skeithtan/solutions-engineer-test

Stack Overview

The solution stack is written on TypeScript as the language on the Node.js runtime. The Object Relational Mapping in the solution uses the TypeORM library. The database itself is an instance of SQL.js, an in-memory database, to simplify running the solution. In a production environment, this can easily be substituted with other database drivers (i.e., PostgreSQL, MySQL, etc.) by specifying the connection options in the configuration file.

The stack uses Koa.js as the web framework. Request objects are validated through defined schemas using the Joi validation library and Winston logs events to the console and/or to files. The testing framework is Jest.

First launch prerequisites

Certain environmental variables must be specified to run the server. These environmental variables can be injected to the instance in a production environment or read from a .env file in a development environment.

To launch the solution, create a .env file at the root folder of the project, and paste the following values:

# Server
SERVER_PORT=8000

# Logger
LOGGER_LEVEL=info
LOGGER_ERROR_LOG_FILENAME=error.log
LOGGER_COMBINED_LOG_FILENAME=combined.log

# TypeORM
TYPEORM_CONNECTION=sqljs
TYPEORM_SYNCHRONIZE=true
TYPEORM_LOGGING=false
TYPEORM_ENTITIES=src/entities/**/*.ts

Then proceed to install all dependencies using yarn.

Scripts

The package.json contains scripts to facilitate actions.

Test suite

Runs the test suite with Jest. Ensure that the server port specified is not used by any other process.

yarn test

Production build

Compiles the TypeScript source and creates a production ready build.

yarn build

Running the application

Starts the nodemon server and runs a development build. Ensure that the server port specified is not used by any other process.

yarn start:dev

API Specification

POST /couriers

Creates a courier. Requires a payload with an ID and max capacity. Example payload:

{
    "id": 1234,
    "max_capacity": 45
}

PUT /couriers/:id

Modifies an existing courier with the given ID. Requires a payload with an ID and max capacity. Example payload:

{
    "id": 1234,
    "max_capacity": 45
}

DELETE /couriers/:id

Deletes an existing courier with the given ID.

GET /couriers/lookup

Retrieve all couriers with a given max capacity. The max capacity can be specified as a query parameter, like so: /couriers/lookup?capacity_required=45. Without a specified max capacity, the value is inferred to be 0.

Response contains an array of couriers. Example response:

[
	{
		"id": 1232,
		"max_capacity": 30
	},
	{
		"id": 1233,
		"max_capacity": 40
	},
	{
		"id": 1234,
		"max_capacity": 50
	}
]