next-middle-api-query-parser

This is a middleware for next-middle-api.

It allows you to do the following

• get parsed query params in your handler
• apply validation for your query params
  • apply simple validations
  • apply a complex validation if there are no simple validation errors
• get a type based on your params definition
• create a definition for custom type

define a route with in built data types

//  host/api/hello?limit=20&query=test&startFrom=2022-05-21T05:54:34.523Z&ids=2&ids=3
import { createHandlers, PerRequestContext } from 'next-middle-api';
import {
  createOptionalType,
  createQueryParamsMiddleWare,
  dateType,
  intType,
  stringType,
  TypeSafeParams,
  PARSED_QUERY_PARAMS,
  QUERY_PARAM_PARSER_ERRORS,
  QUERY_PARAM_VALIDATION_ERROR
} from '../../../next-middle-api-query-parser';
import { createArrayType, ValidationErrors } from 'next-middle-api-query-parser';

// define your query params
const params = {
  limit: intType,
  query: stringType,
  // use factories to chain types to handle arrays and/or optional type
  startFrom: createOptionalType(dateType),
  ids: createArrayType(intType)
};

// generate type safe definitions from your param definition
type ParamsType = typeof params;
type MyQueryParams = TypeSafeParams<ParamsType>;
type ParsingErrors = ValidationErrors<ParamsType>;

// define complex validation to apply if all basic validations pass
const expensiveValidation = async (params: MyQueryParams, context: PerRequestContext): Promise<string | undefined> => {
  return 'some expensive validation';
};

const queryParamsMiddleWare = createQueryParamsMiddleWare({
  params,
  validate: expensiveValidation
});

export default createHandlers({
  get: {
    handler: (req, res, context) => {
      // get all the parsed results and decide how to respond
      const myParams = context.getItem(PARSED_QUERY_PARAMS) as MyQueryParams;
      const errors = context.getItem(QUERY_PARAM_PARSER_ERRORS) as ParsingErrors;
      const complexError = context.getItem(QUERY_PARAM_VALIDATION_ERROR) as string | undefined;
      res.status(200).json({myParams, errors, complexError});
    },
    preHooks: [queryParamsMiddleWare]
  }
});

define a custom type

To define a custom type implement this ParamType<T>. This is enough to plug it in with and use within the definitions.

License

MIT License

Copyright (c) 2022 Mohnish Chowdhury

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.