mongoose-schema-jsonschema

The module allows to create json schema from Mongoose schema by adding jsonSchema method to mongoose.Schema, mongoose.Model and mongoose.Query classes

Contents

• mongoose-schema-jsonschema
• Contents
• Installation
• Schema Build Configuration
• Samples
• Validation tools
• Specifications
  • mongoose.Schema.prototype.jsonSchema
  • mongoose.Model.jsonSchema
  • mongoose.Query.prototype.jsonSchema
• Custom Schema Types Support
• Releases
• Supported versions

---

Installation

npm install mongoose-schema-jsonschema

Schema Build Configuration

Since v1.4.0 it is able to configure how jsonSchema() works.

To do that package was extended with config function.

const config = require('mongoose-schema-jsonschema/config');

config({
  // ... options go here
});

Currently there are two options that affects build process:

• forceRebuild: boolean -- mongoose-schema-jsonschema caches json schemas built for mongoose schemas. That means we cannot built updated jsonSchema after some updates were made in the mongoose schema that already has jsonSchema. To resolve this issue the forceRebuild was added (see sample bellow)

• fieldOptionsMapping: { [key: string]: string } | Array<string|[string, string]> - allows to specify how to convert some custom options specified in the mongoose field definition.

const mongoose = require('mongoose-schema-jsonschema')();
const config = require('mongoose-schema-jsonschema/config');

const { Schema } = mongoose;

const BookSchema = new Schema({
  title: { type: String, required: true, notes: 'Book Title' },
  year: Number,
  author: { type: String, required: true },
});

const fieldOptionsMapping = {
  notes: 'x-notes',
};

config({ fieldOptionsMapping });
console.dir(BookSchema.jsonSchema(), { depth: null });

config({ fieldOptionsMapping: [], forceRebuild: true }); // reset
console.dir(BookSchema.jsonSchema(), { depth: null });

Output:

{
  type: 'object',
  properties: {
    title: { type: 'string', 'x-notes': 'Book Title' },
    year: { type: 'number' },
    author: { type: 'string' },
    _id: { type: 'string', pattern: '^[0-9a-fA-F]{24}$' }
  },
  required: [ 'title', 'author' ]
}
{
  type: 'object',
  properties: {
    title: { type: 'string' },
    year: { type: 'number' },
    author: { type: 'string' },
    _id: { type: 'string', pattern: '^[0-9a-fA-F]{24}$' }
  },
  required: [ 'title', 'author' ]
}

Samples

Let's build json schema from simple mongoose schema

const mongoose = require('mongoose');
require('mongoose-schema-jsonschema')(mongoose);

const Schema = mongoose.Schema;

const BookSchema = new Schema({
  title: { type: String, required: true },
  year: Number,
  author: { type: String, required: true },
});

const jsonSchema = BookSchema.jsonSchema();

console.dir(jsonSchema, { depth: null });

Output:

{
  type: 'object',
  properties: {
    title: { type: 'string' },
    year: { type: 'number' },
    author: { type: 'string' },
    _id: { type: 'string', pattern: '^[0-9a-fA-F]{24}$' }
   },
  required: [ 'title', 'author' ]
}

The mongoose.Model.jsonSchema method allows to build json schema considering the field selection and population

const mongoose = require('mongoose');
require('mongoose-schema-jsonschema')(mongoose);

const Schema = mongoose.Schema;

const BookSchema = new Schema({
  title: { type: String, required: true },
  year: Number,
  author: { type: Schema.Types.ObjectId, required: true, ref: 'Person' }
});

const PersonSchema = new Schema({
  firstName: { type: String, required: true },
  lastName: { type: String, required: true },
  dateOfBirth: Date
});

const Book = mongoose.model('Book', BookSchema);
const Person = mongoose.model('Person', PersonSchema)

console.dir(Book.jsonSchema('title year'), { depth: null });
console.dir(Book.jsonSchema('', 'author'), { depth: null });

Output:

{
  title: 'Book',
  type: 'object',
  properties: {
    title: { type: 'string'  },
    year: { type: 'number'  },
    _id: { type: 'string', pattern: '^[0-9a-fA-F]{24}$' }
  }
}
{
  title: 'Book',
  type: 'object',
  properties: {
    title: { type: 'string'  },
    year: { type: 'number'  },
    author: {
      title: 'Person',
      type: 'object',
      properties: {
        firstName: { type: 'string'  },
        lastName: { type: 'string'  },
        dateOfBirth: { type: 'string', format: 'date-time'  },
        _id: { type: 'string', pattern: '^[0-9a-fA-F]{24}$'  },
        __v: { type: 'number' }
       },
      required: [ 'firstName', 'lastName' ],
      'x-ref': 'Person',
      description: 'Refers to Person'
     },
    _id: { type: 'string', pattern: '^[0-9a-fA-F]{24}$'  },
    __v: { type: 'number' }
   },
  required: [ 'title', 'author' ]
}

const mongoose = require('mongoose');
const extendMongoose = require('mongoose-schema-jsonschema');

extendMongoose(mongoose);

const { Schema } = mongoose;

const BookSchema = new Schema({
  title: { type: String, required: true  },
  year: Number,
  author: { type: Schema.Types.ObjectId, required: true, ref: 'Person' }
});

const Book = mongoose.model('Book', BookSchema);
const Q = Book.find().select('title').limit(5);


console.dir(Q.jsonSchema(), { depth: null });

Output:

{
  title: 'List of books',
  type: 'array',
  items: {
    type: 'object',
    properties: {
      title: { type: 'string'  },
      _id: { type: 'string', pattern: '^[0-9a-fA-F]{24}$' }
    }
   },
  maxItems: 5
}

Validation tools

Created by mongoose-schema-jsonschema json-schema's could be used for document validation with:

• ajv
• jsonschema

Specifications

mongoose.Schema.prototype.jsonSchema

Builds the json schema based on the Mongoose schema. if schema has been already built the method returns new deep copy

Method considers the schema.options.toJSON.virtuals to included the virtual paths (without detailed description)

Declaration:

function schema_jsonSchema(name) { ... }

Parameters:

• name: String - Name of the object
• Returns Object - json schema

mongoose.Model.jsonSchema

Builds json schema for model considering the selection and population

if fields specified the method removes required constraints

Declaration:

function model_jsonSchema(fields, populate) { ... }

Parameters:

• fields: String|Array|Object - mongoose selection object
• populate: String|Object - mongoose population options
• Returns Object - json schema

mongoose.Query.prototype.jsonSchema

Builds json schema considering the query type and query options. The method returns the schema for array if query type is find and the schema for single document if query type is findOne or findOneAnd*.

In case when the method returns schema for array the collection name is used to form title of the resulting schema. In findOne* case the title is the name of the appropriate model.

Declaration:

javascript function query_jsonSchema() { ... }

Parameters:

• Returns Object - json schema

Custom Schema Types Support

If you use custom Schema Types you should define the jsonSchema method for your type-class(es).

The base functionality is accessible from your code by calling base-class methods:

newSchemaType.prototype.jsonSchema = function() {
  // Simple types (strings, numbers, bools):
  const jsonSchema = mongoose.SchemaType.prototype.jsonSchema.call(this);

  // Date:
  const jsonSchema = Types.Date.prototype.jsonSchema.call(this);

  // ObjectId
  const jsonSchema = Types.ObjectId.prototype.jsonSchema.call(this);

  // for Array (or DocumentArray)
  const jsonSchema = Types.Array.prototype.jsonSchema.call(this);

  // for Embedded documents
  const jsonSchema = Types.Embedded.prototype.jsonSchema.call(this);

  // for Mixed documents:
  const jsonSchema = Types.Mixed.prototype.jsonSchema.call(this);

  /*
   *
   * Place your code instead of this comment
   *
   */

   return jsonSchema;
}

Releases

• version 1.0 - Basic functionality
• version 1.1 - Mongoose.Query support implemented
• version 1.1.5 - uuid issue fixed, ajv compliance verified
• version 1.1.8 - Schema.Types.Mixed issue fixed
• version 1.1.9 - readonly settings support added
• version 1.1.11 - required issue fixed issue#2
• version 1.1.12 - mixed-type fields description and title support added (fix for issue: issue#3)
• version 1.1.15 - support for mongoose@5.x ensured issue#8
• version 1.3.0
• nullable types support (as union: [type, 'null'])
• examples option support issue#14
• support for fields dynamicly marked as required issue#16
• Node support restricted to 8.x, 9.x, 10.x, 12.x
• Mongoose support restricted to 5.x
• Development:
  • migrated from mocha + istanbul to jest
  • added eslint
• version 1.3.1 - support minlenght and maxlength issue#21
• version 1.4.0 - broken - schema build configurations (forceRebuild and fieldOptionsMapping)
• version 1.4.2 - fix for broken version 1.4.0 issue#22
• version 1.4.4 - fix for field constraints issue#25
• version 2.0.0 - Support for mongoose@6.x.x. Node v8.x.x, v9.x.x are no longer supported (use v1.4.7 of the lib)
• version 2.1.0 - Support for mongoose@7.x.x and Node v14.x, v16.x, v18.x
• version 2.2.0 - Support for mongoose@8.x.x and Node v20.x. Node v14.x is no longer supported (use v2.1.0 of the lib)
• version 2.2.1 - fix for required fields: if required is a function, it is not considered as required field
• version 3.0.0 - breaking changes on Array with required: the minItems constraint is removed from JSON schema
• version 4.0.0
• Node support shifted to 18+
• Mongoose support restricted to 6+

Supported versions

• node.js: 18.x, 20.x, 22.x, 24.x
• mongoose: 6.x, 7.x, 8.x, 9.x