fix(vitest): make env.SSR consistent between different pools (#6616)

Author: sheremet-va

packages/vitest/src/runtime/runVmTests.ts

@@ -45,6 +45,10 @@ export async function run(
     KNOWN_ASSET_TYPES.forEach((type) => {
       _require.extensions[`.${type}`] = resolveAsset
     })
+    process.env.SSR = ''
+  }
+  else {
+    process.env.SSR = '1'
   }
 
   // @ts-expect-error not typed global for patched timers

test/core/test/environments/jsdom.spec.ts

@@ -101,3 +101,7 @@ test('jsdom global is exposed', () => {
   dom.reconfigure({ url: 'https://examples.new.com' })
   expect(location.href).toBe('https://examples.new.com/')
 })
+
+test('ssr is disabled', () => {
+  expect(import.meta.env.SSR).toBe(false)
+})

test/core/test/environments/node.spec.ts

@@ -9,3 +9,7 @@ test.runIf(nodeMajor > 16)('url correctly creates an object', () => {
     URL.createObjectURL(new Blob([]))
   }).not.toThrow()
 })
+
+test('ssr is enabled', () => {
+  expect(import.meta.env.SSR).toBe(true)
+})

test/core/vitest.workspace.ts

@@ -1,4 +1,4 @@
-import type { Pool } from 'vitest'
+import type { Pool } from 'vitest/node'
 import { defineWorkspace } from 'vitest/config'
 
 function project(pool: Pool) {