app.py

#this is our app.py
from flask import Flask, request, jsonify

def create_app(test_config=None):
    app = Flask(__name__)
    if test_config:
        app.config.update(test_config) #testing = true... #database memory 
        
    app.posts = [] #to store all blog posts as list of dic
    app.next_id = 1  # to keep track of next post ID # home route (greeting function - default)
        
    @app.route("/")
    def home():
        return jsonify(message= "Welcome to our Blog for testing"), 200
    
    #list posts ->> to show all the post
    @app.route("/posts")
    def list_posts():
        return jsonify(posts=app.posts), 200
    
    
    #check ->>> create new posts with validation testing
    @app.route("/posts", methods=["POST"])
    def create_post():
        data = request.get_json()
        title = (data.get("title")or "").strip()
        body = (data.get("body")or "").strip()
        
        #validation
        if not title:
            return jsonify(error="Title Required"), 400
        if not body:
            return jsonify(error="Body Required"), 400
        
        #create post
        post = {"id": app.next_id, "title": title, "body": body}
        app.next_id += 1
        app.posts.append(post)
        return jsonify(post=post), 201
    
     
    
    return app