Koa-scheme NPM

koa-scheme

koa-scheme is a parameter validation middleware for koa.

version v3.0.0 support for koa2

Install

npm i koa-scheme --save

Usage

scheme(config, options)

config: {Object|String} scheme object or path.
options: {Object}
- debug: {Boolean} If true, print compiled config and throw error, Default false.

app.js

var koa = require('koa');
//var bodyParser = require('koa-bodyparser');
var scheme = require('koa-scheme');
var conf = require('./scheme');
var route = require('./route');

var app = koa();
//app.use(bodyParser());
app.use(scheme(conf));

route(app);

app.listen(3000, function() {
  console.log("listening on 3000")
});

scheme.json

{
  "/(.*)": {
    "request": {
      "header": {
        "version": "[1-9]+"        
      }
    }
  },
  "/": {
    "response": {
      "status": 200
    }
  },
  "GET /user/:username": {
    "response": {
      "body": {
        "name": /[a-z]+/i,
        "age": "[0-9]{1,3}"
      }
    }
  },
  "/user/:username": {
    "request": {
      "method": "(POST|patch)",
      "body": {
        "name": "[a-zA-Z]+",
        "age": /[0-9]{1,3}/
      }
    },
    "response": {
      "status": 200
    }
  },
  "(delete|OPTIONS) /user/:username": {
    ...
  }
}

see path-to-regexp.

NB: when use body-parser middleware (like: koa-bodyparser) before koa-scheme, you could configure 'body' field in 'request'.

use function:

scheme.js

module.exports = {
  "/users": {
    "request": {
      "method": "POST",
      "body": {
        "nameArr": testRequestNameArr
      }
    }
  }
}

function testRequestNameArr(arr) {
  if (arr.length === 3 && arr[1] === 'nswbmw') {
    return true;
  } else {
    return false;
  }
}

with validator:

scheme.js

var validator = require('validator');

module.exports = {
  "GET /user/:username": {
    "response": {
      "body": {
        "age": validator.isNumeric,
        "email": validator.isEmail,
        "webset": validator.isURL,
        ...
      }
    }
  }
}

Even you could write flat object like this:

{
  "GET /user/:username": {
    "response": {
      "body.age": validator.isNumeric,
      "body.email": validator.isEmail,
      "body.family.mother.age": validator.isNumeric
    }
  }
}

Example

scheme.js

var validator = require('validator');

module.exports = {
  "/(.*)": {
    "request": {
      "header.version": "[1-9]+"
    }
  },
  "/users": {
    "request": {
      "method": "GET"
    },
    "response": {
      "body": testRes
    }
  },
  "GET /user/:username": {
    "response": {
      "body": {
        "name": "[a-zA-Z]+",
        "age": validator.isNumeric,
        "email": validator.isEmail
      }
    }
  },
  "/user/:username": {
    "request": {
      "method": "(POST|PATCH)",
      "body.name": /[a-zA-Z]+/,
      "body.age": "[0-9]{1,3}",
      "body.email": validator.isEmail
    }
  },
  "(delete|OPTIONS) /user/:username": {
    "response": {
      "status": 200
    }
  }
}

// throw a error is ok
function testRes(arr) {
  throw new Error('badRequest');
}