Make NavigationLegacyNavigator more testable.

Summary:- Move the logics that manage the routes stack into `NavigationLegacyNavigatorRouteStack`
- Add more unit tests for NavigationLegacyNavigatorRouteStack.
- Keep NavigationLegacyNavigator as a pure view as possible as we could.

Reviewed By: fkgozali

Differential Revision: D3060459

fb-gh-sync-id: 2c6802115c3f6ca5e396903f0d314ff54129524c
shipit-source-id: 2c6802115c3f6ca5e396903f0d314ff54129524c

Libraries/CustomComponents/NavigationExperimental/NavigationLegacyNavigator.js

@@ -45,7 +45,6 @@ const NavigatorSceneConfigs = require('NavigatorSceneConfigs');
 const React = require('react-native');
 const ReactComponentWithPureRenderMixin = require('ReactComponentWithPureRenderMixin');
 
-const invariant = require('fbjs/lib/invariant');
 const guid = require('guid');
 
 import type  {
@@ -129,20 +128,15 @@ class NavigationLegacyNavigator extends React.Component<any, Props, State> {
   }
 
   jumpTo(route: any): void {
-    const index = this._stack.indexOf(route);
-    invariant(
-      index > -1,
-      'Cannot jump to route that is not in the route stack'
-    );
-    this._jumpToIndex(index);
+    this._applyStack(this._stack.jumpTo(route));
   }
 
   jumpForward(): void {
-    this._jumpToIndex(this._stack.index + 1);
+    this._applyStack(this._stack.jumpForward());
   }
 
   jumpBack(): void {
-    this._jumpToIndex(this._stack.index - 1);
+    this._applyStack(this._stack.jumpBack());
   }
 
   push(route: any): void {
@@ -150,25 +144,11 @@ class NavigationLegacyNavigator extends React.Component<any, Props, State> {
   }
 
   pop(): void {
-    const stack = this._stack;
-    if (stack.size > 1) {
-      this._applyStack(stack.pop());
-    }
+    this._applyStack(this._stack.pop());
   }
 
   replaceAtIndex(route: any, index: number): void {
-    const stack = this._stack;
-
-    if (index < 0) {
-      index += stack.size;
-    }
-
-    if (index >= stack.size) {
-      // Nothing to replace.
-      return;
-    }
-
-    this._applyStack(stack.replaceAtIndex(index, route));
+    this._applyStack(this._stack.replaceAtIndex(index, route));
   }
 
   replace(route: any): void {
@@ -184,49 +164,27 @@ class NavigationLegacyNavigator extends React.Component<any, Props, State> {
   }
 
   popToRoute(route: any): void {
-    const stack = this._stack;
-    const nextIndex = stack.indexOf(route);
-    invariant(
-      nextIndex > -1,
-      'Calling popToRoute for a route that doesn\'t exist!'
-    );
-    this._applyStack(stack.slice(0, nextIndex + 1));
+    this._applyStack(this._stack.popToRoute(route));
   }
 
   replacePreviousAndPop(route: any): void {
-    const stack = this._stack;
-    const nextIndex = stack.index - 1;
-    if (nextIndex < 0) {
-      return;
-    }
-    this._applyStack(stack.replaceAtIndex(nextIndex, route).pop());
+    this._applyStack(this._stack.replacePreviousAndPop(route));
   }
 
   resetTo(route: any): void {
-    invariant(!!route, 'Must supply route');
-    this._applyStack(this._stack.slice(0).replaceAtIndex(0, route));
+    this._applyStack(this._stack.resetTo(route));
   }
 
   immediatelyResetRouteStack(routes: Array<any>): void {
-    const index = routes.length - 1;
-    const stack = new RouteStack(index, routes);
     // Immediately blow away all current scenes with a new key.
     this._key = guid();
-    this._applyStack(stack);
+    this._applyStack(this._stack.resetRoutes(routes));
   }
 
   getCurrentRoutes(): Array<any> {
     return this._stack.toArray();
   }
 
-  _jumpToIndex(index: number): void {
-    const stack = this._stack;
-    if (index < 0 || index >= stack.size) {
-      return;
-    }
-    this._applyStack(stack.jumpToIndex(index));
-  }
-
   // Lyfe cycle and private methods below.
 
   shouldComponentUpdate(nextProps: Object, nextState: Object): boolean {

Libraries/CustomComponents/NavigationExperimental/NavigationLegacyNavigatorRouteStack.js

@@ -1,5 +1,10 @@
 /**
- * Copyright 2004-present Facebook. All Rights Reserved.
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
  *
  * @providesModule NavigationLegacyNavigatorRouteStack
  * @flow
@@ -85,8 +90,7 @@ class RouteNode {
   }
 
   toNavigationState(): NavigationState {
-    const state: NavigationState = this;
-    return state;
+    return this;
   }
 }
 
@@ -114,7 +118,7 @@ class RouteStack {
 
     invariant(
       index > -1 && index <= routes.length - 1,
-      'index out of bound'
+      'RouteStack: index out of bound'
     );
 
 
@@ -187,7 +191,7 @@ class RouteStack {
     }
 
     for (let ii = 0, jj = this._routeNodes.length; ii < jj; ii++) {
-      let node = this._routeNodes[ii];
+      const node = this._routeNodes[ii];
       if (node.route === route) {
         return ii;
       }
@@ -230,16 +234,29 @@ class RouteStack {
    * excluding the last index in this stack.
    */
   pop(): RouteStack {
-    invariant(
-      this._routeNodes.length > 1,
-      'should not pop routeNodes stack to empty'
-    );
+    if (this._routeNodes.length <= 1) {
+      return this;
+    }
 
     // When popping, removes the rest of the routes past the current index.
     const routeNodes = this._routeNodes.slice(0, this._index);
     return this._update(routeNodes.length - 1, routeNodes);
   }
 
+  popToRoute(route: any): RouteStack {
+    const index = this.indexOf(route);
+    invariant(
+      index > -1,
+      'Calling popToRoute for a route that doesn\'t exist!'
+    );
+    return this.slice(0, index + 1);
+  }
+
+  jumpTo(route: any): RouteStack {
+    const index = this.indexOf(route);
+    return this.jumpToIndex(index);
+  }
+
   jumpToIndex(index: number): RouteStack {
     invariant(
       index > -1 && index < this._routeNodes.length,
@@ -249,6 +266,22 @@ class RouteStack {
     return this._update(index, this._routeNodes);
   }
 
+  jumpForward(): RouteStack {
+    const index = this._index + 1;
+    if (index >= this._routeNodes.length) {
+      return this;
+    }
+    return this._update(index, this._routeNodes);
+  }
+
+  jumpBack(): RouteStack {
+    const index = this._index - 1;
+    if (index < 0) {
+      return this;
+    }
+    return this._update(index, this._routeNodes);
+  }
+
   /**
    * Replace a route in the navigation stack.
    *
@@ -267,20 +300,59 @@ class RouteStack {
 
     invariant(this.indexOf(route) === -1, 'route must be unique');
 
+    const size = this._routeNodes.length;
     if (index < 0) {
-      index += this._routeNodes.length;
+      index += size;
     }
 
-    invariant(
-      index > -1 && index < this._routeNodes.length,
-      'replaceAtIndex: index out of bound'
-    );
+    if (index < 0 || index >= size) {
+      return this;
+    }
 
     const routeNodes = this._routeNodes.slice(0);
     routeNodes[index] = new RouteNode(route);
     return this._update(index, routeNodes);
   }
 
+  replacePreviousAndPop(route: any): RouteStack {
+    if (this._index < 1) {
+      // stack is too small.
+      return this;
+    }
+
+    const index = this.indexOf(route);
+    invariant(
+      index === -1 || index === this._index - 1,
+      'route already exists in the stack'
+    );
+
+    return this.replaceAtIndex(this._index - 1, route).popToRoute(route);
+  }
+
+  // Reset
+
+  /**
+   * Replace the current active route with a new route, and pops out
+   * the rest routes after it.
+   */
+  resetTo(route: any): RouteStack {
+    invariant(!isRouteEmpty(route), 'Must supply route');
+    const index = this.indexOf(route);
+    if (index === this._index) {
+      // Already has this active route.
+      return this;
+    }
+    invariant(index === -1, 'route already exists in the stack');
+    const routeNodes = this._routeNodes.slice(0, this._index);
+    routeNodes.push(new RouteNode(route));
+    return this._update(routeNodes.length - 1, routeNodes);
+  }
+
+  resetRoutes(routes: Array<any>): RouteStack {
+    const index = routes.length - 1;
+    return new RouteStack(index, routes);
+  }
+
   // Iterations
   forEach(callback: IterationCallback, context: ?Object): void {
     this._routeNodes.forEach((node, index) => {

Libraries/CustomComponents/NavigationExperimental/__tests__/NavigationLegacyNavigatorRouteStack-test.js

@@ -1,5 +1,10 @@
 /**
- * Copyright (c) 2015, Facebook, Inc.  All rights reserved.
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
  *
  * Facebook, Inc. ("Facebook") owns all right, title and interest, including
  * all intellectual property and other proprietary rights, in and to the React
@@ -24,9 +29,7 @@
  */
 'use strict';
 
-jest
- .autoMockOff()
- .mock('ErrorUtils');
+jest.dontMock('NavigationLegacyNavigatorRouteStack');
 
 const NavigationLegacyNavigatorRouteStack = require('NavigationLegacyNavigatorRouteStack');
 
@@ -263,11 +266,20 @@ describe('NavigationLegacyNavigatorRouteStack:', () => {
     expect(stack2.index).toBe(0);
   });
 
-  it('throws when popping to empty stack', () => {
-    expect(() => {
-      const stack = new NavigationLegacyNavigatorRouteStack(0, ['a']);
-      stack.pop();
-    }).toThrow();
+  it('does nothing while popping to empty', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(0, ['a']);
+    expect(stack.pop()).toBe(stack);
+    expect(stack.pop().pop()).toBe(stack);
+  });
+
+  it('pops to route', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(1, ['a', 'b', 'c']);
+    expect(stack.popToRoute('b').toArray()).toEqual(['a', 'b']);
+    expect(stack.popToRoute('b').index).toBe(1);
+    expect(stack.popToRoute('a').toArray()).toEqual(['a']);
+    expect(stack.popToRoute('a').index).toBe(0);
+
+    expect(() => {stack.popToRoute('x');}).toThrow();
   });
 
   // Jump
@@ -291,6 +303,24 @@ describe('NavigationLegacyNavigatorRouteStack:', () => {
     }).toThrow();
   });
 
+  it('jumps to route', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(0, ['a', 'b']);
+    expect(stack.jumpTo('b').index).toBe(1);
+  });
+
+  it('jumps backward', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(1, ['a', 'b']);
+    expect(stack.jumpBack().index).toBe(0);
+    expect(stack.jumpBack().jumpBack().jumpBack().index).toBe(0);
+  });
+
+  it('jumps forward', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(0, ['a', 'b']);
+    expect(stack.jumpForward().index).toBe(1);
+    expect(stack.jumpForward().jumpForward().jumpForward().index).toBe(1);
+  });
+
+
   // Replace
   it('replaces route at index', () => {
     const stack1 = new NavigationLegacyNavigatorRouteStack(1, ['a', 'b']);
@@ -317,11 +347,40 @@ describe('NavigationLegacyNavigatorRouteStack:', () => {
     }).toThrow();
   });
 
-  it('throws when replacing at index out of bound', () => {
-    expect(() => {
-      const stack = new NavigationLegacyNavigatorRouteStack(1, ['a', 'b']);
-      stack.replaceAtIndex(100, 'x');
-    }).toThrow();
+  it('does nothing when replacing at index out of bound', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(1, ['a', 'b']);
+    expect(stack.replaceAtIndex(100, 'x')).toBe(stack);
+    expect(stack.replaceAtIndex(-100, 'x')).toBe(stack);
+  });
+
+  it('replaces previous and pop route', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(1, ['a', 'b', 'c']);
+    expect(stack.replacePreviousAndPop('x').toArray()).toEqual(['x']);
+    expect(stack.replacePreviousAndPop('x').index).toBe(0);
+  });
+
+  it('does nothing when there is nothing to replace', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(0, ['a', 'b', 'c']);
+    expect(stack.replacePreviousAndPop('x')).toBe(stack);
+  });
+
+  // Reset
+
+  it('resets route', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(1, ['a', 'b', 'c']);
+    expect(stack.resetTo('b')).toBe(stack);
+
+    expect(stack.resetTo('x').toArray()).toEqual(['a', 'x']);
+    expect(stack.resetTo('x').index).toBe(1);
+
+    expect(() => {stack.resetTo(null);}).toThrow();
+    expect(() => {stack.resetTo('a');}).toThrow();
+  });
+
+  it('resets routes', () => {
+    const stack = new NavigationLegacyNavigatorRouteStack(0, ['a']);
+    expect(stack.resetRoutes(['x', 'y']).toArray()).toEqual(['x', 'y']);
+    expect(stack.resetRoutes(['x', 'y']).index).toBe(1);
   });
 
   // Iteration