no-vitest-unstub-envs-false

Disallow test.unstubEnvs: false in shared Vitest config.

Rule catalog ID: R056

Targeted pattern scope

• vitest.config.*
• vitest.workspace.*
• vite.config.* when Vitest test options are configured
• test.unstubEnvs

What this rule reports

This rule reports explicit test.unstubEnvs: false assignments in supported config files.

Why this rule exists

Stubbed environment variables should be restored between tests to avoid state leakage across suites. Disabling env unstubbing can create order-dependent behavior.

❌ Incorrect

import { defineConfig } from "vitest/config";

export default defineConfig({
    test: {
        unstubEnvs: false,
    },
});

✅ Correct

import { defineConfig } from "vitest/config";

export default defineConfig({
    test: {
        unstubEnvs: true,
    },
});

Behavior and migration notes

• this rule checks static boolean assignments only
• it targets committed config files, not arbitrary source modules

ESLint flat config example

import vite from "@typpi/eslint-plugin-vite";

export default [vite.configs.strict, vite.configs.vitest];

When not to use it

Disable this rule only if env stubbing lifecycle is handled externally and this flag is intentionally false.

Package documentation

• Vitest config reference

Further reading

• no-vitest-unstub-globals-false