Personal Budget

Desctiption

This small api is based off of the envelope budgeting system. The concept is that a set of envelopes each represent a category of spending. The money you have to spend each month is divided accordingly and placed inside the corresponding envelope. When the time comes to pay for an expense, the money is withdrawn from the appropriate envelope. Money can also be transferred from one envelope to another if the situation calls for it. At the end of the month the money in the envelopes is refilled and the process begins again.

Technologies

1. JavaScript
2. Node.js
3. Express.js
4. PostgresSql
5. Openapi/Swagger

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Features

1. Built to scale.

• Moduler design allows new functionality to be added without affecting existing files.
• Route functionality is kept in seperate middleware functions to maintain separation of concerns and allow for re use in multiple routes.
• Helper functions are kept generic to allow for re-use by multiple modules for multiple purposes.
• Helper functions are used to obtain data, such that if the data storage method is changed, they can be refactored to return the same results, without affecting the rest of the server and allowing it to continue functioning as normal.

2. Paramaterized dynamic query functions.

• Generic functions use arguments to build dynamic queries which can be reused on any table regardless of columns.
• Queries are paramaterized to prevent SQL injection.
• Dynamic table and column names are escaped to prevent SQL injection.

3. User inputs validated and sanitized

• All user input is validated and sanitized before being used or storeed in order to prevent XSS

4. Data stored in database.

• All data is stored in a PostgresSql database.
• New entries are auto-assigned a unique v4 UUID.

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Summary of API Specification

Interactive swagger documentation can also be found here (note: swagger testing will not work propperly unless the server is hosted, it is currently set up for localhost:3000)

1. ENVELOPES ENDPOINTS

Endpoint: Get All Envelopes

• Description: Gets all of the envelopes from the database
• Path: /api/envelopes
• Method: GET
• Response: JSON array containing all envelopes

Endpoint: Get Envelope By Id

• Description: Gets the envelope of the specified Id from the database
• Path: /api/envelopes/{id}
• Method: GET
• Response: JSON object containing the envelope of the specified Id

Endpoint: Get Envelope Purchases By Id

• Description: Gets the purchases corresponding to the envelope of the specified Id from the database
• Path: /api/envelopes/{id}/purchases
• Method: GET
• Response: JSON object containing an array of the purchases corresponding to envelope of the specified Id

Endpoint: Add New Envelope

• Description: Adds a new envelope to the database and assigns it a unique v4 UUID
• Path: /api/envelopes/
• Method: POST
• Payload: JSON object {"category": string, "budget": xxxx.xx string}
• Response: JSON object containing the envelope along with it's newly assigned v4 UUID

Endpoint: Delete Envelope By Id

• Description: Deletes an envelope from the database
• Path: /api/envelopes/{id}
• Method: DELETE
• Response: JSON object containing the deleted envelope

Endpoint: Update Envelope By Id

• Description: Updates an envelope in the database with a specified new envelope
• Path: /api/envelopes/{id}
• Method: PUT
• Payload: JSON object {"category": string, "budget": xxxx.xx string} OR {"id": v4 UUID string, "category": string, "budget": xxxx.xx string}
• Response: JSON object containing the updated envelope

Endpoint: Transfer Envelope Budget

• Description: Updates two specified envelopes in the database by transferring a specified budget from one to another
• Path: /api/envelopes/{from-id}/transfer/{to-id}
• Method: PUT
• Payload: JSON object {"budget": xxxx.xx string}
• Response: JSON object containing an array of the updated envelopes

2. PURCHASES ENDPOINTS

Endpoint: Get All Purchases

• Description: Gets all of the purchases currently in the database
• Path: /api/purchases
• Method: GET
• Response: JSON array containing all purchases

Endpoint: Get Purchase By Id

• Description: Gets the purchase of the specified Id from the database
• Path: /api/purchases/{id}
• Method: GET
• Response: JSON object containing the purchase of the specified Id

Endpoint: Add New Purchase

• Description: Adds a new purchase to the database, assigns it a unique v4 UUID, and updates the budget of the corresponding envelope by subtracting the purchase amount
• Path: /api/purchases/
• Method: POST
• Payload: JSON object {"envelope_id": v4 UUID string, "date": YYYY-MM-DD string, "description": string, "amount": xxxx.xx string}
• Response: JSON object containing an array with the purchase along with it's newly assigned v4 UUID, and the corresponding envelope along with it's updated budget

Endpoint: Delete Purchase By Id

• Description: Deletes a purchse from the database
• Path: /api/purchases/{id}
• Method: DELETE
• Response: JSON object containing the deleted purchase

Endpoint: Update Purchase By Id

• Description: Updates a purchase in the database with a specified new purchase and updates the corresponding envelope with a new budget based on the difference between the new and old purchase
• Path: /api/purchase/{id}
• Method: PUT
• Payload: JSON object {"envelope_id": v4 UUID string, "date": YYYY-MM-DD string, "description": string, "amount": xxxx.xx string} OR {"id": v4 UUID string, "envelope_id": v4 UUID string, "date": YYYY-MM-DD string, "description": string, "amount": xxxx.xx string}
• Response: JSON object containing an array with the updated purchase, and the corresponding envelope along with it's updated budget

Acknowledgement

Thank you to Codecademy for creating this exercise and inspiration