mongrr-schema

Typescript MongoDB Schema Generator

Motivation

Generate and keep your MongoDB Schema Validation up-to-date based on your types!

Types are/should be always up-to-date in order to enable proper Typescript usage.
This library' aim is to automate the mundane task of keeping the MongoDB Schema Validation in sync with your API or various services types.

Installing

npm install --save mongrr-schema

Usage

Basic

Given a target file

// ./lib/models/User.ts
export default class User {
    id: number;

    phone?: Array<string>;

    address: Address;

    active: boolean;
}

class Address {
    street: string;

    county: string;

    flatNumber?: number;
}

Simple generation e.g.

// index.ts
import { Generator } from 'mongrr-schema';

async function main() {

    await Generator.generate({
        files: ['./lib/models/User.ts'],
        callerBaseDir: __dirname,
        connectionString: 'mongodb://localhost:27017', // actual mongodb conn string
        databaseName: 'myExampleDb' // target db to use
    });

}

main().catch(console.error);

Runtime without access to /src type files

Using tparserr to generate type description file

tparserr can be installed as dev and attached to build

npm install --save-dev tparserr

with e.g. npm script attached to the build

"build:types": "tparserr generate -f=./src/lib/models/User.ts -o=./schema.json"

can simply

await Generator.generateForTypes({
    connectionString: 'mongodb://localhost:27017', // actual mongodb conn string
    databaseName: databaseName // target db to use
}, './schema.json');

Note: to enable decorators and other options - see https://github.com/razmat145/tparserr#configuration

"build:types": "tparserr generate -f=./src/lib/models/User.ts -o=./schema.json" --includeOnlyExports=true --enableDecorators=true

Decorators

Decorators can be used to influence the MongoDB schema generation by applying various modifiers or by outright changing the behaviour completely.

import {
    CollectionName,
    Index,
    CompoundIndex,
    Int,
    Double,
    Minimum,
    MinLength,
    MaxLength,
    Description,
    MinItems,
    UniqueItems
} from 'mongrr-schema'

@Description('My User entity XYZ')
@CompoundIndex(
    ['name'],
    ['address', 'desc']
)
@CollectionName('MyUsers')
export class User {
    id: string;

    @Index()
    @MinLength(6)
    @Description(`Name of the user, it's required and has minimum 6 chars`)
    name: string;

    @MinItems(1)
    @UniqueItems(true)
    phone: Array<string>;

    @MaxLength(50)
    @Description(`Adress of the user, it's required and has a maximum of 50 chars`)
    address: string;

    @Index('desc')
    active: boolean;

    @Int()
    @Minimum(18)
    @Description(`Age of the user, it's required and must be over 18`)
    age: number;

    @Double()
    balance: number;
}

With created schema

And created indexes

Supported Decorators

Decorator naming aims to stay as close to MongoDB docs/namings as possible (where possible) - the only exception is them being @CapitalCamelCased

Generic Decorators

• @Description - attaches description metadata to classes and properties

Class Decorators

• @CollectionName(name: string) - using the specified name when creating/updating the collection schema
• @CompoundIndex(..args: Array<[propertyPath, 'asc' | 'desc']>) - creating a compound index on the [path, direction] provided arguments

Property Decorators

Generic

• @Index() - creating an index on decorated property

Number Type

• @Double() - modifier that marks the number as a double BSON type
• @Long() - modifier that marks the number as a long BSON type
• @Int() - modifier that marks the number as a int BSON type
• @Decimal() - modifier that marks the number as a decimal BSON type
• @Minimum(min: number) - modifier that enforces the min value
• @Maximum(max: number) - modifiers that enforces the max value

String Type

• @MinLength(minLength: number) - modifier that enforces the minLength value
• @MaxLength(maxLength: number) - modifiers that enforces the maxLength value

Array Type

• @MinItems(minItems: number) - modifier that enforces the length of the array to the specified minItems value
• @MaxItems(maxItems: number) - modifier that enforces the length of the array to the specified maxItems value
• @UniqueItems(hasUniqueItems: boolean) - modifier that enforces array item uniqueness

Configuration

FilePath opts are inherited by tparserr dependency - see https://github.com/razmat145/tparserr#configuration for more info

type TParserOptsPaths = Pick<IParserOpts,
    'files'
    | 'useRelativePaths'
    | 'callerBaseDir'
    | 'targetDir'
    | 'includeOnlyExports'
    | 'includeNestedClassNames'
    | 'enableDecorators'
>;

interface IGeneratorOpts extends TParserOptsPaths {
    // requires either connection details
    connectionString?: string; // mongodb connection string

    databaseName?: string; // database name to create/use

    // OR
    mongoDb?: Db; // MongoDB (database ref) Db type
}

License

This library is licensed under the Apache 2.0 License