sudheer121/CostExplorer

Cost Explorer assignment

Cost Explorer

Table of Contents

1. Built With
2. Installation
3. Documentation
   Project Structure
   Layers
   Helper Libraries
   Caching
   Data Types and Interfaces
4. API Testing

Built With

The project is build using NodeJS in Typescript. The web framework used is Express. Data ORM used is Sequelize.

1. Typescript is used because it is easier to understand as types are attached to each variable, also helps catch most bugs at compiletime
2. Sequelize ORM is used because it has good support for features like eager loading, nested loading, establishing relations between data and relational models.

Prerequisites

This is an example of how to list things you need to use the software and how to install them.

1. NodeJs
2. PostgreSQL

Installation

1. Clone the repo

   git clone https://github.com/Sudheer121/CostExplorer

2. Install NPM packages

   npm install

3. Setup data base from PostgreSQL dump

   psql -U user_name -d db_name -1 -f dump.sql

4. Fill .env parameters

   cp .env.example .env 
   

5. Run

   npx tsc
   npm run start:dev 
   

Documentation

Below is the documentation

Project Structure

Since the project is build with typescript source code is in ./src and complied javascript is in ./dist

Layers

The project layers consist of Models, Controller, Services and DAO layer

Helper Libraries

Custom created modules can be viewed at ./src/helpers. These modules are unrelated to project data but are useful in converting data from one form to other. These modules abstract away some of the logic.

Example : The Graph library takes data and creates an object that has graph representation of input data

Caching

Before the server starts, it caches the CostTypes table from database, it converts the data into graph form using Graph helper module. The cached data is stored in a static class CacheSingleton and is accessible throughout the project.

Data Types and Interfaces

Custom Data Types and Interfaces can be viewed at ./src/typings/index.d.ts. This alse has the interfaces CostExplorerOutput and ExplorerItem as specified.

Other than the provided interfaces the project uses commonly these interfaces.

1. IGraphNode

Represents a graph node, should have id and parent id

2. IData

Represents any data and should have id attribute

3. INest

Represents IData in nested form, ExplorerItem is a specific form of INest

API testing

Postman documentation will be added in sometime