@antstackio/graphql-body-parser

graphql-body-parser

Parses and exposes the graphql query as graphql object in the request. Works as an express middleware, and build on top of body-parser module. As of now it only works with graphql request send with application/json as Content-Type.

How it works?

It looks for query and variable object in request body, and then parses the query into its AST. It then attaches both the AST object as well as variables to req as gqlObject property.

Request Body

  {
    "query": "query($name: String) {
               hello(name: $name){
               name
              }
            }",
    "variables": {
      "name": "khubo"
    }
  }

the parsed AST and variable will be attached as follows

req.gqlObject

{
  "operation": {
    "kind": "Document",
    "definitions": [
      {
        "kind": "OperationDefinition",
        "operation": "query",
        "variableDefinitions": [
          {
            "kind": "VariableDefinition",
            "variable": {
              "kind": "Variable",
              "name": {
                "kind": "Name",
                "value": "name"
              }
            },
            "type": {
              "kind": "NamedType",
              "name": {
                "kind": "Name",
                "value": "String"
              }
            },
            "directives": []
          }
        ],
        "directives": [],
        "selectionSet": {
          "kind": "SelectionSet",
          "selections": [
            {
              "kind": "Field",
              "name": {
                "kind": "Name",
                "value": "hello"
              },
              "arguments": [
                {
                  "kind": "Argument",
                  "name": {
                    "kind": "Name",
                    "value": "name"
                  },
                  "value": {
                    "kind": "Variable",
                    "name": {
                      "kind": "Name",
                      "value": "name"
                    }
                  }
                }
              ],
              "directives": [],
              "selectionSet": {
                "kind": "SelectionSet",
                "selections": [
                  {
                    "kind": "Field",
                    "name": {
                      "kind": "Name",
                      "value": "name"
                    },
                    "arguments": [],
                    "directives": []
                  }
                ]
              }
            }
          ]
        }
      }
    ],
    "loc": {
      "start": 0,
      "end": 94
    }
  },
  "variables": {
    "name": "khubo"
  }
}

Installation

$ npm install @antstackio/graphql-body-parser
$ yarn add @antstackio/graphql-body-parser

Usage

This can be used instead of normal json parser used with express

import * as express from "express";
import * as gqlParser from "@antstackio/graphql-body-parser";

const app = express();

app.use(gqlParser());

app.listen(process.env.PORT, () => {
  logger.info(`Node app running on port ${process.env.PORT} 🚀🚀`);
});