onebeyond/swagger-endpoint-validator

const debug = require('debug')('swagger-endpoint-validator:openapi-spec');
const fs = require('fs');
const jsYaml = require('js-yaml');
const swaggerJSDoc = require('swagger-jsdoc');
const expressJSDocSwagger = require('express-jsdoc-swagger');
const Enforcer = require('openapi-enforcer');

const { SUPPORTED_FORMATS } = require('./constants');
const errorFactory = require('./errors');

const SwaggerValidatorError = errorFactory('swagger_validator');

/**
 * Generates the OpenAPI specification document from the express application documentation.
 * @param {Object} app - Express application object.
 * @param {Object} options - Configuration options.
 * @returns {{ spec: Object, openapi: Object }} OpenAPI specification.
 */
const generate = async (app, options) => {
    const specByFormat = {
        [SUPPORTED_FORMATS.JSDOC]: async formatOptions => {
            const instance = expressJSDocSwagger(app)(formatOptions);

            return new Promise((resolve, reject) => {
                instance.on('finish', resolve);

                instance.on('error', reject);
            });
        },
        [SUPPORTED_FORMATS.YAML]: formatOptions => jsYaml.load(fs.readFileSync(formatOptions.file, 'utf-8')),
        [SUPPORTED_FORMATS.YAML_JSDOC]: formatOptions => swaggerJSDoc(formatOptions),
    };

    try {
        debug('Merging documents to generate specification...');
        const doc = await specByFormat[options.format](options[options.format]);
        debug(`Specification generated!: ${JSON.stringify(doc)}`);

        debug('Dereferencing and validating specification...');
        const openapi = await Enforcer(doc);
        debug('Specification dereferenced and validated!');

        return { doc, openapi };
    } catch (error) {
        throw SwaggerValidatorError(`Wrong options for ${options.format}: ${error.message}`);
    }
};

module.exports = {
    generate,
};