Accessing .env variables in a Jest + Vite framework.

Have you ever experiences issues during testing using JEST in a React ts + Vite framework.

When I was developing an application in this environment , during testing there is an error showing import.meta is not defined.
The reason for this error was because Vite uses import.meta for accessing the environment variables, but JEST is built in a Node.js environment, so it only uses process.env for accessing the environment variables.That's why JEST can't identify Import.meta and giving the error on testing.

So I will share the way I solved this issue:
I used the method of environment separation for both JEST and Vite.

So for the application , I created a function to access environment variables for the application using import.meta like this:

## env.app.ts
export const getLoginMode = () => {
  return import.meta.env.VITE_ENV_LOGIN_MODE;
};

Then I created an index file for this function like this:

## env.ts
export * from "./env.app";

Then I used it in component in my application like this:

## component.tsx
import { getLoginMode } from "@/path_to_env/env";
const loginMode = getLoginMode();

Thus the application works fine.

Now for the testing part using JEST , we create an alternate function using the process.env like this:

## env.jest.ts
export const getLoginMode = () => {
  return process.env.VITE_ENV_LOGIN_MODE;
};

Then in Jest.config.ts file we change path.of index file env.ts to map to env.jest.ts like this:

## jest.config.ts
moduleNameMapper: {
    "^@/path_to_env/env$": "<rootDir>/path_to_jest_env/env.jest.ts",
},

So what happens here clearly is that during the normal working of application in Vite , the index file env.ts maps to function in env.app.ts which uses import.meta.Thus the application works correctly.But during testing , we map the path of index file to map to env.jest.ts. Thus jest on accessing the function using env.ts will get the function in env.jest.ts which uses process.env.Thus the issue with the Jest is also solved.

Thus we can have the testing using jest in the vite environment.

You can also share your own methods to solve this issue.