npjd/htn-backend-take-home

Setup

Run the following to get the server running

npm install

npm start

This will automatically create a DB locally. Apollo Playground will also be running; you can interact with it at http://localhost:4000/

Tests

I've provided a suite of jest tests

npm test

These are also integrated into Github Actions

Features

Types

User

A user represents an individual in the system.

Field	Type	Description
id	ID!	Unique identifier
name	String!	Name of the user
company	String	Company the user belongs to (optional)
email	String!	Email address of the user
phone	String!	Phone number of the user
skills	[Skill!]!	List of skills possessed by the user
events	[Event!]!	List of events associated with the user
owned_hardware	[HardwareOwners!]!	List of hardware owned by the user

HardwareOwners

Represents the ownership relationship between users and hardware.

Field	Type	Description
user_id	ID!	ID of the user who owns the hardware
owned_quantity	Int!	Quantity of hardware owned by the user

Hardware

Represents hardware available in the system.

Field	Type	Description
id	ID!	Unique identifier
name	String!	Name of the hardware
total_quantity	Int!	Total quantity of the hardware
available_quantity	Int!	Available quantity of the hardware
owners	[HardwareOwners!]!	List of users who own this hardware

Event

Represents an event associated with a user.

Field	Type	Description
id	ID!	Unique identifier
event	String!	Description of the event
scanned_at	String!	Timestamp when the event was scanned

Skill

Represents a skill possessed by a user.

Field	Type	Description
id	ID!	Unique identifier
skill	String!	Name of the skill
rating	Int!	Rating of the skill (e.g., proficiency level)

SkillFrequency

Represents the frequency of a skill across users.

Field	Type	Description
skill	String!	Name of the skill
frequency	Int!	Frequency of the skill across users

Queries

users: Retrieve a list of all users.
user(userId: ID!): Retrieve a user by their ID.
skills(min_frequency: Int, max_frequency: Int): Retrieve skills within a frequency range.
hardware: Retrieve a list of all hardware.
hardwareById(hardwareId: ID!): Retrieve hardware by its ID.

Mutations

updateUser(userId: ID!, data: UpdateUserInput!): Update user information.
scanUser(userId: ID!, event: String!): Record an event for a user.
checkOutHardware(hardwareId: ID!, userId: ID!, quantity: Int!): Check out hardware to a user.
checkInHardware(hardwareId: ID!, userId: ID!, quantity: Int!): Check in hardware from a user.

Example Requests

Retrieve all users

query {
  users {
    id
    name
    email
    phone
  }
}

Retrieve a user by ID

query {
  user(userId: "userId") {
    id
    name
    email
    company
    skills {
      id
      skill
      rating
    }
  }
}

Update user information

mutation {
  updateUser(userId: "userId", data: { name: "New Name", company: "New Company" }) {
    id
    name
    company
  }
}

Record an event for a user

mutation {
  scanUser(userId: "userId", event: "Scanned at Entrance") 
}

Check out hardware to a user

mutation {
  checkOutHardware(hardwareId: "exampleHardwareId", userId: "exampleUserId", quantity: 1)
}

Retrieve skills within a frequency range

query {
  skills(min_frequency: 2, max_frequency: 5) {
    skill
    frequency
  }
}

Tech Stack

TypeScript: A statically typed superset of JavaScript that compiles to plain JavaScript. It's used for writing the server-side code.
Node.js: A JavaScript runtime built on Chrome's V8 JavaScript engine. It's used for running the server-side code.
Express.js: A minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.
Apollo Server: A community-driven, open-source GraphQL server that works with any GraphQL schema. It's used for creating GraphQL server.
GraphQL: A query language for APIs and a runtime for executing those queries with your existing data.
SQLite3: A C library that provides a lightweight disk-based database. It allows accessing the database using a nonstandard variant of the SQL query language.
npm: A package manager for the JavaScript programming language. It's used for managing project dependencies.
ts-node: A TypeScript execution and REPL for Node.js, with source map support. It's used for running TypeScript code directly, without compiling it first.
Jest JavaScript Testing Framework
Babel JavaScript compiler that lets us run Jest with TypeScript
Github Actions Useful for CI/CD to make sure production branches have valid builds

Future Features

Find a way to inherit types in the schema to reduce redundancy
Organize DB such that we have a log of hardware transactions for better monitoring
Find a way to export types from schema to resolver code for better consistency across codebase
Have the DB hosted on a server
The code in resolver.ts does not scale well imo if we were to add more features — it would be best to have each resolver have its functionality split across modules, and to have some common functions all these modules could interact with — for a small project like this I decided to just dump all the logic in one file
Make the tests db separate from the server DB
More robust test suite

Hopefully, this is sufficient though! I enjoyed working on this and hopefully, I can keep doing this work with Hack the North!

npjd / htn-backend-take-home