Deposits Exercise

A tradeline on a credit report represents an account, such as a specific credit card.

In the codebase, the following exists:

• The Tradeline model, which can be used to store tradelines in the database.
• A Tradeline controller, which serves both the index and show routes for tradelines.
• Basic rspec tests on the controller with a tradeline FactoryBot.

Add in the ability to create deposits for a specific tradeline using a JSON API call. You should store the deposit date, and amount. Expose the outstanding balance for a given tradeline in the JSON output for TradelinesController#show, and TradelinesController#index. The oustanding balance should be calculated as the amount minus all of the deposit amounts.

In addition:

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

Feel free to add any gems to the Gemfile, and touch any of the existing code. For example, if you prefer to use PostgreSQL or MySQL over the included SQLite, or a serializer of your choice, please go ahead. This is not required, but you can be as creative as you want.

This exercise is purely API based, and will not have any frontend components. Please do not spend more than 3 hours on this.