+    };
+  }
+
+  getPageCount() {
+    return this.pageCount || 1;
+  }
+
+  getRecordsPerPage() {
+    return this.recordsPerPage || 25;
+  }
+
+  getStartingFrom() {
+    return (this.getPageCount() - 1) * this.getRecordsPerPage();
+  }
+
+  applyQuery(qb: SelectQueryBuilder<PageSettingsDto>, entityName: string) {
+    qb.take(this.getRecordsPerPage()).skip(this.getStartingFrom());
+  }
+}

src/dto/return-message.ts

+import { ApiProperty } from '@nestjs/swagger';
+import { HttpException } from '@nestjs/common';
+import { PageSettingsWise } from './page-settings';
+import {
+  AnyClass,
+  ClassOrArray,
+  getClassFromClassOrArray,
+  InsertField,
+} from '../utility/insert-field';
+
+export interface BlankReturnMessage {
+  statusCode: number;
+  message: string;
+  success: boolean;
+}
+
+export interface ReturnMessage<T> extends BlankReturnMessage {
+  data?: T;
+}
+
+export class BlankReturnMessageDto implements BlankReturnMessage {
+  @ApiProperty({ description: 'Return code', type: Number })
+  statusCode: number;
+  @ApiProperty({ description: 'Return message', type: String })
+  message: string;
+  @ApiProperty({ description: 'Whether success.', type: Boolean })
+  success: boolean;
+  constructor(statusCode: number, message?: string) {
+    this.statusCode = statusCode;
+    this.message = message || 'success';
+    this.success = statusCode < 400;
+  }
+
+  toException() {
+    return new HttpException(this, this.statusCode);
+  }
+}
+
+export class BlankPaginatedReturnMessageDto
+  extends BlankReturnMessageDto
+  implements PageSettingsWise
+{
+  @ApiProperty({ description: 'Total record count.', type: Number })
+  total: number;
+  @ApiProperty({ description: 'Total page count.', type: Number })
+  totalPages: number;
+  @ApiProperty({ description: 'Current page.', type: Number })
+  pageCount: number;
+  @ApiProperty({ description: 'Records per page.', type: Number })
+  recordsPerPage: number;
+  constructor(
+    statusCode: number,
+    message: string,
+    total: number,
+    pageSettings: PageSettingsWise,
+  ) {
+    super(statusCode, message);
+    this.total = total;
+    this.pageCount = pageSettings.pageCount;
+    this.recordsPerPage = pageSettings.recordsPerPage;
+    this.totalPages = Math.ceil(total / pageSettings.recordsPerPage);
+  }
+}
+
+export class GenericReturnMessageDto<T>
+  extends BlankReturnMessageDto
+  implements ReturnMessage<T>
+{
+  data?: T;
+  constructor(statusCode: number, message?: string, data?: T) {
+    super(statusCode, message);
+    this.data = data;
+  }
+}
+
+export function ReturnMessageDto<T extends ClassOrArray>(type: T) {
+  return InsertField(
+    GenericReturnMessageDto,
+    {
+      data: {
+        type,
+        options: {
+          required: false,
+          description: 'Return data.',
+        },
+      },
+    },
+    `${getClassFromClassOrArray(type).name}ReturnMessageDto`,
+  );
+}
+
+export class GenericPaginatedReturnMessageDto<T>
+  extends BlankPaginatedReturnMessageDto
+  implements PageSettingsWise, ReturnMessage<T[]>
+{
+  data: T[];
+  constructor(
+    statusCode: number,
+    message: string,
+    data: T[],
+    total: number,
+    pageSettings: PageSettingsWise,
+  ) {
+    super(statusCode, message, total, pageSettings);
+    this.data = data;
+  }
+}
+
+export function PaginatedReturnMessageDto<T extends AnyClass>(type: T) {
+  return InsertField(
+    GenericPaginatedReturnMessageDto,
+    {
+      data: {
+        type: [type],
+        options: {
+          required: false,
+          description: 'Return data.',
+        },
+      },
+    },
+    `${getClassFromClassOrArray(type).name}PaginatedReturnMessageDto`,
+  );
+}
+
+export class StringReturnMessageDto extends GenericReturnMessageDto<string> {
+  @ApiProperty({ description: 'Return data.', type: String, required: false })
+  data?: string;
+}

src/utility/bigint.ts

+import { ValueTransformer } from 'typeorm';
+
+export class BigintTransformer implements ValueTransformer {
+  from(dbValue) {
+    if (dbValue == null) {
+      return dbValue;
+    }
+    return parseInt(dbValue);
+  }
+  to(entValue): any {
+    return entValue;
+  }
+}

src/utility/index.ts

+export * from './query';

src/utility/insert-field.ts

+import { ApiProperty, ApiPropertyOptions } from '@nestjs/swagger';
+
+export type AnyClass = new (...args: any[]) => any;
+export type ClassOrArray = AnyClass | [AnyClass];
+export type ClassType<T> = new (...args: any[]) => T;
+export type TypeFromClass<T> = T extends new (...args: any[]) => infer U
+  ? U
+  : never;
+export type ParamsFromClass<T> = T extends new (...args: infer U) => any
+  ? U
+  : never;
+export type ParseType<IC extends ClassOrArray> = IC extends [infer U]
+  ? TypeFromClass<U>[]
+  : TypeFromClass<IC>;
+
+export function getClassFromClassOrArray(o: ClassOrArray) {
+  return o instanceof Array ? o[0] : o;
+}
+
+export interface InsertOptions<C extends ClassOrArray = ClassOrArray> {
+  type: C;
+  options?: ApiPropertyOptions;
+}
+
+type TypeFromInsertOptions<O extends InsertOptions> = O extends InsertOptions<
+  infer C
+>
+  ? ParseType<C>
+  : never;
+
+export function InsertField<
+  C extends AnyClass,
+  M extends Record<string, InsertOptions>,
+>(
+  cl: C,
+  map: M,
+  newName?: string,
+): new (...args: ParamsFromClass<C>) => TypeFromClass<C> & {
+  [F in keyof M]: TypeFromInsertOptions<M[F]>;
+} {
+  const extendedCl = class extends cl {};
+  for (const key in map) {
+    ApiProperty({
+      type: map[key].type,
+      ...(map[key].options || {}),
+    })(extendedCl.prototype, key);
+  }
+  Object.defineProperty(cl, 'name', {
+    value: newName || cl.name,
+  });
+  return extendedCl;
+}

src/utility/query.ts

+import { SelectQueryBuilder } from 'typeorm';
+import { TimeBase } from '../bases/time-base';
+
+export function applyQueryProperty<T extends TimeBase>(
+  obj: T,
+  qb: SelectQueryBuilder<T>,
+  entityName: string,
+  ...fields: (keyof T & string)[]
+) {
+  for (const field of fields) {
+    if (obj[field] == null) {
+      continue;
+    }
+    qb.andWhere(`${entityName}.${field} = :${field}`, { [field]: obj[field] });
+  }
+}
+export function applyQueryPropertyLike<T extends TimeBase>(
+  obj: T,
+  qb: SelectQueryBuilder<T>,
+  entityName: string,
+  ...fields: (keyof T & string)[]
+) {
+  for (const field of fields) {
+    if (obj[field] == null) {
+      continue;
+    }
+    qb.andWhere(`${entityName}.${field} like (:${field} || '%')`, {
+      [field]: obj[field],
+    });
+  }
+}
+
+export function applyQueryPropertySearch<T extends TimeBase>(
+  obj: T,
+  qb: SelectQueryBuilder<T>,
+  entityName: string,
+  ...fields: (keyof T & string)[]
+) {
+  for (const field of fields) {
+    if (obj[field] == null) {
+      continue;
+    }
+    qb.andWhere(`${entityName}.${field} like ('%' || :${field} || '%')`, {
+      [field]: obj[field],
+    });
+  }
+}

tests/sample.spec.ts

+describe('Sample test.', () => {
+  it('should pass', () => {
+    expect(true).toBe(true);
+  });
+});

tsconfig.json

+{
+	"compilerOptions": {
+		"outDir": "dist",
+		"module": "commonjs",
+		"target": "es2021",
+		"esModuleInterop": true,
+		"emitDecoratorMetadata": true,
+		"experimentalDecorators": true,
+		"declaration": true,
+		"sourceMap": true
+	},
+	"compileOnSave": true,
+	"allowJs": true,
+	"include": [
+		"*.ts",
+		"src/**/*.ts",
+		"test/**/*.ts",
+		"tests/**/*.ts"
+	]
+}