navSelectors [nfc]: Remove now-unused getChatScreenParams and its hel…

…pers.

navSelectors and navActions are kind of relics from before zulip#3804,
and we already have zulip#4417 for removing most or all of navActions.

Help along the removal of navSelectors by removing these things that
we stopped using in a recent commit.

src/nav/__tests__/navSelectors-test.js

@@ -1,67 +1,8 @@
 import deepFreeze from 'deep-freeze';
 
-import {
-  getCurrentRouteName,
-  getCurrentRouteParams,
-  getChatScreenParams,
-  getSameRoutesCount,
-} from '../navSelectors';
+import { getSameRoutesCount } from '../navSelectors';
 import * as NavigationService from '../NavigationService';
 
-describe('getCurrentRouteName', () => {
-  test('return name of the current route', () => {
-    NavigationService.getState = jest.fn().mockReturnValue(
-      deepFreeze({
-        index: 1,
-        routes: [
-          { name: 'first', params: { email: 'a@a.com' } },
-          { name: 'second', params: { email: 'b@a.com' } },
-        ],
-      }),
-    );
-
-    const expectedResult = 'second';
-
-    const actualResult = getCurrentRouteName();
-
-    expect(actualResult).toEqual(expectedResult);
-  });
-});
-
-describe('getCurrentRouteParams', () => {
-  test('return params of the current route', () => {
-    NavigationService.getState = jest.fn().mockReturnValue(
-      deepFreeze({
-        index: 1,
-        routes: [
-          { name: 'first', params: { email: 'a@a.com' } },
-          { name: 'second', params: { email: 'b@a.com' } },
-        ],
-      }),
-    );
-    const expectedResult = { email: 'b@a.com' };
-
-    const actualResult = getCurrentRouteParams();
-
-    expect(actualResult).toEqual(expectedResult);
-  });
-});
-
-describe('getChatScreenParams', () => {
-  test('when no params are passed do not return "undefined"', () => {
-    NavigationService.getState = jest.fn().mockReturnValue(
-      deepFreeze({
-        index: 0,
-        routes: [{ name: 'chat' }],
-      }),
-    );
-
-    const actualResult = getChatScreenParams();
-
-    expect(actualResult).toBeDefined();
-  });
-});
-
 describe('getSameRoutesCount', () => {
   test('if no routes the count of same routes is 0', () => {
     NavigationService.getState = jest.fn().mockReturnValue(

src/nav/navSelectors.js

@@ -1,23 +1,12 @@
 /* @flow strict-local */
-import type { NavigationState, Route, ScreenParams } from '@react-navigation/native';
+import type { NavigationState, Route } from '@react-navigation/native';
 
 import * as NavigationService from './NavigationService';
 
 export const getNavState = (): NavigationState => NavigationService.getState();
 
 export const getNavigationRoutes = (): $ReadOnlyArray<Route<string>> => getNavState().routes;
 
-const getNavigationIndex = () => getNavState().index;
-
-const getCurrentRoute = (): void | Route<string> => getNavigationRoutes()[getNavigationIndex()];
-
-export const getCurrentRouteName = (): void | string => getCurrentRoute()?.name;
-
-export const getCurrentRouteParams = (): void | ScreenParams => getCurrentRoute()?.params;
-
-export const getChatScreenParams = (): ScreenParams | {| narrow: void |} =>
-  getCurrentRouteParams() ?? { narrow: undefined };
-
 export const getSameRoutesCount = (): number => {
   const routes = getNavigationRoutes();
   let i = routes.length - 1;