refactor: use private keyword for private methods

packages/drawer/example/.eslintrc

@@ -8,7 +8,7 @@
           'react-navigation-drawer',
           'react-native-gesture-handler',
           'react-native-reanimated',
-          'react-native-vector-icons',
+          'react-native-vector-icons/MaterialIcons',
         ],
     },
 }

packages/drawer/src/utils/invariant.tsx

@@ -1,48 +0,0 @@
-/**
- * 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.
- */
-
-'use strict';
-
-/**
- * Use invariant() to assert state which your program assumes to be true.
- *
- * Provide sprintf-style format (only %s is supported) and arguments
- * to provide information about what broke and what you were
- * expecting.
- *
- * The invariant message will be stripped in production, but the invariant
- * will remain to ensure logic does not differ in production.
- */
-
-export default function invariant(
-  condition: any,
-  format: string,
-  ...args: any[]
-) {
-  if (format === undefined) {
-    throw new Error('invariant requires an error message argument');
-  }
-
-  if (!condition) {
-    var error;
-    if (format === undefined) {
-      error = new Error(
-        'Minified exception occurred; use the non-minified dev environment for the full error message and additional helpful warnings.'
-      );
-    } else {
-      var argIndex = 0;
-      error = new Error(format.replace(/%s/g, () => args[argIndex++]));
-      error.name = 'Invariant Violation';
-    }
-
-    // @ts-ignore
-    error.framesToPop = 1; // we don't care about invariant's own frame
-    throw error;
-  }
-}

packages/drawer/src/views/DrawerSidebar.tsx

@@ -3,7 +3,6 @@ import { StyleSheet, View, Animated, ViewStyle } from 'react-native';
 import { NavigationActions } from '@react-navigation/core';
 
 import { Props as DrawerNavigatorItemsProps } from './DrawerNavigatorItems';
-import invariant from '../utils/invariant';
 import { Navigation, Scene, Route } from '../types';
 
 export type ContentComponentProps = DrawerNavigatorItemsProps & {
@@ -28,17 +27,20 @@ type Props = {
  * Component that renders the sidebar screen of the drawer.
  */
 class DrawerSidebar extends React.PureComponent<Props> {
-  _getScreenOptions = (routeKey: string) => {
+  private getScreenOptions = (routeKey: string) => {
     const descriptor = this.props.descriptors[routeKey];
-    invariant(
-      descriptor.options,
-      'Cannot access screen descriptor options from drawer sidebar'
-    );
+
+    if (!descriptor.options) {
+      throw new Error(
+        'Cannot access screen descriptor options from drawer sidebar'
+      );
+    }
+
     return descriptor.options;
   };
 
-  _getLabel = ({ focused, tintColor, route }: Scene) => {
-    const { drawerLabel, title } = this._getScreenOptions(route.key);
+  private getLabel = ({ focused, tintColor, route }: Scene) => {
+    const { drawerLabel, title } = this.getScreenOptions(route.key);
     if (drawerLabel) {
       return typeof drawerLabel === 'function'
         ? drawerLabel({ tintColor, focused })
@@ -52,8 +54,8 @@ class DrawerSidebar extends React.PureComponent<Props> {
     return route.routeName;
   };
 
-  _renderIcon = ({ focused, tintColor, route }: Scene) => {
-    const { drawerIcon } = this._getScreenOptions(route.key);
+  private renderIcon = ({ focused, tintColor, route }: Scene) => {
+    const { drawerIcon } = this.getScreenOptions(route.key);
     if (drawerIcon) {
       return typeof drawerIcon === 'function'
         ? drawerIcon({ tintColor, focused })
@@ -62,7 +64,13 @@ class DrawerSidebar extends React.PureComponent<Props> {
     return null;
   };
 
-  _onItemPress = ({ route, focused }: { route: Route; focused: boolean }) => {
+  private handleItemPress = ({
+    route,
+    focused,
+  }: {
+    route: Route;
+    focused: boolean;
+  }) => {
     if (focused) {
       this.props.navigation.closeDrawer();
     } else {
@@ -81,7 +89,11 @@ class DrawerSidebar extends React.PureComponent<Props> {
 
     const { state } = this.props.navigation;
 
-    invariant(typeof state.index === 'number', 'should be set');
+    if (typeof state.index !== 'number') {
+      throw new Error(
+        'The index of the route should be state in the navigation state'
+      );
+    }
 
     return (
       <View style={[styles.container, this.props.style]}>
@@ -95,9 +107,9 @@ class DrawerSidebar extends React.PureComponent<Props> {
             state.routes[state.index] ? state.routes[state.index].key : null
           }
           screenProps={this.props.screenProps}
-          getLabel={this._getLabel}
-          renderIcon={this._renderIcon}
-          onItemPress={this._onItemPress}
+          getLabel={this.getLabel}
+          renderIcon={this.renderIcon}
+          onItemPress={this.handleItemPress}
           drawerPosition={this.props.drawerPosition}
         />
       </View>