feat: warn if envPrefix contains spaces (#21292)

btea · bluwy · graphite-app[bot] · web-flow · commit 9fcde3c87089 · 2026-01-15T12:46:55.000+09:00
Co-authored-by: Bjorn Lu &lt;bjornlu.dev@gmail.com&gt;
Co-authored-by: graphite-app[bot] &lt;96075541+graphite-app[bot]@users.noreply.github.com&gt;
Co-authored-by: 翠 &lt;green@sapphi.red&gt;
diff --git a/packages/vite/src/node/__tests__/config.spec.ts b/packages/vite/src/node/__tests__/config.spec.ts
@@ -1,7 +1,7 @@
 import http from 'node:http'
 import path from 'node:path'
 import fs from 'node:fs'
-import { afterEach, describe, expect, test } from 'vitest'
+import { afterEach, describe, expect, test, vi } from 'vitest'
 import type { InlineConfig, PluginOption } from '..'
 import type { UserConfig, UserConfigExport } from '../config'
 import { defineConfig, loadConfigFromFile, resolveConfig } from '../config'
@@ -632,9 +632,22 @@ describe('resolveEnvPrefix', () => {
     expect(() => resolveEnvPrefix(config)).toThrow()
   })
 
+  test(`show a warning message if envPrefix contains a whitespace`, () => {
+    const consoleWarnSpy = vi
+      .spyOn(console, 'warn')
+      .mockImplementation(() => {})
+    let config: UserConfig = { envPrefix: 'WITH SPACE' }
+    resolveEnvPrefix(config)
+    expect(consoleWarnSpy).toHaveBeenCalled()
+    config = { envPrefix: ['CUSTOM_', 'ANOTHER SPACE'] }
+    resolveEnvPrefix(config)
+    expect(consoleWarnSpy).toHaveBeenCalledTimes(2)
+    consoleWarnSpy.mockRestore()
+  })
+
   test('should work correctly for valid envPrefix value', () => {
-    const config: UserConfig = { envPrefix: [' ', 'CUSTOM_'] }
-    expect(resolveEnvPrefix(config)).toMatchObject([' ', 'CUSTOM_'])
+    const config: UserConfig = { envPrefix: ['CUSTOM_'] }
+    expect(resolveEnvPrefix(config)).toMatchObject(['CUSTOM_'])
   })
 })
 
diff --git a/packages/vite/src/node/env.ts b/packages/vite/src/node/env.ts
@@ -2,6 +2,7 @@ import fs from 'node:fs'
 import path from 'node:path'
 import { parse } from 'dotenv'
 import { type DotenvPopulateInput, expand } from 'dotenv-expand'
+import colors from 'picocolors'
 import { arraify, createDebugger, normalizePath, tryStatSync } from './utils'
 import type { UserConfig } from './config'
 
@@ -101,5 +102,13 @@ export function resolveEnvPrefix({
       `envPrefix option contains value '', which could lead unexpected exposure of sensitive information.`,
     )
   }
+  if (envPrefix.some((prefix) => /\s/.test(prefix))) {
+    // eslint-disable-next-line no-console
+    console.warn(
+      colors.yellow(
+        `[vite] Warning: envPrefix option contains values with whitespace, which does not work in practice.`,
+      ),
+    )
+  }
   return envPrefix
 }
