Registry / testing / json-graphql-server

json-graphql-server

library3.3.1jsnpmunverified

json-graphql-server version 3.3.1 is a zero-configuration GraphQL testing and mocking tool for Node.js. Given a JSON data file or JavaScript module exporting arrays of entities, it spins up a full GraphQL API (queries, mutations, filters, pagination, sorting, and relationships) on localhost in under 30 seconds, no schema writing needed. Released under MIT with contributors from Marmelab; updates are infrequent but stable. Compared to alternatives like json-graphql-mocker or graphql-faker, this tool provides automatic schema generation and GraphiQL IDE out of the box, but does not support authentication, custom resolvers, or complex business logic.

testing api

npm install json-graphql-server

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · JSON-GRAPHQL-SERVE

json-graphql-server

testingjavascriptv3.3.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default (express middleware)

✓ const jsonGraphqlServer = require('json-graphql-server');

✗ import jsonGraphqlServer from 'json-graphql-server';

The library exports an Express middleware function via CommonJS. ESM import with default may fail before version 4 (if ever). Use require or dynamic import().

expressMiddleware

✓ const expressMiddleware = require('json-graphql-server').default || require('json-graphql-server');

✗ import { expressMiddleware } from 'json-graphql-server';

The package does not export named 'expressMiddleware' in v3.3.1. Use the default export or check docs for exact export name.

graphqlSchema

✓ const { graphql } = require('json-graphql-server');

✗ import { graphql } from 'json-graphql-server';

The library may export a 'graphql' function for building schema. Not well documented; prefer using the CLI or middleware.

Create a data file exporting entity arrays, then start server via CLI or programmatic middleware for zero-config GraphQL API.

// db.js module.exports = { posts: [ { id: 1, title: "Hello", views: 100, user_id: 10 }, { id: 2, title: "World", views: 200, user_id: 20 } ], users: [ { id: 10, name: "Alice" }, { id: 20, name: "Bob" } ] };

Debug

Known issues

gotchaSchema generation inflects entity names; 'posts' becomes 'Post' type, 'allPosts' query. Ensure consistent plural/singular.

fix

Name your keys as plural lowercase (e.g., 'posts', 'users') to match expected conventions.

affects: >=2.0 <4.0

breakingMutations return 'data' and 'error' fields; error handling differs from standard GraphQL as errors may be in 'error' key instead of 'errors' array.

fix

Check both 'errors' and 'error' in response; prefer using the 'graphql-http' client for compatibility.

affects: >=3.0 <4.0

deprecatedCLI option '--p' for port is deprecated in favor of '--port' (full name).

fix

Use '--port' instead of '-p' or '--p'.

affects: >=3.0

gotchaIDs must be unique across all entities of the same type; duplicate IDs cause undefined behavior.

fix

Ensure each entity in an array has a unique 'id' field, numeric or string.

affects: >=1.0

Errors

Common errors & fixes

Error: Cannot find module 'json-graphql-server'

Package not installed or globally installed when using npx without local install.

fix

Run 'npm install -D json-graphql-server' in your project, or use 'npx json-graphql-server' with care (must be installed).

TypeError: jsonGraphqlServer is not a function

Using ESM import (import jsonGraphqlServer from 'json-graphql-server') which does not work because package uses CommonJS default export.

fix

Use require: const jsonGraphqlServer = require('json-graphql-server');

GraphQLError: Cannot query field "allPosts" on type "Query"

The data file has key 'posts' but the schema generated 'Post' type and 'allPosts' query; querying 'allPost' (typo) fails.

fix

Check your entity key names and use correct query names (e.g., 'allPosts', 'allUsers').

Upgrade

Version history

3.3.1latest on npm

Audit

Dependencies

graphqlrequiredPeer dependency for GraphQL execution and schema construction

inflectionrequiredUsed for pluralization/singularization of entity names in generated schema

Agent activity

47 hits · last 30 days

node

OpenAI (training)

Resources

githubssh://git@github.com/marmelab/json-graphql-server ↗

packagejson-graphql-server ↗

homepagehttps://github.com/marmelab/json-graphql-server#readme ↗