feat: warn if envPrefix contains spaces

packages/vite/src/node/__tests__/config.spec.ts

@@ -632,9 +632,16 @@ describe('resolveEnvPrefix', () => {
     expect(() => resolveEnvPrefix(config)).toThrow()
   })
 
+  test(`throw error if envPrefix contains whitespace`, () => {
+    let config: UserConfig = { envPrefix: 'WITH SPACE' }
+    expect(() => resolveEnvPrefix(config)).toThrow()
+    config = { envPrefix: ['CUSTOM_', 'ANOTHER SPACE'] }
+    expect(() => resolveEnvPrefix(config)).toThrow()
+  })
+
   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_'])
   })
 })
 

packages/vite/src/node/env.ts

@@ -99,5 +99,10 @@ export function resolveEnvPrefix({
       `envPrefix option contains value '', which could lead unexpected exposure of sensitive information.`,
     )
   }
+  if (envPrefix.some((prefix) => prefix.includes(' '))) {
+    throw new Error(
+      `envPrefix option contains values with whitespace, which could lead to unexpected behavior.`,
+    )
+  }
   return envPrefix
 }