A simple trick for your dotenv files

I'm sure most of you know and use dotenv files. They are great for storing app configs: everything that is likely to vary between deploys

MY_APP_KEY=supersecret

These app configs are stored in a convenient key/value pair in a dotenv file. But what may come as a surprise to you is that every value is a string

DAYS_UNTIL_DATA_DELETION=60
AWS_DISABLE=true

Both are in fact strings. Later on, when you will want to check if AWS is disabled, you will have to write this code (which I have seen over and over again in many projects)

if (process.env.AWS_DISABLE === "true") { ... } // what???

That is just silly! When faced with boolean values I always write them with yes/no instead of true/false.

Furthermore, I quote every value in the dotenv files to make sure that every developer that reads the file knows the values are strings.

Here is the result:

MY_APP_KEY="supersecret"
DAYS_UNTIL_DATA_DELETION="60"
AWS_DISABLE="yes"

Hope you enjoyed reading the article as much as I enjoyed writing it. And please do not store your boolean config values as strings. Give the yes/no option a try.

Photo by Tekton on Unsplash

Comments

[tshammer]

What I do is define an array of false-ish strings then use a ternary operator to convert the .env variable value to a boolean

const falsey = [ "false", "no", "0", "disabled", "disable" ]
dotenv.config()
const DEBUG=process.env.DEBUG ? (falsey.includes(process.env.DEBUG) ? false:true) : false

Nice and concise with few lines of code.