Get a full fake GraphQL API with zero coding in less than 30 seconds.
I'd love to learn GraphQL, but it seems that I first have to read a book about GraphQL Types and Queries, then install a gazillion npm packages.
- About every developer
Start playing with GraphQL right away with json-graphql-server, a testing and mocking tool for GraphQL. All it takes is a JSON of your data.
Inspired by the excellent json-server.
Follow the guide below starting from scratch, or see the example live on StackBlitz:
Create a db.js file.
Your data file should export an object where the keys are the entity types. The values should be lists of entities, i.e. arrays of value objects with at least an id key. For instance:
module.exports = {
posts: [
{ id: 1, title: "Lorem Ipsum", views: 254, user_id: 123 },
{ id: 2, title: "Sic Dolor amet", views: 65, user_id: 456 },
],
users: [
{ id: 123, name: "John Doe" },
{ id: 456, name: "Jane Doe" }
],
comments: [
{ id: 987, post_id: 1, body: "Consectetur adipiscing elit", date: new Date('2017-07-03') },
{ id: 995, post_id: 1, body: "Nam molestie pellentesque dui", date: new Date('2017-08-17') }
]
}Start the GraphQL server on localhost, port 3000.
json-graphql-server db.jsTo use a port other than 3000, you can run json-graphql-server db.js --p <your port here>
To use a host other than localhost, you can run json-graphql-server db.js -h <your host here> or --host <your host here>
Now you can query your data in graphql. For instance, to issue the following query:
{
Post(id: 1) {
id
title
views
User {
name
}
Comments {
date
body
}
}
}Go to http://localhost:3000/?query=%7B%20Post%28id%3A%201%29%20%7B%20id%20title%20views%20User%20%7B%20name%20%7D%20Comments%20%7B%20date%20body%20%7D%20%7D%20%7D. You'll get the following result:
{
"data": {
"Post": {
"id": "1",
"title": "Lorem Ipsum",
"views": 254,
"User": {
"name": "John Doe"
},
"Comments": [
{ "date": "2017-07-03T00:00:00.000Z", "body": "Consectetur adipiscing elit" },
{ "date": "2017-08-17T00:00:00.000Z", "body": "Nam molestie pellentesque dui" },
]
}
}
}The json-graphql-server accepts queries in GET and POST. Under the hood, it uses the express-graphql module. Please refer to their documentations for details about passing variables, etc.
Note that the server is GraphiQL enabled, so you can query your server using a full-featured graphical user interface, providing autosuggest, history, etc. Just browse http://localhost:3000/ to access it.
npm install -g json-graphql-serverBased on your data, json-graphql-server will generate a schema with one type per entity, as well as 3 query types and 3 mutation types. For instance for the Post entity:
type Query {
Post(id: ID!): Post
allPosts(page: Int, perPage: Int, sortField: String, sortOrder: String, filter: PostFilter): [Post]
_allPostsMeta(page: Int, perPage: Int, sortField: String, sortOrder: String, filter: PostFilter): ListMetadata
}
type Mutation {
createPost(data: String): Post
createManyPost(data: [{data:String}]): [Post]
updatePost(data: String): Post
removePost(id: ID!): Post
}
type Post {
id: ID!
title: String!
views: Int!
user_id: ID!
User: User
Comments: [Comment]
}
type PostFilter {
q: String
id: ID
id_neq: ID
title: String
title_neq: String
views: Int
views_lt: Int
views_lte: Int
views_gt: Int
views_gte: Int
views_neq: Int
user_id: ID
user_id_neq: ID
}
type ListMetadata {
count: Int!
}
scalar DateBy convention, json-graphql-server expects all entities to have an id field that is unique for their type - it's the entity primary key. The type of every field is inferred from the values, so for instance, Post.title is a String!, and Post.views is an Int!. When all entities have a value for a field, json-graphql-server makes the field type non nullable (that's why Post.views type is Int! and not Int).
For every field named *_id, json-graphql-server creates a two-way relationship, to let you fetch related entities from both sides. For instance, the presence of the user_id field in the posts entity leads to the ability to fetch the related User for a Post - and the related Posts for a User.
The all* queries accept parameters to let you sort, paginate, and filter the list of results. You can filter by any field, not just the primary key. For instance, you can get the posts written by user 123. Json-graphql-server also adds a full-text query field named q, and created range filter fields for numeric and date fields. All types (excluding booleans and arrays) get a not equal filter. The detail of all available filters can be seen in the generated *Filter type.
| Type | GraphQL Type | Rule | Example value |
|---|---|---|---|
| Id | GraphQLID |
name === 'id' || name.substr(name.length - 3) === '_id' |
1 |
| Integer | GraphQLInt |
Number.isInteger(value) |
12 |
| Numeric | GraphQLFloat |
!isNaN(parseFloat(value)) && isFinite(value) |
12.34 |
| Boolean | GraphQLBoolean |
typeof value === 'boolean' |
false |
| String | GraphQLString |
typeof value === 'string' |
'foo' |
| Array | GraphQLList |
Array.isArray(value) |
['bar'], [12, 34] |
| Date | DateType (custom) |
value instanceof Date || isISODateString(value) |
new Date('2016-06-10T15:49:14.236Z'), '2016-06-10T15:49:14.236Z' |
| Object | GraphQLJSON |
Object.prototype.toString.call(value) === '[object Object]' |
transport: { service: 'fakemail', auth: { user: '[email protected]', pass: 'f00b@r' } } |
Here is how you can use the queries and mutations generated for your data, using Post as an example:
| Query / Mutation | Result |
|---|---|
// get a single entity, by id
{
Post(id: 1) {
id
title
views
user_id
}
}
|
{
"data": {
"Post": {
"id": 1,
"title": "Lorem Ipsum",
"views": 254,
"user_id": 123
}
}
}
|
// include many-to-one relationships
{
Post(id: 1) {
title
User {
name
}
}
}
|
{
"data": {
"Post": {
"title": "Lorem Ipsum",
"User": {
"name": "John Doe"
}
}
}
}
|
// include one-to-many relationships
{
Post(id: 1) {
title
Comments {
body
}
}
}
|
{
"data": {
"Post": {
"title": "Lorem Ipsum",
"Comments": [
{ "body": "Consectetur adipiscing elit" },
{ "body": "Nam molestie pellentesque dui" },
]
}
}
}
|
// get a list of entities for a type
{
allPosts {
title
views
}
}
|
{
"data": {
"allPosts": [
{ "title": "Lorem Ipsum", views: 254 },
{ "title": "Sic Dolor amet", views: 65 }
]
}
}
|
// paginate the results
{
allPosts(page: 0, perPage: 1) {
title
views
}
}
|
{
"data": {
"allPosts": [
{ "title": "Lorem Ipsum", views: 254 },
]
}
}
|
// sort the results by field
{
allPosts(sortField: "title", sortOrder: "desc") {
title
views
}
}
|
{
"data": {
"allPosts": [
{ "title": "Sic Dolor amet", views: 65 }
{ "title": "Lorem Ipsum", views: 254 },
]
}
}
|
// filter the results using the full-text filter
{
allPosts(filter: { q: "lorem" }) {
title
views
}
}
|
{
"data": {
"allPosts": [
{ "title": "Lorem Ipsum", views: 254 },
]
}
}
|
// filter the result using any of the entity fields
{
allPosts(filter: { views: 254 }) {
title
views
}
}
|
{
"data": {
"allPosts": [
{ "title": "Lorem Ipsum", views: 254 },
]
}
}
|
// all fields (except boolean and array) get not equal filters
// -lt, _lte, -gt, and _gte
{
allPosts(filter: { title_neq: "Lorem Ipsum" }) {
title
views
}
}
|
{
"data": {
"allPosts": [
{ "title": "Some Other Title", views: 254 },
]
}
}
|
// number fields get range filters
// -lt, _lte, -gt, and _gte
{
allPosts(filter: { views_gte: 200 }) {
title
views
}
}
|
{
"data": {
"allPosts": [
{ "title": "Lorem Ipsum", views: 254 },
]
}
}
|
Install the module locally:
npm install --save-dev json-graphql-serverThen use the jsonGraphqlExpress express middleware:
import express from 'express';
import jsonGraphqlExpress from 'json-graphql-server';
const PORT = 3000;
const app = express();
const data = {
// ... your data
};
app.use('/graphql', jsonGraphqlExpress.default(data));
app.listen(PORT);Useful when using XMLHttpRequest directly or libraries such as axios.
Add a script tag referencing the library:
<script src="../lib/json-graphql-server.client.min.js"></script>It will expose the JsonGraphqlServer as a global object:
<script type="text/javascript">
window.addEventListener('load', function() {
const data = [...];
const server = JsonGraphqlServer({
data,
url: 'http://localhost:3000/graphql'
});
server.start();
const xhr = new XMLHttpRequest();
xhr.open('POST', 'http://localhost:3000/graphql', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.setRequestHeader('Accept', 'application/json');
xhr.onerror = function(error) {
console.error(error);
}
xhr.onload = function() {
const result = JSON.parse(xhr.responseText);
console.log('data returned:', result);
alert('Found ' + result.data.allPosts.length + ' posts');
}
const body = JSON.stringify({ query: 'query allPosts { allPosts { id } }' });
xhr.send(body);
});
</script>npm install json-graphql-serverimport JsonGraphqlServer from 'json-graphql-server';
const data = [...];
const server = JsonGraphqlServer({
data,
url: 'http://localhost:3000/graphql'
});
server.start();
const xhr = new XMLHttpRequest();
xhr.open('POST', 'http://localhost:3000/graphql', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.setRequestHeader('Accept', 'application/json');
xhr.onerror = function(error) {
console.error(error);
}
xhr.onload = function() {
const result = JSON.parse(xhr.responseText);
console.log('data returned:', result);
alert('Found ' + result.data.allPosts.length + ' posts');
}
const body = JSON.stringify({ query: 'query allPosts { allPosts { id } }' });
xhr.send(body);import fetchMock from 'fetch-mock';
import JsonGraphqlServer from 'json-graphql-server';
const data = [...];
const server = JsonGraphqlServer({ data });
fetchMock.post('http://localhost:3000/graphql', server.getHandler());
fetch({
url: 'http://localhost:3000/graphql',
method: 'POST',
body: JSON.stringify({ query: 'query allPosts { allPosts { id } }' })
})
.then(response => response.json())
.then(json => {
alert('Found ' + result.data.allPosts.length + ' posts');
})json-graphql-server doesn't deal with authentication or custom routes. But you can use your favorite middleware with Express:
import express from 'express';
import jsonGraphqlExpress from 'json-graphql-server';
import OAuthSecurityMiddleWare from './path/to/OAuthSecurityMiddleWare';
const PORT = 3000;
const app = express();
const data = {
// ... your data
};
app.use(OAuthSecurityMiddleWare());
app.use('/graphql', jsonGraphqlExpress(data));
app.listen(PORT);You can also use the export jsonSchemaBuilder to get your own copy of the GraphQLSchema:
In node:
import {graphql} from 'graphql';
import {jsonSchemaBuilder} from 'json-graphql-server';
const data = { };
const schema = jsonSchemaBuilder(data);
const query = `[...]`
graphql(schema, query).then(result => {
console.log(result);
});Or available in the global scope when running on a client as jsonSchemaBuilder.
If you want to use another server type instead of the built in graphql express, like apollo-server or etc, you can expose the plain schema to be built into an executable schema (there may be version issues otherwise).
This uses the export getPlainSchema.
import { ApolloServer } from 'apollo-server';
import { makeExecutableSchema } from '@graphql-tools/schema'; // or graphql-tools
import { applyMiddleware } from 'graphql-middleware';
import { getPlainSchema } from 'json-graphql-server';
const data = { };
// Example middlewares
const logInput = async (resolve, root, args, context, info) => {
console.log(`1. logInput: ${JSON.stringify(args)}`);
const result = await resolve(root, args, context, info);
console.log(`5. logInput`);
return result;
};
const logResult = async (resolve, root, args, context, info) => {
console.log(`2. logResult`);
const result = await resolve(root, args, context, info);
console.log(`4. logResult: ${JSON.stringify(result)}`);
return result;
};
// Leverage getPlainSchema
const schema = applyMiddleware(
makeExecutableSchema(getPlainSchema(data)),
logInput,
logResult
);
const server = new ApolloServer({
schema,
});
server.listen({ port: 3000 });Deploy with Heroku or Next.js.
- CLI options (https, watch, delay, custom schema)
- Subscriptions
- Client-side mocking (à la FakeRest)
Use Prettier formatting and make sure you include unit tests. The project includes a Makefile to automate usual developer tasks:
make install
make build
make test
make watch
make formatTo learn more about the contributions to this project, consult the contribution guide.
 |
 |
 |
|---|---|---|
| Francois Zaninotto | Gildas Garcia | Alexis Janvier |
json-graphql-server is licensed under the MIT Licence, sponsored and supported by marmelab.
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