define config fails for constants like process.env.FOO, but only if in both browser mode and a project #8887
Description
Describe the bug
define in the vitest config works.
It also works in browser mode.
It also works in a project.
It even works in a project that uses browser mode... unless the constant is named something like process.env.FOO. In the case where you have all 3 of those things (project, browser mode, define for a constant named process.env.FOO) it fails.
I know that sounds crazy, but I have a minimal reproduction!
Reproduction
Everything below is in that repo, ready to easily run, I'm just copying it here so the bug report is self contained.
This is the config causing trouble:
import { defineConfig } from "vitest/config";
import { playwright } from "@vitest/browser-playwright";
export default defineConfig({
test: {
projects: [
{
define: {
"process.env.FOO": JSON.stringify("BAR"),
},
test: {
name: "node",
include: ["src/test.ts"],
},
},
{
define: {
"process.env.FOO": JSON.stringify("BAR"),
},
test: {
name: "browser",
include: ["src/test.ts"],
browser: {
enabled: true,
headless: true,
provider: playwright(),
instances: [{ browser: "chromium" }],
screenshotFailures: false,
},
},
},
{
define: {
"process.FOO.FOO": JSON.stringify("BAR"),
},
test: {
name: "browser2",
include: ["src/test2.ts"],
browser: {
enabled: true,
headless: true,
provider: playwright(),
instances: [{ browser: "chromium" }],
screenshotFailures: false,
},
},
},
],
},
});And these are the test files:
src/test.ts:
import { expect, test } from "vitest";
test("process.env.FOO", () => {
expect(process.env.FOO).toBe("BAR");
});src/test2.ts:
import { expect, test } from "vitest";
test("process.FOO.FOO", () => {
expect(process.FOO.FOO).toBe("BAR");
});I think all those tests should pass, but instead the "browser" test fails:
FAIL browser (chromium) src/test.ts > process.env.FOO
ReferenceError: process is not defined
❯ src/test.ts:4:9
2|
3| test('process.env.FOO', () => {
4| expect(process.env.FOO).toBe("BAR")
| ^
5| })
If I take that project and move it to its own config file:
import { playwright } from "@vitest/browser-playwright";
import { defineConfig } from "vitest/config";
export default defineConfig({
define: {
"process.env.FOO": JSON.stringify("BAR"),
},
test: {
name: "browser",
include: ["src/test.ts"],
browser: {
enabled: true,
headless: true,
provider: playwright(),
instances: [{ browser: "chromium" }],
screenshotFailures: false,
},
},
});Then the test passes.
System Info
System:
OS: Linux 6.8 Ubuntu 24.04.3 LTS 24.04.3 LTS (Noble Numbat)
CPU: (8) x64 Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz
Memory: 12.57 GB / 31.13 GB
Container: Yes
Shell: 5.2.21 - /bin/bash
Binaries:
Node: 24.10.0 - /usr/bin/node
npm: 11.6.1 - /usr/bin/npm
pnpm: 10.20.0 - /home/user/.local/share/pnpm/pnpm
Browsers:
Chrome: 141.0.7390.107
Firefox: 144.0.2
Firefox Developer Edition: 144.0.2
npmPackages:
@vitest/browser-playwright: ^4.0.5 => 4.0.5
vitest: ^4.0.5 => 4.0.5Used Package Manager
pnpm
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- The provided reproduction is a minimal reproducible example of the bug.