Cypress Swagger Validation Plugin

Validate your request responses against Swagger JSON Endpoints. AKA Contract Testing.

Do you use Cypress to perform API endpoint testing? Do you have Swagger/Openapi v3 schema? This is the plugin for you.

See the example swagger files to see how the usage below works with it.

Your swagger doc will need endpoints with content schema defined.

Cypress Installation

yarn add @jc21/cypress-swagger-validation

Then in your cypress Plugins file:

const {SwaggerValidation} = require('@jc21/cypress-swagger-validation');

module.exports = (on, config) => {
    // ...
    on('task', SwaggerValidation(config));
    // ...
    return config;
};

Cypress Usage

describe('Basic API checks', () => {
    it('Should be a valid swagger schema', function () {
        cy.task('validateSwaggerFile', {
            file: './testing/swagger.json',  // optional path or full URL, see below
        }).should('equal', null);
    });

    it('Should return a valid health payload', function () {
        cy.request('/healthz').then($response => {
            // Check the swagger schema:
            cy.task('validateSwaggerSchema', {
                file:           './testing/swagger.json',  // optional path or full URL, see below
                endpoint:       '/healthz',
                method:         'get',
                statusCode:     200,
                responseSchema: $response.body,
                verbose:        true,                      // optional, default: false
            }).should('equal', null);
        });
    });
});

The swagger file

This can either be a file on disk or a URL.

When using a file on disk and due to the fact that this plugin runs on the Cypress Backend, the location of the file must be defined as either the full path on disk or relative path to the running of the cypress command.

You can define the swagger file location either with an environment variable which can apply to all tests:

config.env.swaggerFile

or within each individial test using the options below.

Options

validateSwaggerFile

Option	Description	Optional	Default
file	The location of the swagger file to use for contract testing	true	config.env.swaggerFile

validateSwaggerSchema

Option	Description	Optional	Default
file	The location of the swagger file to use for contract testing	true	config.env.swaggerFile
endpoint	The name of the swagger endpoint to check
method	The request method of the endpoint
statuscode	The http status code beneath the method
responseSchema	The payload of the API response to validate
verbose	Console.log more info when validation fails	true	false

Compiling Source

yarn install
yarn build
yarn test