No Exceptions

This is code exercise aiming to learn to get rid of exceptional code, that is, code that relies on exception handling.

The 'incoming boundary' of the capability is signup-to-session.js. The calling code currently expects that this code will throw errors if it's not following the 'happy flow'.

For this contract, there exists an Acceptance Test that tests all the errors thrown and the happy case.

Exercise flow:

Plan ahead.

1. Discuss for 5 minutes what are the consequences of code where exceptions are thrown.
2. Let's gather our learnings
3. There's two approaches on this: bottom-up vs 'top-down'.
   • bottom up: meaning starting at session.js
   • start at 'incoming boundary' signup-to-session.js
4. What are the implications of choosing first of the other.

Start coding

Make sure that you keep on green. Existing tests can be red for only a brief moment. If you want extra challenge, do this with 'parallel change' approach (also known as 'expand-migrate-contract')

For extra challenge:

• Use 'expand-migrate-contract' approach (if it's known for you.)
• make sure the existing tests never break.

Getting started

Installation:

1. Run yarn or npm install, whichever you prefer (yarn is used by default, but you may choose what you want)
2. Run tests (yarn test or npm run test) and see all tests green.

Optional, eslint rules

1. You can check that eslint is configured by running yarn lint that runs linting - it should have no issues.

Questions?

• should the 'user not found' scenario be actually a 'UserNotFoundError' - I see that a lot in production codes.