How to use the @nestjs/graphql.Scalar function in @nestjs/graphql

import { Scalar } from '@nestjs/graphql';
import { Kind, ASTNode } from 'graphql';
import { Types } from 'mongoose';

@Scalar('ObjectId')
export class ObjectIdScalar {
  description = 'MongoDB ObjectId scalar type, sent as 24 byte Hex String';

  parseValue(value: string) {
    return new Types.ObjectId(value); // value from the client
  }

  serialize(value: Types.ObjectId) {
    return value.toHexString(); // value sent to the client
  }

  parseLiteral(ast: ASTNode) {
    if (ast.kind === Kind.STRING) {
      return new Types.ObjectId(ast.value); // ast value is always in string format
    }
    return null;

import { CustomScalar, Scalar } from '@nestjs/graphql';
import { Kind } from 'graphql';

@Scalar('Date', type => Date)
export class DateScalar implements CustomScalar {
  description: string = 'Date custom scalar type';

  parseValue(value: number): Date {
    return new Date(value); // value from the client
  }

  serialize(value: Date): number {
    return value.getTime(); // value sent to the client
  }

  parseLiteral(ast: any): Date {
    if (ast.kind === Kind.INT) {
      return new Date(ast.value);
    }
    return null;

import { CustomScalar, Scalar } from '@nestjs/graphql';
import { Kind } from 'graphql';

@Scalar('Date', type => Date)
export class DateScalar implements CustomScalar {
  description = 'Date custom scalar type';

  parseValue(value: number): Date {
    return new Date(value); // value from the client
  }

  serialize(value: Date): number {
    return value.getTime(); // value sent to the client
  }

  parseLiteral(ast: any): Date {
    if (ast.kind === Kind.INT) {
      return new Date(ast.value);
    }
    return null;

import { CustomScalar, Scalar } from '@nestjs/graphql';
import { Kind } from 'graphql';

@Scalar('Date')
export class DateScalar implements CustomScalar {
	description = 'Date custom scalar type';

	parseValue(value: number): Date {
	  return new Date(value); // value from the client
	}

	serialize(value: Date): number {
	  return value.getTime(); // value sent to the client
	}

	parseLiteral(ast: any): Date {
	  if (ast.kind === Kind.INT) {
	    return new Date(ast.value);
	  }
	  return null;

import { Scalar } from '@nestjs/graphql';
import { Kind } from 'graphql';

@Scalar('DateTime')
export class DateTimeScaler {
  description = 'DateTime custom scalar type';

  parseValue(value) {
    return new Date(value); // value from the client
  }

  serialize(value) {
    return value.getTime(); // value sent to the client
  }

  parseLiteral(ast) {
    if (ast.kind === Kind.INT) {
      return parseInt(ast.value, 10); // ast value is always in string format
    }
    return null;

import { CustomScalar, Scalar } from '@nestjs/graphql';
import { Kind } from 'graphql';

@Scalar('Date', type => Date)
export class DateScalar implements CustomScalar {
  description = 'Date custom scalar type';

  parseValue(value: string): Date {
    return new Date(value); // value from the client
  }

  serialize(value: Date): string {
    return new Date(value).toISOString(); // value sent to the client
  }

  parseLiteral(ast: any): Date {
    if (ast.kind === Kind.INT) {
      return new Date(ast.value);
    }
    return null;

import {Scalar} from '@nestjs/graphql';
import {Kind} from 'graphql';
import {DateTime} from 'luxon';

@Scalar('Date')
export class DateScalar {
	description = 'Date custom scalar type';

	parseValue(value) {
		return new Date(value); // value from the client
	}

	serialize(value: Date|DateTime) {
		if (value instanceof DateTime) {
			return value.toJSON();
		}
		return value.toISOString(); // value sent to the client
	}

	parseLiteral(ast) {
		if (ast.kind === Kind.STRING) {

import { CustomScalar, Scalar } from '@nestjs/graphql'
import { Kind } from 'graphql'

@Scalar('Date', type => Date)
export class DateScalar implements CustomScalar {
	description = 'Date custom scalar type'

	parseValue(value: number): Date {
		return new Date(value) // value from the client
	}

	serialize(value: Date): number {
		return value.getTime() // value sent to the client
	}

	parseLiteral(ast: any): Date {
		if (ast.kind === Kind.INT) {
			return new Date(ast.value)
		}
		return null

import { CustomScalar, Scalar } from '@nestjs/graphql';
import { Kind } from 'graphql';

@Scalar('Date')
export class DateScalar implements CustomScalar {
  description = 'Date custom scalar type';

  parseValue(value: number): Date {
    return new Date(value); // value from the client
  }

  serialize(value: Date): number {
    return value.getTime(); // value sent to the client
  }

  parseLiteral(ast: any): Date {
    if (ast.kind === Kind.INT) {
      return new Date(ast.value);
    }
    return null;

import { CustomScalar, Scalar } from '@nestjs/graphql';
import { Kind } from 'graphql';

@Scalar('Date', type => Date)
export class DateScalar implements CustomScalar {
  description: string = 'Date custom scalar type';

  parseValue(value: number): Date {
    return new Date(value); // value from the client
  }

  serialize(value: Date): number {
    return value.getTime(); // value sent to the client
  }

  parseLiteral(ast: any): Date {
    if (ast.kind === Kind.INT) {
      return new Date(ast.value);
    }
    return null;