graphql-validity/src/validation.ts

Make business logic validation easy on the graphql side without adding any declarations or modifications to the existing graphql schema.

/*!
 * The MIT License (MIT)
 *
 * Copyright (c) 2017 Vlad Martynenko <vladimir.martynenko.work@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import { PROFILING_DEBOUNCE_TIME } from "./magic-values";
import {
    ValidityConfig
} from "./helpers";

/* An object which stores all validator functions
    required to be executed during graphql request */
export const FieldValidationDefinitions: any = {};

/**
 * Builds errors array, using validation results
 *
 * @param validity - an object injected to request at the beginning of the http call
 * @param data - result of graphql call
 */
export function getResponseValidationResults(validity: any, data: any) {
    if (data.errors || (validity && validity.___validationResults && validity.___validationResults.length)) {
        const originalErrors = data.errors || [];
        data.errors =
            (Array.isArray(originalErrors) ? originalErrors : [originalErrors])
                .map((err) => {
                    return processError(err, validity.config);
                })
                .concat(
                    validity.___validationResults.map(
                        (error: Error) => {
                            return {
                                message: processError(error, validity.config).message
                            };
                        })
                );
    }
}

/**
 * Masks errors if requests, other way returns original graphql error object
 *
 * @param error - graphql error object
 * @param {ValidityConfig} config - config - setup options for the wrapper function
 * @returns {any} - graphql error object
 */
function processError(error: any, config: ValidityConfig) {
    if (error.name === 'ValidityError' || error.message.indexOf('_Validity_') >= 0) {
        error.message = error.message.slice(10);
        return error;
    }

    if (config && config.wrapErrors) {
        if (config.unhandledErrorWrapper) {
            const result = config.unhandledErrorWrapper(error);
            return {
                message: result.message,
                path: error.path,
                location: error.location
            };
        }
    }

    return error;
}

/**
 * Returns lists of graphql validation messages arrays from request object
 *
 * @param request - express request object
 * @returns {validationResults: any[]} - list of validation result messages
 */
export function getValidationResults(validity: any) {
    let validationResults = validity.___validationResults;

    if (!validationResults) {
        validity.___validationResults = [];
        validationResults = validity.___validationResults;
    }

    return validationResults;
}

/**
 * Return list of local and global validators
 *
 * @param field - field which will be validated
 * @param {string} parentTypeName - name of the parent object where field belongs to
 * @param validity - an object injected to request at the beginning of the http call
 *
 * @returns {validators: any[]}
 * - list of local and global validator functions
 */
export function getValidators(
    field: any,
    parentTypeName: string,
    validity: any
) {
    let validators =
        (
            FieldValidationDefinitions['*']
            || []
        ).concat
        (
            FieldValidationDefinitions[field.type]
            || []
        ).concat
        (
            FieldValidationDefinitions[parentTypeName + ':' + field.name]
            || []
        );

    if (!validity.___globalValidationResultsCaptured) {
        validity.___globalValidationResultsCaptured = true;
        validators = validators.concat(FieldValidationDefinitions['$'] || []);
    }

    return validators;
}

/**
 * Modifies express response with validation results
 *
 * @param req - express request
 * @param data - response original data
 * @param profilingResultHandler - profiling function
 *
 * @returns {string} - response modified data
 */
export function applyValidation(
    req: any,
    data: any,
    profilingResultHandler: Function
) {
    let result = JSON.parse(data);

    const validity = req.__graphQLValidity;
    getResponseValidationResults(validity, result);

    setTimeout(() => {
        if (validity && validity.___profilingData) {
            const profilingData = validity.___profilingData;
            profilingResultHandler(profilingData, req.__graphQLValidityRequestId);
        }
    }, PROFILING_DEBOUNCE_TIME);

    return JSON.stringify(result);
}