Haven Engineering Applicant Exercise

High-level scenario:

Goal: Given a list of port calls (a sample input can be found at /data/port-calls.json), generate the list of possible voyages. The goal is to get all tests to pass by running npm test

Definitions:

• Port Call: A stop along a ship's voyage, including the name/code of the port, the estimated time of arrival (ETA) at the port, and the estimated time of departure (ETD) from the port.
• Voyage: A trip from one port to another, including the ETD from the port of origin, and the ETA at the port of arrival.

Types of voyages

Across the same route

The simplest case of a voyage can be represented with the following:

• Two port calls on the same route (routeId)
• Where the two ports are different
• Where the etd of the port of origin is before the eta of the port of destination
• See the unit tests for an example: test/voyages.js#L5-L62

Across different routes (transhipments)

The more complex case of a transhipment voyage can be represented with the following:

• Two port calls on different routes (different routeId)
• Where the two ports are different
• Where the etd of the port of origin is before the eta of the port of destination
• And the two ports can be connected by another port
• For example, if the USS Harpoon goes from Hong Kong to Singapore, and the USS Starboard goes from Singapore to Oakland, we have a transhipment voyage from Hong Kong to Oakland.
• See the unit tests for an example: test/voyages.js#L178-L234

Things to consider

• You can assume a ship can stay at a port indefinitely before making a transhipment, i.e. if the USS Harpoon goes from Hong Kong and arrives in Singapore on January 1, and the USS Starboard departs from Singapore on February 1 a month later, a transhipment could still be valid.
• A voyage should not include any port more than once, i.e. the following voyage is invalid HKHKG -> SGSIN -> HKHKG -> USOAK because it stops in Hong Kong twice.

Sample output

Each voyage should contain at least the following fields, but feel free to add more:

{
  vessels: [String]   // Array since multiple vessels is possible
  routeIds: [Integer] // Array since multiple routes is possible
  origin: String      // e.g. HKHKG
  destination: String // e.g. USOAK
  etd: Date/String    // e.g. 2016-01-01 00:00:00
  eta: Date/String    // e.g. 2016-02-01 00:00:00
  isTranshipment: Boolean
}

Getting set up:

Make sure you're running Node v6 and then run

npm install

(If you need to upgrade your version of Node, this tool is handy)

Note: We prefer that you download this repository and email us ([email protected]) your solution as a zip file rather than forking it so that your solution may remain hidden from other candidates.

To log the output of passing in test data:

npm start

To run tests:

npm test