Counter

A simple, complete ExpressJS app which counts upwards. This can be used as a base for designing new apps with dependencies, database connections, testing, and linting already configured.

Requirements

• NodeJS
• NPM
• SQLite 3 installed, or a PostgreSQL database

Installation

Install the project's dependencies:

$ npm install

Configure the PostgreSQL database:

$ psql -c 'create database counter;' -U <pg_user> -h <pg_host> -p <pg_port>
$ export PG_CONNECTION_STRING=postgres://<pg_user>@<pg_host>:<pg_port>/counter
$ export NODE_ENV=production
$ export PORT=<counter_port>
$ npm run migrations

Finally, run the application:

$ npm start

API

The API consists of 3 simple endpoints, all on the base path:

GET

$ curl -X GET http://<host>:<port>/

This will return a JSON object with two fields: count will contain the current state of the counter, and README contains a link back to this repository.

POST

$ curl -X POST http://<host>:<port>/

Although this is a POST response, no body is expected (although no error will be thrown if one is provided). A 204 No Content response will be returned, and the counter will be incremented for further GET requests.

DELETE

$ curl -X DELETE http://<host>:<port>/ -H 'Authorization: bearer {"active": true, "sub": "user"}'

Note that this endpoint requires a bearer token to be passed. If one is not provided, a 401 Unauthorized will be returned. However, no authentication is performed on the token; simply having a "sub", and an "active" value of true, is sufficient.

A 204 No Content response will be returned, and the counter will be reset to 0 for further GET requests.

Development

Testing

To run the tests, use:

$ npm test

However, to only run a subset of the tests, use:

$ npm test -- -g <Test description to search for>

This performs a search similar to grep against the descriptions given in describe() or it() calls.

This project also has linting, using both JSHint and ESLint.

$ npm run linter

To run the linters followed by tests, use the LATTE (Lint and Thoroughly Test Everything) command:

$ npm run latte

Running in Development

First, set the environment to development:

$ export NODE_ENV=development

Then, run migrations. In development, this will automatically create a SQLite database file.

$ npm run migrations

Use "devel" instead of "start"; this is a convenience that will automatically restart the server whenever the source files are changed.

$ npm run devel

Using PostgreSQL

If you wish to test the PostgreSQL integration during development, both the live deployment and tests can be run against a PostgreSQL database.

To run the server against a PostgreSQL database:

$ export NODE_ENV=development_pg
$ export PG_CONNECTION_STRING=postgres://<pg_user>@<pg_host>:<pg_port>/counter
$ npm run migrations
$ npm run devel

To run the tests against a PostgreSQL database:

$ export TEST_PG_CONNECTION_STRING=postgres://<pg_user>@<pg_host>:<pg_port>/counter
$ npm run test_pg

License

MIT © Morgan Patch 2020