For our project, let's use the index name hobnob for development, and test for testing. Instead of hard-coding the index name into our code, we can use an environment variable to set it dynamically. Therefore, in both our application and test code, replace all instances of index: 'hobnob' with index: process.env.ELASTICSEARCH_INDEX.
Currently, we are using the dotenv-cli package to load our environment variables. As it turns out, the package also provides an -e flag that allows us to load multiple files. This means we can store default environment variables in our .env file, and create a new test.env to store testing-specific environment variables, which will override the defaults.
Therefore, add the following ...
