A feature rich GraphQL Express server

This solution uses PosgreSQL for persistence of data.

Features

• Express powered Apollo Server
• PostgreSQL connectivity via Sequelize
• Multiple queries and mutations
• Subscriptions for real-time communication
• PostgreSQL linked resolvers
• Schema documentation via GraphiQL
• Custom validation and error handling
• User registration and token based authentication
• User authorisation via resolver middleware
• Custom scalars
• Cursor-based pagination
• E2E testing
• Batching and caching
• Deployed to Heroku

Prerequisites

As PostgreSQL maintains the persistence of data, you will need to create a .env file in order to connect to your database.

The .env file should look something like this:

DATABASE=postgres
TEST_DATABASE=postgres_test
DATABASE_USER=postgres
DATABASE_PASSWORD=postgres

SECRET=myverysecuresecretphrase

and must be placed in the root of this repository.

* src/
* node_modules/
.babelrc
-----------  .env  -----------
.gitattributes
.gitignore
README.md
package-lock.json
package.json

NOTE: Declaring the variable TEST_DATABASE will purge all of your existing records and seed your database with new, fresh data on server restart.

Available Schemas

NOTE: A secret is passed to all resolver functions. Some of these queries and/ or mutations require a secret to be defined. It can be added as a SECRET parameter in your .env file - to be used as an environment variable via the dotenv dependency. See the Prerequisites section for more info.

Users

List all users

{
    users {
        id
        username
        email
        messages {
            id
            text
            createdAt
        }
    }
}

List a specific user by user ID

{
    user(id: 4) {
        id
        username
        email
    }
}

Sign Up

mutation {
    signUp(username: "TestUser", email: "[email protected]", password: "password123") {
        token
    }
}

Sign In

mutation {
    signIn(login: "TestUser", password: "password123") {
        token
    }
}

Show the 'me' user

{
    me {
        id
        username
        email
        messages {
            id
            text
            createdAt
        }
    }
}

Delete user

NOTE: To use this mutation, the user is required to signIn with an account that has the role of ADMIN.

mutation {
  deleteUser(id: "2")
}

Update user

NOTE: To use this mutation, the user is required to signIn with a valid account. It will update this user's username.

mutation {
  updateUser(username: "jappleseed") {
      id
      username
      email
  }
}

Messages

List all messages

NOTE: This particular example uses cursor based pagination on the createdAt field. It will retrieve the earliest created messages.

{
    messages(limit: 2) {
        edges {
            id
            text
            createdAt
        }
        pageInfo {
            hasNextPage
            endCursor
        } 
    }
  
    messages(limit: 1, cursor: "RnJpIFNlcCAwNiAyMDE5IDEyOjM0OjE5IEdNVCswMTAwIChCcml0aXNoIFN1bW1lciBUaW1lKQ==") {
        edges {
            id
            text
            createdAt
        }
        pageInfo {
            hasNextPage
            endCursor
        }
    }
}

List a specific message by message ID

{
    message(id: "2") {
        id
        text
        createdAt
        user {
            id
            username
            email
        }
    }
}

Create a new message

NOTE: At the moment, this mutation requires a 'me' User object to exit in src/index.js - as a User must exist for a Message object to be created.

mutation {
    createMessage(text: "Cake") {
        id
        text
        createdAt
    }
}

Delete a specific message by message ID

mutation {
    deleteMessage(id: "4")
}

Subscriptions

Message Created

subscription {
    messageCreated {
        message {
            id
            text
            createdAt
            user {
                id
                username
            }
        }
    }
}

Run the application

Install dependencies:

npm i

Start server:

NOTE: Make sure your PostgreSQL server is running before you start the application.

npm start

Access GraphiQL at: http://localhost:8000/graphiql

E2E Tests

NOTE: Make sure your PostgreSQL server is running before you start testing, otherwise the tests will fail.

All tests can be found in the src/tests folder.

They can be executed using:

npm test