fix: allow expandable env vars to reference any non-expandable env vars

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

@@ -39,6 +39,17 @@ describe('loadEnv', () => {
       `)
   })
 
+  test('override 2', () => {
+    expect(loadEnv('development2', join(__dirname, './env')))
+      .toMatchInlineSnapshot(`
+        {
+          "VITE_APP_BASE_ROUTE": "source",
+          "VITE_APP_BASE_URL": "source",
+          "VITE_SOURCE": "source",
+        }
+      `)
+  })
+
   test('VITE_USER_NODE_ENV', () => {
     loadEnv('development', join(__dirname, './env'))
     expect(process.env.VITE_USER_NODE_ENV).toEqual(undefined)

packages/vite/src/node/__tests__/env/.env.development2

@@ -0,0 +1,2 @@
+VITE_SOURCE=source
+VITE_APP_BASE_ROUTE=$VITE_SOURCE

packages/vite/src/node/env.ts

@@ -29,7 +29,7 @@ export function loadEnv(
   const env: Record<string, string> = {}
   const envFiles = getEnvFilesForMode(mode, envDir)
 
-  const parsed = Object.fromEntries(
+  let parsed = Object.fromEntries(
     envFiles.flatMap((filePath) => {
       if (!tryStatSync(filePath)?.isFile()) return []
 
@@ -49,6 +49,8 @@ export function loadEnv(
     process.env.BROWSER_ARGS = parsed.BROWSER_ARGS
   }
 
+  parsed = reorderEnvs(parsed)
+
   // let environment variables use each other. make a copy of `process.env` so that `dotenv-expand`
   // doesn't re-assign the expanded values to the global `process.env`.
   const processEnv = { ...process.env } as DotenvPopulateInput
@@ -83,3 +85,27 @@ export function resolveEnvPrefix({
   }
   return envPrefix
 }
+
+// https://github.com/motdotla/dotenv-expand/blob/6af96d46a28db30779bec90b6e9f40a98028a735/lib/main.js#L10C17-L10C73
+const dotEnvExpandRE = /(?<!\\)\$\{[^{}]+\}|(?<!\\)\$[A-Za-z_]\w*/
+const isExpandable = (value: string) => dotEnvExpandRE.test(value)
+
+/**
+ * Reorder env keys so that env vars that are expandable are last
+ *
+ * This is to make all expandable variable possible to reference non-expandable variables
+ */
+function reorderEnvs(input: Record<string, string>) {
+  return Object.fromEntries(
+    Object.entries(input).sort(([, a], [, b]) => {
+      const aIsExpandable = isExpandable(a)
+      const bIsExpandable = isExpandable(b)
+      if (
+        (aIsExpandable && bIsExpandable) ||
+        (!aIsExpandable && !bIsExpandable)
+      )
+        return 0
+      return aIsExpandable ? 1 : -1
+    }),
+  )
+}