fix(alias): normalize alias behavior when there is ending slash

ref #1363

docs/guide/migration.md

@@ -38,11 +38,11 @@
 
 ## Alias Behavior Change
 
-[`alias`](/config/#alias) is now being passed to `@rollup/plugin-alias` and no longer require start/ending slashes. The behavior is now a direct replacement, so 1.0-style directory aliases now require an ending slash:
+[`alias`](/config/#alias) is now being passed to `@rollup/plugin-alias` and no longer require start/ending slashes. The behavior is now a direct replacement, so 1.0-style directory alias key should remove the ending slash:
 
 ```diff
 - alias: { '/@foo/': path.resolve(__dirname, 'some-special-dir') }
-+ alias: { '/@foo/': path.resolve(__dirname, 'some-special-dir') + '/' }
++ alias: { '/@foo': path.resolve(__dirname, 'some-special-dir') }
 ```
 
 Alternatively, you can use the `[{ find: RegExp, replacement: string }]` option format for more precise control.

packages/vite/package.json

@@ -26,6 +26,7 @@
   },
   "homepage": "https://github.com/vitejs/vite/tree/main/#readme",
   "scripts": {
+    "predev": "rimraf dist",
     "dev": "run-p dev-client dev-node",
     "dev-client": "tsc -w --incremental --p src/client",
     "dev-node": "tsc -w --incremental --p src/node",

packages/vite/src/node/config.ts

@@ -283,12 +283,28 @@ function mergeAlias(a: AliasOptions = [], b: AliasOptions = []): Alias[] {
 }
 
 function normalizeAlias(o: AliasOptions): Alias[] {
-  return isObject(o)
-    ? Object.keys(o).map((find) => ({
-        find,
-        replacement: (o as any)[find]
-      }))
-    : o
+  return Array.isArray(o)
+    ? o.map(normalizeSingleAlias)
+    : Object.keys(o).map((find) =>
+        normalizeSingleAlias({
+          find,
+          replacement: (o as any)[find]
+        })
+      )
+}
+
+// https://github.com/vitejs/vite/issues/1363
+// work around https://github.com/rollup/plugins/issues/759
+function normalizeSingleAlias({ find, replacement }: Alias): Alias {
+  if (
+    typeof find === 'string' &&
+    find.endsWith('/') &&
+    replacement.endsWith('/')
+  ) {
+    find = find.slice(0, find.length - 1)
+    replacement = replacement.slice(0, replacement.length - 1)
+  }
+  return { find, replacement }
 }
 
 export function sortUserPlugins(