Redux: Writing a Counter Reducer with Tests

Would you mind explaining more as to why you define counter as a const and an arrow function? What is meant by it has clearer semantics? Thanks so much, really enjoying the series so far!

Nathaniel,

For historical reasons JS function declarations have weird semantics. "function" is not block-scoped (that it, behaves like "var" rather than like ES6 "let" or "const"), it is hoisted (a very weird thing to cloud beginners' heads with), it has "this" context which is frustrating to explain when you're just teaching some library's API, etc.

See also:

https://medium.com/@ryanflorence/functions-without-function-bc356ed34a2f

https://twitter.com/sebmarkbage/status/638531311477522433

Which library are you using for expect?

Figured out through later episodes it is loaded through as a script tag on the HTML src="https://wzrd.in/standalone/expect@latest". Loving the series so far, same architecture as ELM but with JS!

If anyone wondering:

https://github.com/mjackson/expect

Is expect a thing from expect.js that I need to npm install? Also what environment should I use for this mini tutorial series?