Dude, where's my stocks

A programming exercise to write a Node.js REST service that returns stock ticker prices.

Go to https://dude-wheres-my-stocks.herokuapp.com/v2/GE to see it in action.

Endpoints

/v2/:ticker

Returns the current price of company's stock given the company's ticker at one of the stock exchanges in the USA.

Request

/v2/:ticker

The :ticker should be the symbol of a stock traded at one of stock exchanges in the USA, e.g. MSFT or GE.

Response

{
  ticker: "MSFT",
  currentPrice: 210.58
}

The ticker field contains the requested ticker.

The currentPrice field contains the current price of the stock in US dollars.

If you pass a non-existent ticker, the service will return currentPrice = 0.

[DEPRECATED] /v1/:ticker

DEPREACTED: This endpoint does not work correctly since Finnhub stopped offering non-US stocks in free tier. Use /v2/:ticker instead to get US stock prices.

Returns the current price of company's stock given the company's ticker at the Warsaw Stock Exchange.

Request

/v1/:ticker

The :ticker should be the symbol of a stock traded at the Warsaw Stock Exchange, e.g. CDR.

Response

{
  exchange: "XWAR",
  ticker: "CDR",
  currentPrice: 273.5
}

The exchange field contains the exchange's Market Identifier Code, according to ISO-10383.

The ticker field contains the requested ticker.

The currentPrice field contains the current price of the stock.

If you pass a non-existent ticker, the service will return currentPrice = 0.

Running the app

General notes

To run the app, you need to pass the Finnhub API KEY. To obtain it, register at https://www.finnhub.io.

If you do not pass the API key, the app might work for some time, but may quickly start returning 429 Too Many Requests.

If you pass an incorrect API key, the app will return 401 Unauthorized.

Running the app in Docker

Requirements:

• Docker

docker build -t stocks .
docker run -it --rm --env FINNHUB_API_KEY=your-api-key --publish 3000:3000 stocks

Visit http://localhost:3000 in your browser.

Running the app on bare metal

Requirements:

• Node.js - the version that is used in Dockerfile. It should be the latest (non-LTS) version.

npm ci
FINNHUB_API_KEY=your-api-key npm start

Visit http://localhost:3000 in your browser.

Running the tests

There are two types of tests at the moment: unit test and end-to-end tests.

Unit tests test the whole Express app while mocking out the external API.

End-to-end tests run the app without mocking the external API. They need your Finnhub API key to run.

Running unit tests

On bare metal:

npm run test:unit

With Docker:

docker build -t stocks .
docker run --rm stocks npm run test:unit

Running end-to-end tests

On bare metal:

FINNHUB_API_KEY=your-api-key npm run test:e2e

With Docker:

docker build -t stocks .
docker run --rm --env FINNHUB_API_KEY=your-api-key stocks npm run test:e2e