fix(react): ensure tabs are resilient to optional tabs. (#17862)

react/src/components/__tests__/IonTabs.spec.tsx

@@ -0,0 +1,102 @@
+import React, { ReactElement } from 'react';
+import { Router } from 'react-router-dom';
+import { createMemoryHistory } from 'history'
+import { IonTabs, IonTab, IonTabBar, IonTabButton, IonLabel, IonIcon} from '../index';
+import { render, cleanup } from 'react-testing-library';
+
+afterEach(cleanup)
+
+function renderWithRouter(
+  ui: ReactElement<any>,
+  {
+    route = '/',
+    history = createMemoryHistory({ initialEntries: [route] }),
+  } = {}
+) {
+  return {
+    ...render(<Router history={history}>{ui}</Router>),
+    history
+  }
+}
+
+describe('IonTabs', () => {
+  test('should render happy path', () => {
+    const { container } = renderWithRouter(
+      <IonTabs>
+        <IonTab tab="schedule">Schedule Content</IonTab>
+        <IonTab tab="speakers">Speakers Content</IonTab>
+        <IonTab tab="map">Map Content</IonTab>
+        <IonTab tab="about">About Content</IonTab>
+
+        <IonTabBar slot="bottom">
+          <IonTabButton tab="schedule">
+            <IonLabel>Schedule</IonLabel>
+            <IonIcon name="schedule"></IonIcon>
+          </IonTabButton>
+          <IonTabButton tab="speakers">
+            <IonLabel>Speakers</IonLabel>
+            <IonIcon name="speakers"></IonIcon>
+          </IonTabButton>
+          <IonTabButton tab="map">
+            <IonLabel>Map</IonLabel>
+            <IonIcon name="map"></IonIcon>
+          </IonTabButton>
+          <IonTabButton tab="about">
+            <IonLabel>About</IonLabel>
+            <IonIcon name="about"></IonIcon>
+          </IonTabButton>
+        </IonTabBar>
+      </IonTabs>
+    );
+
+    expect(container.children[0].children.length).toEqual(2);
+    expect(container.children[0].children[0].tagName).toEqual('DIV');
+    expect(container.children[0].children[0].className).toEqual('tabs-inner');
+
+    expect(container.children[0].children[1].tagName).toEqual('ION-TAB-BAR');
+    expect(container.children[0].children[1].children.length).toEqual(4);
+    expect(Array.from(container.children[0].children[1].children).map(c => c.tagName)).toEqual(['ION-TAB-BUTTON', 'ION-TAB-BUTTON', 'ION-TAB-BUTTON', 'ION-TAB-BUTTON']);
+  });
+
+  test('should allow for conditional children', () => {
+    const { container } = renderWithRouter(
+      <IonTabs>
+        {false &&
+          <IonTab tab="schedule">Schedule Content</IonTab>
+        }
+        <IonTab tab="speakers">Speakers Content</IonTab>
+        <IonTab tab="map">Map Content</IonTab>
+        <IonTab tab="about">About Content</IonTab>
+
+        <IonTabBar slot="bottom">
+          {false &&
+          <IonTabButton tab="schedule">
+            <IonLabel>Schedule</IonLabel>
+            <IonIcon name="schedule"></IonIcon>
+          </IonTabButton>
+          }
+          <IonTabButton tab="speakers">
+            <IonLabel>Speakers</IonLabel>
+            <IonIcon name="speakers"></IonIcon>
+          </IonTabButton>
+          <IonTabButton tab="map">
+            <IonLabel>Map</IonLabel>
+            <IonIcon name="map"></IonIcon>
+          </IonTabButton>
+          <IonTabButton tab="about">
+            <IonLabel>About</IonLabel>
+            <IonIcon name="about"></IonIcon>
+          </IonTabButton>
+        </IonTabBar>
+      </IonTabs>
+    );
+
+    expect(container.children[0].children.length).toEqual(2);
+    expect(container.children[0].children[0].tagName).toEqual('DIV');
+    expect(container.children[0].children[0].className).toEqual('tabs-inner');
+
+    expect(container.children[0].children[1].tagName).toEqual('ION-TAB-BAR');
+    expect(container.children[0].children[1].children.length).toEqual(3);
+    expect(Array.from(container.children[0].children[1].children).map(c => c.tagName)).toEqual(['ION-TAB-BUTTON', 'ION-TAB-BUTTON', 'ION-TAB-BUTTON']);
+  });
+});

react/src/components/__tests__/createComponent.spec.tsx

@@ -1,5 +1,5 @@
 import React from 'react';
-import { Components } from '@ionic/core'
+import { Components } from '@ionic/core';
 import { createReactComponent } from '../createComponent';
 import { render, fireEvent, cleanup } from 'react-testing-library';
 

react/src/components/navigation/IonTabBar.tsx

@@ -25,7 +25,7 @@ class IonTabBar extends Component<Props, State> {
     const tabActiveUrls: { [key: string]: Tab } = {};
 
     React.Children.forEach(this.props.children, (child) => {
-      if (typeof child === 'object' && child.type === IonTabButton) {
+      if (child != null && typeof child === 'object' && child.props && child.type === IonTabButton) {
         tabActiveUrls[child.props.tab] = {
           originalHref: child.props.href,
           currentHref: child.props.href
@@ -72,12 +72,15 @@ class IonTabBar extends Component<Props, State> {
   }
 
   renderChild = (activeTab: string) => (child: React.ReactElement<Components.IonTabButtonAttributes & { onIonTabButtonClick: (e: CustomEvent) => void }>) => {
+    if (child != null && typeof child === 'object' && child.props && child.type === IonTabButton) {
       const href = (child.props.tab === activeTab) ? this.props.location.pathname : (this.state.tabs[child.props.tab].currentHref);
 
       return React.cloneElement(child, {
         href,
         onIonTabButtonClick: this.onTabButtonClick
-    })
+      });
+    }
+    return null;
   }
 
   render() {

react/src/components/navigation/IonTabs.tsx

@@ -32,10 +32,13 @@ export default class IonTabs extends Component<Props> {
     let tabBar: React.ReactElement<{ slot: 'bottom' | 'top' }>;
 
     React.Children.forEach(this.props.children, child => {
-      if (typeof child === 'object' && child.type === IonRouterOutlet) {
+      if (child == null || typeof child !== 'object' || !child.hasOwnProperty('type')) {
+        return;
+      }
+      if (child.type === IonRouterOutlet) {
         outlet = child;
       }
-      if (typeof child === 'object' && child.type === IonTabBar) {
+      if (child.type === IonTabBar) {
         tabBar = child;
       }
     });