app.py

"""
This is a Flask application that can be used to interview QA engineers. 
All the application does is to calculate the factorial of a number. 
But there have been bugs seeded. For example, this application will go into an infinite loop if you pass it a negative number.
To learn more, see the README.md of this application.
"""
from flask import Flask
from flask import jsonify
from flask import render_template
from flask import request

app = Flask(__name__)


def calculate_factorial(n):
    "Calculate the factorial of a number"
    if n == 0:
        return 1
    else:
        return n * calculate_factorial(n - 1)


@app.route("/", methods=["GET", "POST"])
@app.route("/factorial", methods=["GET", "POST"])
def factorial():
    "Endpoint for calculating the factorial of a number"
    if request.method == "GET":
        # return the form
        return render_template("factorial.html")
    if request.method == "POST":
        # return the answer
        number = int(request.form.get("number"))
        result = calculate_factorial(number)
        api_response = {"answer": result}
        return jsonify(api_response)


@app.route("/terms")
def terms_and_conditions():
    "Return terms and conditions"
    return "This is the terms and conditions document. We are not yet ready with it. Stay tuned!"


@app.route("/privacy")
def privacy():
    "Return privacy statement"
    return "This is the privacy document. We are not yet ready with it. Stay tuned!"


# ---START OF SCRIPT
if __name__ == "__main__":
    app.run()