Express example

This example will not run! Some parts are not implemented.

This API specific Express app example is demonstrating in my opinion a good architecture.

You can also read these slides for presentation called "Good Express.js Architecture":

• PDF with speaker notes
• PDF without speaker notes

Note: the terminology in this exampls is a bit different than in the slides. controller = endpoint = http-layer and service = core = business logic.

Here's how the Express API application has been architectured in the example:

Good with this setup:

• Your code can leverage Promises

• Testable

  • Express app instance can be created with a function

  • Router instance can be created with a function

  • Core methods are testable. This would allow you to write some lower level tests.

    Note: even though they are testable, usually you get the best ROI by testing with real HTTP API calls. In other words: put your express app running locally, init db to certain state, and fire http requests to localhost with e.g. supertest lib.

• Provides a minimal but nice "frame" around your development with separation of concerns

• Error handling is done in one place, in the error-handling middlewares defined in app.js

• Your request handling code can throw errors and they will be handled at the app level

  No need to repeat the next(err) pattern in all your request handlers.