The project is organized into folders according to the following path pattern src/<language>; so the JS code lives inside the src/js directory.

I have implemented three solutions:

1. A JS solution (src/js/main.js) that uses the reduce function to perform a recursive application of the sha256 operator.
2. Another JS solution (src/js/main-rec.js) that implements a recursive version of the verifyHash function
3. A Go lang implementation (src/go/main.go)

I have written a unit test for one of the JS implementation. However, it looks redundant as the actual test happens within the main module for each language and more specifically the main function. The module that contains the verifyHash includes both the implementation and the main function that acts as a unit against an existing merkle tree which we know is correct.

To run the JS implementation:

Go to src/js and type:

• node main.js
• node main-rec.js

To run the test:

• yarn install or npm install
• yarn test or npm run test

To run the Go implementation:

Go to src/go and type:

• go run main.go

There are no comments in the code because I tend to write tiny function that have a single responsibility and a self-explanatory name; thus additional comments can be sometimes confusing.