Fix chained .bind of Server Actions

packages/next/src/build/webpack/loaders/next-flight-loader/action-proxy.ts

@@ -4,27 +4,34 @@ export default function createActionProxy(
   action: any,
   originalAction?: any
 ) {
-  action.$$typeof = Symbol.for('react.server.reference')
-  action.$$id = id
-  action.$$bound = bound
+  function bindImpl(this: any, _: any, ...boundArgs: any[]) {
+    const currentAction = this
 
-  action.bind = function (_: any, ...boundArgs: any[]) {
     const newAction = async function (...args: any[]) {
       if (originalAction) {
         return originalAction(newAction.$$bound.concat(args))
       } else {
         // In this case we're calling the user-defined action directly.
-        return action(...newAction.$$bound, ...args)
+        return currentAction(...newAction.$$bound, ...args)
       }
     }
 
     for (const key of ['$$typeof', '$$id', '$$FORM_ACTION']) {
       // @ts-ignore
-      newAction[key] = action[key]
+      newAction[key] = currentAction[key]
     }
+
     // Rebind args
-    newAction.$$bound = (action.$$bound || []).concat(boundArgs)
+    newAction.$$bound = (currentAction.$$bound || []).concat(boundArgs)
+
+    // Assign bind method
+    newAction.bind = bindImpl.bind(newAction)
 
     return newAction
   }
+
+  action.$$typeof = Symbol.for('react.server.reference')
+  action.$$id = id
+  action.$$bound = bound
+  action.bind = bindImpl.bind(action)
 }

test/e2e/app-dir/actions/app-action.test.ts

@@ -123,6 +123,16 @@ createNextDescribe(
       }, '/header?result=122')
     })
 
+    it('should support chained .bind', async () => {
+      const browser = await next.browser('/server')
+
+      await browser.elementByCss('#add3').click()
+
+      await check(() => {
+        return browser.eval('window.location.pathname + window.location.search')
+      }, '/header?result=6')
+    })
+
     it('should support notFound (javascript disabled)', async () => {
       const browser = await next.browser('/server', {
         // TODO we should also test this with javascript on but not-found is not implemented yet.

test/e2e/app-dir/actions/app/server/form.js

@@ -34,6 +34,11 @@ export default function Form() {
     redirect('/header?result=' + (a + b + Number(formData.get('n'))))
   }
 
+  async function add3(a, b, c) {
+    'use server'
+    redirect('/header?result=' + (a + b + c))
+  }
+
   return (
     <>
       <hr />
@@ -66,6 +71,16 @@ export default function Form() {
           -1
         </button>
       </form>
+      <hr />
+      <form>
+        <button
+          type="submit"
+          id="add3"
+          formAction={add3.bind(null, 1).bind(null, 2).bind(null, 3)}
+        >
+          add3
+        </button>
+      </form>
     </>
   )
 }