Prevents process.env from being accessed dynamically (expo/no-dynamic-env-var)

Expo's Metro config injects build settings that can be used in the client bundle via environment variables. The environment variables (process.env.*) are replaced with the appropriate values at build time. This means that process.env is not a standard JavaScript object, and dynamically accessing its values will break inlining of environment variables.

Rule Details

This rule aims to prevent users from encountering errors due to dynamically accessing variables from process.env.

Examples of incorrect code for this rule:

const myVar = process.env["MY_VAR"]


const dynamicVar = "MY_VAR";
const myVar = process.env[dynamicVar];

Examples of correct code for this rule:

const myVar = process.env.MY_VAR;

When Not To Use It

If you're not using Expo.

Further Reading

• Metro environment settings