onebeyond/swagger-endpoint-validator

const debug = require('debug')('swagger-endpoint-validator:validator');
const OpenApiValidator = require('express-openapi-validator');

const errorFactory = require('./errors');

const SwaggerValidatorError = errorFactory('swagger_validator');

let openAPISpec = null;

/**
 * Initializes the OpenAPI validator.
 * @param {Object} app - Express application object.
 * @param {Object} options - Configuration options.
 * @param {Object} spec - OpenAPI specification, extracted from the documentation.
 * @param {Object} spec.doc - JSON object describing the extracted OpenAPI specification.
 * @param {Object} spec.openapi - OpenAPI specification extracted from openapi-enforcer.
 * @see https://github.com/cdimascio/express-openapi-validator
 */
const init = async (app, options, spec) => {
    debug('Initializing OpenAPI validator...');

    const {
        $refParser,
        coerceTypes,
        fileUploader,
        ignorePaths,
        operationHandlers,
        unknownFormats,
        validateFormats,
        validateRequests,
        validateResponses,
        validateSecurity,
    } = options;

    app.use(
        OpenApiValidator.middleware({
            apiSpec: spec.doc,
            $refParser,
            coerceTypes,
            fileUploader,
            ignorePaths,
            operationHandlers,
            unknownFormats,
            validateFormats,
            validateRequests,
            validateResponses,
            validateSecurity,
        }),
    );

    openAPISpec = spec.openapi;

    debug('OpenAPI validator initialized!');
};

/**
 * Validates an object using an schema inside the OpenAPI specification.
 * @param {Object} body - Information to do the validation.
 * @param {string} body.endpoint - path to be validated.
 * @param {object} body.fixture - data to be validated against the schema.
 * @param {string} body.method - method inside the path to be validated.
 * @param {boolean} [body.input=false] - true to validate the request schema and false to validate the response schema.
 */
const validateSchema = body => {
    if (!openAPISpec) {
        throw SwaggerValidatorError('You need to initialize the validator first!');
    }

    debug('Validating data againt schema...');

    const {
        endpoint,
        fixture,
        request,
        method,
    } = body;

    if (!endpoint) {
        throw SwaggerValidatorError('Required \'endpoint\' missing in requestBody', 400);
    }
    if (!method) {
        throw SwaggerValidatorError('Required \'method\' missing in requestBody', 400);
    }
    if (!fixture) {
        throw SwaggerValidatorError('Required \'fixture\' missing in requestBody', 400);
    }

    let result;
    if (request) {
        result = openAPISpec.request({
            method,
            path: endpoint,
            body: fixture,
        });
    } else {
        const path = openAPISpec.paths[endpoint];
        if (!path) {
            throw SwaggerValidatorError(`endpoint '${endpoint}' not found in the specification`);
        }
        const operation = path[method.toLowerCase()];
        if (!operation) {
            throw SwaggerValidatorError(`method '${method.toLowerCase()}' for endpoint '${endpoint}' not found in the specification`);
        }
        result = operation.response(200, fixture);
    }

    debug(`Validation result: ${JSON.stringify(result)}`);
    return result;
};

module.exports = {
    init,
    validateSchema,
};