Flask Code Challenge - Superheroes

For this assessment, you'll be working on an API for tracking heroes and their superpowers.

In this repo:

• There is a Flask application with some features built out.
• There is a fully built React frontend application.
• There are tests included which you can run using pytest -x.
• There is a file challenge-2-superheroes.postman_collection.json that contains a Postman collection of requests for testing each route you will implement.

Depending on your preference, you can either check your API by:

• Using Postman to make requests
• Running pytest -x and seeing if your code passes the tests
• Running the React application in the browser and interacting with the API via the frontend

You can import challenge-2-superheroes.postman_collection.json into Postman by pressing the Import button.

Select Upload Files, navigate to this repo folder, and select challenge-2-superheroes.postman_collection.json as the file to import.

Setup

The instructions assume you changed into the code-challenge folder prior to opening the code editor.

To download the dependencies for the frontend and backend, run:

pipenv install
pipenv shell
npm install --prefix client

You can run your Flask API on localhost:5555 by running:

python server/app.py

You can run your React app on localhost:4000 by running:

npm start --prefix client

You are not being assessed on React, and you don't have to update any of the React code; the frontend code is available just so that you can test out the behavior of your API in a realistic setting.

Your job is to build out the Flask API to add the functionality described in the deliverables below.

Models

You will implement an API for the following data model:

The file server/models.py defines the model classes without relationships. Use the following commands to create the initial database app.db:

export FLASK_APP=server/app.py
flask db init
flask db upgrade head

Now you can implement the relationships as shown in the ER Diagram:

• A Hero has many Powers through HeroPower
• A Power has many Heros through HeroPower
• A HeroPower belongs to a Hero and belongs to a Power

Update server/models.py to establish the model relationships. Since a HeroPower belongs to a Hero and a Power, configure the model to cascade deletes.

Set serialization rules to limit the recursion depth.

Run the migrations and seed the database:

flask db revision --autogenerate -m 'message'
flask db upgrade head
python server/seed.py

If you aren't able to get the provided seed file working, you are welcome to generate your own seed data to test the application.

Validations

Add validations to the HeroPower model:

• strength must be one of the following values: 'Strong', 'Weak', 'Average'

Add validations to the Power model:

• description must be present and at least 20 characters long

Routes

Set up the following routes. Make sure to return JSON data in the format specified along with the appropriate HTTP verb.

Recall you can specify fields to include or exclude when serializing a model instance to a dictionary using to_dict() (don't forget the comma if specifying a single field).

NOTE: If you choose to implement a Flask-RESTful app, you need to add code to instantiate the Api class in server/app.py.

GET /heroes

Return JSON data in the format below:

[
  {
    "id": 1,
    "name": "Kamala Khan",
    "super_name": "Ms. Marvel"
  },
  {
    "id": 2,
    "name": "Doreen Green",
    "super_name": "Squirrel Girl"
  },
  {
    "id": 3,
    "name": "Gwen Stacy",
    "super_name": "Spider-Gwen"
  },
  {
    "id": 4,
    "name": "Janet Van Dyne",
    "super_name": "The Wasp"
  },
  {
    "id": 5,
    "name": "Wanda Maximoff",
    "super_name": "Scarlet Witch"
  },
  {
    "id": 6,
    "name": "Carol Danvers",
    "super_name": "Captain Marvel"
  },
  {
    "id": 7,
    "name": "Jean Grey",
    "super_name": "Dark Phoenix"
  },
  {
    "id": 8,
    "name": "Ororo Munroe",
    "super_name": "Storm"
  },
  {
    "id": 9,
    "name": "Kitty Pryde",
    "super_name": "Shadowcat"
  },
  {
    "id": 10,
    "name": "Elektra Natchios",
    "super_name": "Elektra"
  }
]

GET /heroes/:id

If the Hero exists, return JSON data in the format below:

{
  "id": 1,
  "name": "Kamala Khan",
  "super_name": "Ms. Marvel",
  "hero_powers": [
    {
      "hero_id": 1,
      "id": 1,
      "power": {
        "description": "gives the wielder the ability to fly through the skies at supersonic speed",
        "id": 2,
        "name": "flight"
      },
      "power_id": 2,
      "strength": "Strong"
    }
  ]
}

If the Hero does not exist, return the following JSON data, along with the appropriate HTTP status code:

{
  "error": "Hero not found"
}

GET /powers

Return JSON data in the format below:

[
  {
    "description": "gives the wielder super-human strengths",
    "id": 1,
    "name": "super strength"
  },
  {
    "description": "gives the wielder the ability to fly through the skies at supersonic speed",
    "id": 2,
    "name": "flight"
  },
  {
    "description": "allows the wielder to use her senses at a super-human level",
    "id": 3,
    "name": "super human senses"
  },
  {
    "description": "can stretch the human body to extreme lengths",
    "id": 4,
    "name": "elasticity"
  }
]

GET /powers/:id

If the Power exists, return JSON data in the format below:

{
  "description": "gives the wielder super-human strengths",
  "id": 1,
  "name": "super strength"
}

If the Power does not exist, return the following JSON data, along with the appropriate HTTP status code:

{
  "error": "Power not found"
}

PATCH /powers/:id

This route should update an existing Power. It should accept an object with the following properties in the body of the request:

{
  "description": "Valid Updated Description"
}

If the Power exists and is updated successfully (passes validations), update its description and return JSON data in the format below:

{
  "description": "Valid Updated Description",
  "id": 1,
  "name": "super strength"
}

If the Power does not exist, return the following JSON data, along with the appropriate HTTP status code:

{
  "error": "Power not found"
}

If the Power is not updated successfully (does not pass validations), return the following JSON data, along with the appropriate HTTP status code:

{
  "errors": ["validation errors"]
}

POST /hero_powers

This route should create a new HeroPower that is associated with an existing Power and Hero. It should accept an object with the following properties in the body of the request:

{
  "strength": "Average",
  "power_id": 1,
  "hero_id": 3
}

If the HeroPower is created successfully, send back a response with the data related to the new HeroPower:

{
  "id": 11,
  "hero_id": 3,
  "power_id": 1,
  "strength": "Average",
  "hero": {
    "id": 3,
    "name": "Gwen Stacy",
    "super_name": "Spider-Gwen"
  },
  "power": {
    "description": "gives the wielder super-human strengths",
    "id": 1,
    "name": "super strength"
  }
}

If the HeroPower is not created successfully, return the following JSON data, along with the appropriate HTTP status code:

{
  "errors": ["validation errors"]
}