Payments Exercise

Add in the ability to create payments for a given loan using a JSON API call. You should store the payment date and amount. Expose the outstanding balance for a given loan in the JSON vended for LoansController#show and LoansController#index. The outstanding balance should be calculated as the funded_amount minus all of the payment amounts.

A payment should not be able to be created that exceeds the outstanding balance of a loan. You should return validation errors if a payment can not be created. Expose endpoints for seeing all payments for a given loan as well as seeing an individual payment.

How it works

LoansController#index will show all performed payments, including date, loan balance, amount of the payment for each register. (i.e. http://localhost:3000/loans/1)

LoansController#show will show the initial amount of the loan, the outstanding balance and the total number of payments made. (i.e. http://localhost:3000/loans)

set the environment

cd ~/.rbenv/plugins/ruby-build && git pull && cd -
rbenv install 2.5.3
gem install rails
gem install rspec
gem install bundler
gem i bundler -v 1.17.3
rails db:migrate

run the server

rails s

check the sqlite databases

sqlite3 db/development.sqlite3
.schema payments
.schema loans

SELECT * FROM loans;
SELECT * FROM payments;

.quit

make a payment with Postman

POST http://localhost:3000/loans

• Headers Key: Content-Type Value: application/json

• Body raw JSON (application/json)

{ "amount": 100 }