npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

jest-json-schema

v6.1.0

Published

JSON schema matcher for jest

Downloads

258,971

Readme

jest-json-schema

npm version Build Status Mentioned in Awesome Jest

JSON schema matcher for jest

Want to get paid for your contributions to jest-json-schema? Send your resume to [email protected]

Matchers included

toMatchSchema(schema)

Validates that an object matches the given JSON schema

it('validates my json', () => {
  const schema = {
    properties: {
      hello: { type: 'string' },
    },
    required: ['hello'],
  };
  expect({ hello: 'world' }).toMatchSchema(schema);
});

Installation

$ npm install --save-dev jest-json-schema

Usage

In any test file:

import { matchers } from 'jest-json-schema';
expect.extend(matchers);

Or if you want it available for all test files then set it up the same way in a test framework script file

You can pass Ajv options using matchersWithOptions and passing it your options object. The only option passed by default is allErrors: true.

import { matchersWithOptions } from 'jest-json-schema';

const formats = {
  bcp47: /^[a-z]{2}-[A-Z]{2}$/,
}

expect.extend(matchersWithOptions({ formats }));

Additionally you can also use a callback to further configure and extend the Ajv instance used by the matchers:

import ajvKeywords from 'ajv-keywords';
import { matchersWithOptions } from 'jest-json-schema';

const formats = {
  bcp47: /^[a-z]{2}-[A-Z]{2}$/,
}

expect.extend(matchersWithOptions({ formats }, (ajv) => {
  // This uses the `ajv-keywords` library to add pre-made
  // custom keywords to the Ajv instance.
  ajvKeywords(ajv, ['typeof', 'instanceof']);
}));

You can also customize the Ajv class with the AjvClass option:

import Ajv2020 from 'ajv/dist/2020'
import { matchersWithOptions } from 'jest-json-schema';

expect.extend(matchersWithOptions({ AjvClass: Ajv2020 }));

Verbose errors

Ajv supports a verbose option flag which enables more information about individual errors. This extra information can mean that we can output to Jest more meaningful errors that can help the development process:

const { matchersWithOptions } = require('jest-json-schema');

expect.extend(matchersWithOptions({
  verbose: true
}));

test('check that property errors are outputted', () => {
  const schema = {
    $id: 'testSchema',
    type: 'object',
    properties: {
      name: {
        type: 'string',
      },
      dob: {
        type: 'string',
        format: 'date',
      },
    },
  };

  const invalidData = {
    name: null,
    dob: '02-29-2000',
  };

  expect(() => {
    expect(invalidData).toMatchSchema(schema)
  }).toThrowErrorMatchingInlineSnapshot(`
"expect(received).toMatchSchema(schema)

Received:
  .name should be string
    Received: <null>
    Path: testSchema#/properties/name/type
  .dob should match format \\"date\\"
    Received: <string> 02-29-2000
    Path: testSchema#/properties/dob/format
"
`);
});

Example using multiple schema files

If you organise your schemas into separate files and use refs which point to the various different schemas, it will be important to include those dependent schema files when extending Jest's expect handler, using the matchersWithOptions interface:

schemaA.json

{
  "$id": "schemaA",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "description": "Example of a definition schema.",
  "definitions": {
    "testA": {
      "type": "number",
      "const": 1
    },
    "testB": {
      "type": ["null", "string"]
    }
  }
}

schemaB.json

{
  "$id": "schemaB",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "description": "Example of a schema that references another schema.",
  "$ref": "schemaA#/definitions/testB"
}

schemaA.test.js

const { matchersWithOptions } = require('jest-json-schema');

// Local schema files are imported like normal. If you use TypeScript you
// will need to ensure `--resolveJsonModule` is enabled.
const schemaA = require('./schemaA.json');
const schemaB = require('./schemaB.json');

expect.extend(matchersWithOptions({
  // Loading in a schema which is comprised only of definitions,
  // which means specific test schemas need to be created.
  // This is good for testing specific conditions for definition schemas.
  schemas: [schemaA]
});

test('schemaA is valid', () => {
  expect(schemaA).toBeValidSchema();
});

test('using schemaA to build a test schema to test a specific definition', () => {
  // This is a test schema which references a definition in one of the
  // pre-loaded schemas. This can allow us to write tests for specific
  // definitions.
  const testSchema = {
    $ref: 'schemaA#/definitions/testA'
  };

  expect(testSchema).toBeValidSchema();

  // Valid
  expect(1).toMatchSchema(testSchema);

  // This example runs through a number of values that we know don't match
  // the schema, ensuring that any future changes to the schema will require
  // the test to be updated.
  ['1', true, false, null, [], {}].forEach(value => {
     expect(value).not.toMatchSchema(testSchema);
  });
});

test('using schemaB which already references a definition in schemaA', () => {
  expect(schemaB).toBeValidSchema();

  // Valid
  ['', '1', null].forEach(value => {
    expect(value).toMatchSchema(schemaB);
  });

  // Invalid
  ['1', true, false, [], {}].forEach(value => {
     expect(value).not.toMatchSchema(schemaB);
  });
});

TypeScript support

If you would like to use jest-json-schema library in your TypeScript project, remember to install type definitions from @types/jest-json-schema package.

npm install --save-dev @types/jest-json-schema

Or if yarn is your package manager of choice:

yarn add @types/jest-json-schema --dev

Contributing

We welcome Your interest in the American Express Open Source Community on Github. Any Contributor to any Open Source Project managed by the American Express Open Source Community must accept and sign an Agreement indicating agreement to the terms below. Except for the rights granted in this Agreement to American Express and to recipients of software distributed by American Express, You reserve all right, title, and interest, if any, in and to Your Contributions. Please fill out the Agreement.

Please feel free to open pull requests and see CONTRIBUTING.md to learn how to get started contributing.

License

Any contributions made under this project will be governed by the Apache License 2.0.

Code of Conduct

This project adheres to the American Express Community Guidelines. By participating, you are expected to honor these guidelines.