refactor: move navigation.state to a route prop (#6)

example/StackNavigator.tsx

@@ -262,11 +262,11 @@ const StackRouter: Router<CommonAction | Action> = {
 };
 
 export function StackNavigator(props: Props) {
-  const { navigation, descriptors } = useNavigationBuilder(StackRouter, props);
+  const { state, descriptors } = useNavigationBuilder(StackRouter, props);
 
   return (
     <div style={{ position: 'relative' }}>
-      {navigation.state.routes.map((route, i) => (
+      {state.routes.map((route, i) => (
         <div
           key={route.key}
           style={{
@@ -297,10 +297,7 @@ export function StackNavigator(props: Props) {
           boxShadow: '0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23)',
         }}
       >
-        {
-          descriptors[navigation.state.routes[navigation.state.index].key]
-            .options.title
-        }
+        {descriptors[state.routes[state.index].key].options.title}
       </div>
     </div>
   );

example/TabNavigator.tsx

@@ -184,18 +184,18 @@ const TabRouter: Router<Action | CommonAction> = {
 };
 
 export function TabNavigator(props: Props) {
-  const { navigation, descriptors } = useNavigationBuilder(TabRouter, props);
+  const { state, descriptors } = useNavigationBuilder(TabRouter, props);
 
   return (
     <div style={{ display: 'flex', flexDirection: 'row', height: '100%' }}>
-      {navigation.state.routes.map((route, i, self) => (
+      {state.routes.map((route, i, self) => (
         <div
           key={route.key}
           style={{
             width: `${100 / self.length}%`,
             padding: 10,
             borderRadius: 3,
-            backgroundColor: i === navigation.state.index ? 'tomato' : 'white',
+            backgroundColor: i === state.index ? 'tomato' : 'white',
           }}
         >
           {descriptors[route.key].render()}

example/index.tsx

@@ -3,8 +3,9 @@ import { render } from 'react-dom';
 import {
   NavigationContainer,
   CompositeNavigationProp,
-  NavigationHelpers,
   PartialState,
+  NavigationHelpers,
+  RouteProp,
 } from '../src';
 import Stack, { StackNavigationProp } from './StackNavigator';
 import Tab, { TabNavigationProp } from './TabNavigator';
@@ -26,14 +27,16 @@ const MyTab = Tab<TabParamList>();
 
 const First = ({
   navigation,
+  route,
 }: {
   navigation: CompositeNavigationProp<
     StackNavigationProp<StackParamList, 'first'>,
     NavigationHelpers<TabParamList>
   >;
+  route: RouteProp<StackParamList, 'first'>;
 }) => (
   <div>
-    <h1>First, {navigation.state.params.author}</h1>
+    <h1>First, {route.params.author}</h1>
     <button type="button" onClick={() => navigation.push('second')}>
       Push second
     </button>

src/NavigationBuilderContext.tsx

@@ -7,7 +7,7 @@ export type ChildActionListener = (
 ) => boolean;
 
 const NavigationBuilderContext = React.createContext<{
-  helpers?: NavigationHelpers;
+  navigation?: NavigationHelpers;
   onAction?: (action: NavigationAction, sourceNavigatorKey?: string) => boolean;
   addActionListener?: (listener: ChildActionListener) => void;
   removeActionListener?: (listener: ChildActionListener) => void;

src/SceneView.tsx

@@ -5,20 +5,20 @@ import {
   Route,
   NavigationState,
   NavigationHelpers,
-  ScreenProps,
+  RouteConfig,
 } from './types';
 import EnsureSingleNavigator from './EnsureSingleNavigator';
 
 type Props = {
-  screen: ScreenProps;
-  helpers: NavigationHelpers;
+  screen: RouteConfig;
+  navigation: NavigationHelpers;
   route: Route & { state?: NavigationState };
   getState: () => NavigationState;
   setState: (state: NavigationState) => void;
 };
 
 export default function SceneView(props: Props) {
-  const { screen, route, helpers, getState, setState } = props;
+  const { screen, route, navigation: helpers, getState, setState } = props;
 
   const navigation = React.useMemo(
     () => ({
@@ -35,9 +35,8 @@ export default function SceneView(props: Props) {
           ),
         });
       },
-      state: route,
     }),
-    [getState, helpers, route, setState]
+    [getState, helpers, route.key, setState]
   );
 
   const getCurrentState = React.useCallback(() => {
@@ -79,11 +78,12 @@ export default function SceneView(props: Props) {
           // @ts-ignore
           render={screen.component || screen.children}
           navigation={navigation}
+          route={route}
         >
           {'component' in screen && screen.component !== undefined ? (
-            <screen.component navigation={navigation} />
+            <screen.component navigation={navigation} route={route} />
           ) : 'children' in screen && screen.children !== undefined ? (
-            screen.children({ navigation })
+            screen.children({ navigation, route })
           ) : null}
         </StaticContainer>
       </EnsureSingleNavigator>

src/Screen.tsx

@@ -1,6 +1,6 @@
-import { ScreenProps } from './types';
+import { RouteConfig } from './types';
 
-export default function Screen(_: ScreenProps) {
+export default function Screen(_: RouteConfig) {
   /* istanbul ignore next */
   return null;
 }

src/__tests__/index.test.tsx

@@ -93,11 +93,9 @@ beforeEach(() => (MockRouter.key = 0));
 
 it('initializes state for a navigator on navigation', () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const FooScreen = (props: any) => {
@@ -148,11 +146,9 @@ it('initializes state for a navigator on navigation', () => {
 
 it('rehydrates state for a navigator on navigation', () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const BarScreen = (props: any) => {
@@ -195,11 +191,9 @@ it('rehydrates state for a navigator on navigation', () => {
 
 it('initializes state for nested navigator on navigation', () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const TestScreen = (props: any) => {
@@ -255,11 +249,9 @@ it('initializes state for nested navigator on navigation', () => {
 
 it("doesn't update state if nothing changed", () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const FooScreen = (props: any) => {
@@ -287,11 +279,9 @@ it("doesn't update state if nothing changed", () => {
 
 it("doesn't update state if action wasn't handled", () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const FooScreen = (props: any) => {
@@ -319,11 +309,9 @@ it("doesn't update state if action wasn't handled", () => {
 
 it('cleans up state when the navigator unmounts', () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const FooScreen = (props: any) => {
@@ -383,22 +371,15 @@ it("lets parent handle the action if child didn't", () => {
   };
 
   const ParentNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(
-      ParentRouter,
-      props
-    );
+    const { state, descriptors } = useNavigationBuilder(ParentRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const ChildNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const TestScreen = (props: any) => {
@@ -444,11 +425,9 @@ it("lets parent handle the action if child didn't", () => {
 
 it('allows arbitrary state updates by dispatching a function', () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const FooScreen = (props: any) => {
@@ -490,11 +469,9 @@ it('allows arbitrary state updates by dispatching a function', () => {
 
 it('updates route params with setParams', () => {
   const TestNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(MockRouter, props);
+    const { state, descriptors } = useNavigationBuilder(MockRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   let setParams: (params: object) => void = () => undefined;

src/__tests__/useOnChildUpdate.test.tsx

@@ -37,25 +37,17 @@ it("lets children handle the action if parent didn't", () => {
   };
 
   const ChildNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(
-      ChildRouter,
-      props
-    );
+    const { state, descriptors } = useNavigationBuilder(ChildRouter, props);
 
-    return descriptors[
-      navigation.state.routes[navigation.state.index].key
-    ].render();
+    return descriptors[state.routes[state.index].key].render();
   };
 
   const ParentNavigator = (props: any) => {
-    const { navigation, descriptors } = useNavigationBuilder(
-      ParentRouter,
-      props
-    );
+    const { state, descriptors } = useNavigationBuilder(ParentRouter, props);
 
     return (
       <React.Fragment>
-        {navigation.state.routes.map(route => descriptors[route.key].render())}
+        {state.routes.map(route => descriptors[route.key].render())}
       </React.Fragment>
     );
   };

src/createNavigator.tsx

@@ -1,5 +1,5 @@
 import * as React from 'react';
-import { ParamListBase, ScreenProps, TypedNavigator } from './types';
+import { ParamListBase, RouteConfig, TypedNavigator } from './types';
 import Screen from './Screen';
 
 export default function createNavigator<N extends React.ComponentType<any>>(
@@ -12,7 +12,7 @@ export default function createNavigator<N extends React.ComponentType<any>>(
     return {
       Navigator: RawNavigator,
       Screen: Screen as React.ComponentType<
-        ScreenProps<ParamList, keyof ParamList>
+        RouteConfig<ParamList, keyof ParamList>
       >,
     };
   };

src/types.tsx

@@ -204,14 +204,6 @@ export type NavigationProp<
   ParamList extends ParamListBase,
   RouteName extends keyof ParamList
 > = NavigationHelpers<ParamList> & {
-  /**
-   * State for the child navigator.
-   */
-  state: Omit<Route<RouteName>, 'params'> &
-    (ParamList[RouteName] extends undefined
-      ? {}
-      : { params: ParamList[RouteName] });
-
   /**
    * Update the param object for the route.
    * The new params will be shallow merged with the old one.
@@ -221,6 +213,19 @@ export type NavigationProp<
   setParams(params: ParamList[RouteName]): void;
 };
 
+export type RouteProp<
+  ParamList extends ParamListBase,
+  RouteName extends keyof ParamList
+> = Omit<Route<RouteName>, 'params'> &
+  (ParamList[RouteName] extends undefined
+    ? {}
+    : {
+        /**
+         * Params for this route
+         */
+        params: ParamList[RouteName];
+      });
+
 export type CompositeNavigationProp<
   A extends NavigationHelpers<ParamListBase>,
   B extends NavigationHelpers<ParamListBase>
@@ -251,7 +256,7 @@ export type Options = {
   [key: string]: any;
 };
 
-export type ScreenProps<
+export type RouteConfig<
   ParamList extends ParamListBase = ParamListBase,
   RouteName extends keyof ParamList = string
 > = {
@@ -295,5 +300,5 @@ export type TypedNavigator<
       initialRouteName?: keyof ParamList;
     }
   >;
-  Screen: React.ComponentType<ScreenProps<ParamList, keyof ParamList>>;
+  Screen: React.ComponentType<RouteConfig<ParamList, keyof ParamList>>;
 };

src/useDescriptors.tsx

@@ -6,7 +6,7 @@ import {
   NavigationHelpers,
   NavigationState,
   ParamListBase,
-  ScreenProps,
+  RouteConfig,
 } from './types';
 import SceneView from './SceneView';
 import NavigationBuilderContext, {
@@ -15,8 +15,8 @@ import NavigationBuilderContext, {
 
 type Options = {
   state: NavigationState | PartialState;
-  screens: { [key: string]: ScreenProps<ParamListBase, string> };
-  helpers: NavigationHelpers<ParamListBase>;
+  screens: { [key: string]: RouteConfig<ParamListBase, string> };
+  navigation: NavigationHelpers<ParamListBase>;
   onAction: (action: NavigationAction, sourceNavigatorKey?: string) => boolean;
   getState: () => NavigationState;
   setState: (state: NavigationState) => void;
@@ -34,7 +34,7 @@ const EMPTY_OPTIONS = Object.freeze({});
 export default function useDescriptors({
   state,
   screens,
-  helpers,
+  navigation,
   onAction,
   getState,
   setState,
@@ -44,13 +44,19 @@ export default function useDescriptors({
 }: Options) {
   const context = React.useMemo(
     () => ({
-      helpers,
+      navigation,
       onAction,
       addActionListener,
       removeActionListener,
       onChildUpdate,
     }),
-    [helpers, onAction, onChildUpdate, addActionListener, removeActionListener]
+    [
+      navigation,
+      onAction,
+      onChildUpdate,
+      addActionListener,
+      removeActionListener,
+    ]
   );
 
   return state.routes.reduce(
@@ -62,7 +68,7 @@ export default function useDescriptors({
           return (
             <NavigationBuilderContext.Provider value={context}>
               <SceneView
-                helpers={helpers}
+                navigation={navigation}
                 route={route}
                 screen={screen}
                 getState={getState}

src/useNavigationBuilder.tsx

@@ -5,7 +5,7 @@ import useRegisterNavigator from './useRegisterNavigator';
 import useDescriptors from './useDescriptors';
 import useNavigationHelpers from './useNavigationHelpers';
 import useOnAction from './useOnAction';
-import { Router, NavigationState, ScreenProps } from './types';
+import { Router, NavigationState, RouteConfig } from './types';
 import useOnChildUpdate from './useOnChildUpdate';
 import useChildActionListeners from './useChildActionListeners';
 
@@ -29,7 +29,7 @@ export default function useNavigationBuilder(
     }
 
     if (React.isValidElement(child) && child.type === Screen) {
-      return child.props as ScreenProps;
+      return child.props as RouteConfig;
     }
 
     throw new Error(
@@ -42,10 +42,10 @@ export default function useNavigationBuilder(
     .filter(Boolean)
     .reduce(
       (acc, curr) => {
-        acc[curr!.name] = curr as ScreenProps;
+        acc[curr!.name] = curr as RouteConfig;
         return acc;
       },
-      {} as { [key: string]: ScreenProps }
+      {} as { [key: string]: RouteConfig }
     );
 
   const routeNames = Object.keys(screens);
@@ -140,22 +140,17 @@ export default function useNavigationBuilder(
     setState,
   });
 
-  const helpers = useNavigationHelpers({
+  const navigation = useNavigationHelpers({
     onAction,
     getState,
     setState,
     actionCreators: router.actionCreators,
   });
 
-  const navigation = React.useMemo(() => ({ ...helpers, state }), [
-    helpers,
-    state,
-  ]);
-
   const descriptors = useDescriptors({
     state,
     screens,
-    helpers,
+    navigation,
     onAction,
     getState,
     setState,
@@ -165,6 +160,7 @@ export default function useNavigationBuilder(
   });
 
   return {
+    state,
     navigation,
     descriptors,
   };

src/useNavigationHelpers.tsx

@@ -21,7 +21,7 @@ export default function useNavigationHelpers({
   setState,
   actionCreators,
 }: Options) {
-  const { helpers: parentNavigationHelpers } = React.useContext(
+  const { navigation: parentNavigationHelpers } = React.useContext(
     NavigationBuilderContext
   );