App shows real-time exchange rate for a chosen pair of currencies and historical data in form of a graph. You can choose which range should be shown (min 7 days, max 10 years), of course if data is available on the server. For every range trendlines are generated - for increasing values, they are green and for decreasing values they are red. You can toggle the visibility of trendlines.

List of currencies is provided by openexchangerates.org. Real-time values are provided by alhavantage.co. Historical data are provided by alphavantage.co.

The app was written using Angular 7 (TypeScript 3.2.4). For styling Bootstrap 4 and CSS 3 was chosen. Charts are generated with Chart.js and ng2-charts. Unit tests were written using Jasmine/Karma environment.

Run ng serve for a dev server. Navigate to http://localhost:4200/. The app will automatically reload if you change any of the source files.

Free alphavantage key lets the user to make only 5 calls per minute and 500 per day. Jasmine has issues with testing Chart.js and therefore tests for methods using chart values are available, but commented out.