From a8098b8c7deedcc3fae59b128452efa4cfe9c96a Mon Sep 17 00:00:00 2001
From: Josep M Sobrepere <josepot@gmail.com>
Date: Thu, 2 May 2019 18:14:44 +0200
Subject: [PATCH] Remove deps of useSelector

---
 src/hooks/useSelector.js       | 14 +++++---------
 test/hooks/useSelector.spec.js | 30 +-----------------------------
 2 files changed, 6 insertions(+), 38 deletions(-)

diff --git a/src/hooks/useSelector.js b/src/hooks/useSelector.js
index 83e1666f9..8e40cfa10 100644
--- a/src/hooks/useSelector.js
+++ b/src/hooks/useSelector.js
@@ -24,8 +24,6 @@ const useIsomorphicLayoutEffect =
  * useful if you provide a selector that memoizes values).
  *
  * @param {Function} selector the selector function
- * @param {any[]} deps (optional) dependencies array to control referential stability
- * of the selector
  *
  * @returns {any} the selected state
  *
@@ -36,11 +34,11 @@ const useIsomorphicLayoutEffect =
  * import { RootState } from './store'
  *
  * export const CounterComponent = () => {
- *   const counter = useSelector(state => state.counter, [])
+ *   const counter = useSelector(state => state.counter)
  *   return <div>{counter}</div>
  * }
  */
-export function useSelector(selector, deps) {
+export function useSelector(selector) {
   invariant(selector, `You must pass a selector to useSelectors`)
 
   const { store, subscription: contextSub } = useReduxContext()
@@ -51,15 +49,13 @@ export function useSelector(selector, deps) {
     contextSub
   ])
 
-  const memoizedSelector = useMemo(() => selector, deps)
-
   const latestSubscriptionCallbackError = useRef()
-  const latestSelector = useRef(memoizedSelector)
+  const latestSelector = useRef(selector)
 
   let selectedState = undefined
 
   try {
-    selectedState = memoizedSelector(store.getState())
+    selectedState = selector(store.getState())
   } catch (err) {
     let errorMessage = `An error occured while selecting the store state: ${
       err.message
@@ -77,7 +73,7 @@ export function useSelector(selector, deps) {
   const latestSelectedState = useRef(selectedState)
 
   useIsomorphicLayoutEffect(() => {
-    latestSelector.current = memoizedSelector
+    latestSelector.current = selector
     latestSelectedState.current = selectedState
     latestSubscriptionCallbackError.current = undefined
   })
diff --git a/test/hooks/useSelector.spec.js b/test/hooks/useSelector.spec.js
index e0fb95c8b..c37c5b6e6 100644
--- a/test/hooks/useSelector.spec.js
+++ b/test/hooks/useSelector.spec.js
@@ -1,6 +1,6 @@
 /*eslint-disable react/prop-types*/
 
-import React, { useReducer } from 'react'
+import React from 'react'
 import { createStore } from 'redux'
 import { renderHook, act } from 'react-hooks-testing-library'
 import * as rtl from 'react-testing-library'
@@ -154,34 +154,6 @@ describe('React', () => {
 
           expect(renderedItems.length).toBe(1)
         })
-
-        it('re-uses the selector if deps do not change', () => {
-          let selectorId = 0
-          let forceRender
-
-          const Comp = () => {
-            const [, f] = useReducer(c => c + 1, 0)
-            forceRender = f
-            const renderedSelectorId = selectorId++
-            const value = useSelector(() => renderedSelectorId, [])
-            renderedItems.push(value)
-            return <div />
-          }
-
-          rtl.render(
-            <ProviderMock store={store}>
-              <Comp />
-            </ProviderMock>
-          )
-
-          rtl.act(forceRender)
-
-          // this line verifies the susbcription callback uses the same memoized selector and therefore
-          // does not cause a re-render
-          store.dispatch({ type: '' })
-
-          expect(renderedItems).toEqual([0, 0])
-        })
       })
 
       describe('edge cases', () => {