Sample to chain async calls

index.ts

import seeder from './seeder';

seeder({ model: 'User' })
	.clear()
	.seed()
	.fail()
	.clear()
	.catch((err:Error) => {
		console.log( err.stack )
		console.error('chain catch');
	});

seeder.ts

import * as mongoose from 'mongoose';

const seeder = (config: any, promise: Promise<any> = Promise.resolve()) => {

	const _exec = (f: () => any) => {
		return seeder(config, promise.then(f).catch((err) => {
			return Promise.reject(err);
		}));
	}

	return {
		clear: () => {
			return _exec(() => {
				const model = require(`../models/${config.model.toLowerCase()}.model`)[config.model];
				return model.remove().exec();
			});
		},

		seed: () => {
			return _exec(() => {
				const model = require(`../models/${config.model.toLowerCase()}.model`)[config.model];
				const entities = require(`./${config.model.toLowerCase()}s`).default;
				return model.create(entities);
			});
		},

		fail: () => {
			return _exec(() => {
				return Promise.reject(new Error('reason!!!'))
			})
		},

		catch: (f: any) => {
			promise.catch(f);
		}
	};
}

export default seeder;

users.ts

export default [{
	firstName: 'Some',
	lastName: 'Person',
	cv: {
		description: 'nested model'
	}
}];