Test an in-app currency exchange between pockets

The checks that matter

Three pockets exist and only two should move, which is an assertion most conversion tests forget to make.

The GBP pocket is asserted at the start and never again, which is a gap worth closing in your own version. A conversion that touches an uninvolved balance is rare and expensive, and only a third assertion would catch it.

The flow as a test file

The rate and the resulting amount are asserted before the exchange, so the figures the customer agreed to are recorded independently of what the conversion produces.

---
mode: testing
url: https://my-testing-repo-main.vercel.app/revolut-clone-app/exchange?reset=true
max_steps: 40
tags: [revolut, fintech, fx]
---

# Revolat 19.2: Currency exchange

Catalog objective: exchange between two currency pockets.
Key assertion: both balances update at the quoted rate.

## Verify the starting pockets
Verify "Your pockets" shows "USD" of "$1240.50", "EUR" of "€180.00" and "GBP" of "£60.00".

## Set the exchange up
Leave "From" on "USD", select "EUR" in "To", type "100" into "Amount", and verify "Rate" reads "1 USD = 0.92 EUR" and "You get" reads "€92.00".

## Exchange
Click "Exchange" and verify a green banner titled "Exchange complete" says "$100.00" was exchanged for "€92.00" at 1 USD = 0.92 EUR.

## Verify both pockets moved
Verify "USD" now reads "$1140.50" and "EUR" now reads "€272.00".

The confirmation banner is asserted with the rate included, which means an exchange executed at a different rate than quoted fails at that step rather than being inferred from the balances.

Step by step coverage

A baseline, a quote, the exchange, and both sides verified.

Asserting both directions of the movement is the point. A credit that lands without a matching debit is a bug that customers do not report.

Adding it to a suite

kane-cli testmd run tests/revolut/currency-exchange_test.md

Extend the final step to assert the GBP pocket is unchanged, which closes the gap this file leaves open.

Balance-moving flows deserve evidence retained beyond the run. The open evidence format covers what is written out, and the test.md format covers storing a quoted rate as a variable for live environments.