Create Endpoint for Exporting Donation Data to CSV

[aaronashby]

Overview

We want to set up an endpoint that allows us to export donation information to a CSV format.

Tasks

• Add GET /donations/export route in donations.controller.ts, ensuring that only admins can access that route.
  • If a non-admin tries to access the route, throw an UnauthorizedException
• Add a corresponding exportToCsv method in donations.service.ts. This function should generate a CSV file with columns for a donation's ID, first and last name, email, amount, type, interval (if recurring), date, and transaction ID
  • Since the CSV file could potentially be very large depending on how many donations are in the database, it may be useful to use file streaming (Documentation: https://docs.nestjs.com/techniques/streaming-files)
• Write unit tests to ensure that files are formatted correctly, and edge cases (e.g. no donations to format) are properly handled

Acceptance Criteria

• The controller should call the method in the service to export the donations in CSV format
• Only admins should be able to successfully call the route
• All unit tests pass