Sample Twitter Example

An Apollo GraphQL backend server for a minimal twitter-like GraphQL API.

Installing

To get started with graphql-twitter-example:

brew install node

Install dependencies:

cd graphql-twitter-example
npm install

Start apollo server:

cd graphql-twitter-example
nodemon src/index.js
[nodemon] 2.0.3
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node src/index.js`
🚀 Server ready at http://localhost:4000/

Navicate to localhost:4000

You should see:

Optional Seeding / Mutation

sequelize-cli is installed for extensibility of future schema changes.

Let’s say future you want to add a profile picture first,last names.

npx sequelize-cli model:generate --name User --attributes firstName:string,lastName:string,email:string,password:string

To seed db, populate the db with some accounts for testing:

npx sequelize-cli db:seed:all

APIs

Mutations

register - registers a email/password if it doesn’t exist

mutation Register($email:String, $password: String) {
  register(email: $email, password: $password) {
    success
    message
    email
  }
}

If successful:

{
  "data": {
    "register": {
      "success": true,
      "message": "User Created",
      "email": "jack.chi_3@gmail.com"
    }
  }
}

If email is already registered:

{
  "data": {
    "register": {
      "success": false,
      "message": "Email already taken.",
      "email": "jack.chi_1@gmail.com"
    }
  }
}

login - logs in the user via email/password

mutation LoginUser($email:String, $password: String) {
  login(email: $email, password: $password) {
    success
    message
    token
  }
}

If successful login, an Authorization Token will be returned.

{
  "data": {
    "login": {
      "success": true,
      "message": "Logged in!",
      "token": "$2b$10$vBm4xcoUn5gReSDKLrWQIeBiy.8sin2ROiLKL6TPvtF0N8Jo3brkG"
    }
  }
}

Then use the Authorization token on HTTP request headers:

{
  "authorization": "$2b$10$vBm4xcoUn5gReSDKLrWQIeBiy.8sin2ROiLKL6TPvtF0N8Jo3brkG"
}

createPost - creates a post from a String message

mutation CreatePost ($message: String) {
  createPost(message: $message) {
    success
    message
    userId
  }
}

Notice how we didn’t need to provide the email/password again.

{
  "data": {
    "createPost": {
      "success": true,
      "message": "Cash Point Card is awesome!",
      "userId": "5"
    }
  }
}

Query

me - gets the logged in user

query Me {
 me {
      id
      email
      posts {
      message
    }
    } 
}

response:

{
  "data": {
    "me": {
      "id": "5",
      "email": "jack.chi_3@gmail.com",
      "posts": null
    }
  }
}

posts

query GetPosts {
  posts {
    count
    posts {
      id
      userId
      message
      createdAt
    }
  }
}

response contains total count and the message with created at datestring

{
  "data": {
    "posts": {
      "count": 1,
      "posts": [
        {
          "id": "13",
          "userId": "5",
          "message": "Cash Point Card is awesome!",
          "createdAt": "5/3/2020, 9:35:57 AM"
        }
      ]
    }
  }
}

Further Explanations

PROS

• Currently using a sequelize for database orm. The datasource can be easily swapped out for mariadb/sql/etc.
• Choice of using Apollo GraphQL server can be federated across services.
• Simplicity!

CONS

• Account authentication security. Initially I experimented with accountjs-accounts/accounts but had issues with fragment inline types. I tried to extend the schema type User but it was too rigid to define @relations. This definitely needs to be fixed. Perhaps with Firebase REST datasource.

Acknowledgments

• Initially inspired by Point Card coding challenge