fix: support legacy goBack method

packages/compat/src/NavigationActions.tsx

@@ -1,4 +1,4 @@
-import { CommonActions } from '@react-navigation/core';
+import { CommonActions, NavigationState } from '@react-navigation/core';
 
 export function navigate({
   routeName,
@@ -24,14 +24,14 @@ export function navigate({
   });
 }
 
-export function back(options?: { key: null | never }): CommonActions.Action {
-  if (options !== undefined && options.key != null) {
-    throw new Error(
-      "The legacy `back` action with a key is not supported. To go back from a specific route, you need to specify both route key and the navigator's state key in the action: `{ ...CommonActions.goBack(), source: route.key, target: state.key }`."
-    );
-  }
-
-  return CommonActions.goBack();
+export function back(options?: { key?: null | string }) {
+  return options && options.key != null
+    ? (state: NavigationState) => ({
+        ...CommonActions.goBack(),
+        source: options.key,
+        target: state.key,
+      })
+    : CommonActions.goBack();
 }
 
 export function setParams({

packages/compat/src/createCompatNavigationProp.tsx

@@ -26,16 +26,24 @@ export default function createCompatNavigationProp<
 ) {
   return {
     ...navigation,
-    ...Object.entries(helpers).reduce<{ [key: string]: Function }>(
-      (acc, [name, method]: [string, Function]) => {
-        if (name in navigation) {
-          acc[name] = (...args: any[]) => navigation.dispatch(method(...args));
-        }
+    ...Object.entries(helpers).reduce<{
+      [key: string]: (...args: any[]) => void;
+    }>((acc, [name, method]) => {
+      if (name in navigation) {
+        acc[name] = (...args: any[]) => {
+          // @ts-ignore
+          const payload = method(...args);
 
-        return acc;
-      },
-      {}
-    ),
+          navigation.dispatch(
+            typeof payload === 'function'
+              ? payload(navigation.dangerouslyGetState())
+              : payload
+          );
+        };
+      }
+
+      return acc;
+    }, {}),
     original: navigation,
     addListener(type: EventName, callback: () => void) {
       let unsubscribe: () => void;

packages/compat/src/helpers.tsx

@@ -29,10 +29,8 @@ export function navigate(
   return NavigationActions.navigate(options);
 }
 
-export function goBack(fromKey?: null | never) {
-  return NavigationActions.back(
-    fromKey !== undefined ? { key: fromKey } : undefined
-  );
+export function goBack(fromKey?: null | string) {
+  return NavigationActions.back({ key: fromKey });
 }
 
 export function setParams(params: object) {