Merge branch 'master' into translate-codesplit

Author: masbagal

content/blog/2019-02-23-is-react-translated-yet.md

@@ -43,7 +43,7 @@ We started of with an initial trial period of three languages: Spanish, Japanese
 
 After the trial period, we were ready to accept more languages. I created [a script](https://github.com/reactjs/reactjs.org-translation/blob/master/scripts/create.js) to automate the creation of the new language repo, and a site, [Is React Translated Yet?](https://isreacttranslatedyet.com), to track progress on the different translations. We started *10* new translations on our first day alone!
 
-Because of the automation, the rest of the maintance went mostly smoothly. We eventually created a [Slack channel](https://rt-slack-invite.herokuapp.com) to make it easier for translators to share information, and I released a guide solidifying the [responsibilities of maintainers](https://github.com/reactjs/reactjs.org-translation/blob/master/maintainer-guide.md). Allowing translators to talk with each other was a great boon -- for example, the Arabic, Persian, and Hebrew translations were able to talk to each other in order to get [right-to-left text](https://en.wikipedia.org/wiki/Right-to-left) working!
+Because of the automation, the rest of the maintenance went mostly smoothly. We eventually created a [Slack channel](https://rt-slack-invite.herokuapp.com) to make it easier for translators to share information, and I released a guide solidifying the [responsibilities of maintainers](https://github.com/reactjs/reactjs.org-translation/blob/master/maintainer-guide.md). Allowing translators to talk with each other was a great boon -- for example, the Arabic, Persian, and Hebrew translations were able to talk to each other in order to get [right-to-left text](https://en.wikipedia.org/wiki/Right-to-left) working!
 
 ## The Bot {#the-bot}
 

content/docs/add-react-to-a-website.md

@@ -110,7 +110,7 @@ Commonly, you might want to display React components in multiple places on the H
 
 ### Tip: Minify JavaScript for Production {#tip-minify-javascript-for-production}
 
-Before deploying your website to production, be mindful that unminifed JavaScript can significantly slow down the page for your users.
+Before deploying your website to production, be mindful that unminified JavaScript can significantly slow down the page for your users.
 
 If you already minify the application scripts, **your site will be production-ready** if you ensure that the deployed HTML loads the versions of React ending in `production.min.js`:
 

content/docs/addons-test-utils.md

@@ -53,7 +53,7 @@ Untuk menyiapkan komponen sebelum penegasan, bungkus kode yang me-*render* kompo
 Sebagai contoh, katakanlah kita punya `Counter` komponen:
 
 ```js
-class App extends React.Component {
+class Counter extends React.Component {
   constructor(props) {
     super(props);
     this.state = {count: 0};

content/docs/hooks-custom.md

@@ -18,11 +18,11 @@ import React, { useState, useEffect } from 'react';
 function FriendStatus(props) {
   const [isOnline, setIsOnline] = useState(null);
 
-  function handleStatusChange(status) {
-    setIsOnline(status.isOnline);
-  }
-
   useEffect(() => {
+    function handleStatusChange(status) {
+      setIsOnline(status.isOnline);
+    }
+
     ChatAPI.subscribeToFriendStatus(props.friend.id, handleStatusChange);
     return () => {
       ChatAPI.unsubscribeFromFriendStatus(props.friend.id, handleStatusChange);
@@ -44,11 +44,11 @@ import React, { useState, useEffect } from 'react';
 function FriendListItem(props) {
   const [isOnline, setIsOnline] = useState(null);
 
-  function handleStatusChange(status) {
-    setIsOnline(status.isOnline);
-  }
-
   useEffect(() => {
+    function handleStatusChange(status) {
+      setIsOnline(status.isOnline);
+    }
+
     ChatAPI.subscribeToFriendStatus(props.friend.id, handleStatusChange);
     return () => {
       ChatAPI.unsubscribeFromFriendStatus(props.friend.id, handleStatusChange);
@@ -79,11 +79,11 @@ import React, { useState, useEffect } from 'react';
 function useFriendStatus(friendID) {
   const [isOnline, setIsOnline] = useState(null);
 
-  function handleStatusChange(status) {
-    setIsOnline(status.isOnline);
-  }
-
   useEffect(() => {
+    function handleStatusChange(status) {
+      setIsOnline(status.isOnline);
+    }
+
     ChatAPI.subscribeToFriendStatus(friendID, handleStatusChange);
     return () => {
       ChatAPI.unsubscribeFromFriendStatus(friendID, handleStatusChange);

content/docs/hooks-effect.md

@@ -198,17 +198,17 @@ Let's see how we could write this component with Hooks.
 
 You might be thinking that we'd need a separate effect to perform the cleanup. But code for adding and removing a subscription is so tightly related that `useEffect` is designed to keep it together. If your effect returns a function, React will run it when it is time to clean up:
 
-```js{10-16}
+```js{6-16}
 import React, { useState, useEffect } from 'react';
 
 function FriendStatus(props) {
   const [isOnline, setIsOnline] = useState(null);
 
-  function handleStatusChange(status) {
-    setIsOnline(status.isOnline);
-  }
-
   useEffect(() => {
+    function handleStatusChange(status) {
+      setIsOnline(status.isOnline);
+    }
+
     ChatAPI.subscribeToFriendStatus(props.friend.id, handleStatusChange);
     // Specify how to clean up after this effect:
     return function cleanup() {
@@ -237,6 +237,10 @@ We've learned that `useEffect` lets us express different kinds of side effects a
 
 ```js
   useEffect(() => {
+    function handleStatusChange(status) {
+      setIsOnline(status.isOnline);
+    }
+
     ChatAPI.subscribeToFriendStatus(props.friend.id, handleStatusChange);
     return () => {
       ChatAPI.unsubscribeFromFriendStatus(props.friend.id, handleStatusChange);
@@ -316,15 +320,15 @@ function FriendStatusWithCounter(props) {
 
   const [isOnline, setIsOnline] = useState(null);
   useEffect(() => {
+    function handleStatusChange(status) {
+      setIsOnline(status.isOnline);
+    }
+
     ChatAPI.subscribeToFriendStatus(props.friend.id, handleStatusChange);
     return () => {
       ChatAPI.unsubscribeFromFriendStatus(props.friend.id, handleStatusChange);
     };
   });
-
-  function handleStatusChange(status) {
-    setIsOnline(status.isOnline);
-  }
   // ...
 }
 ```
@@ -394,6 +398,7 @@ Now consider the version of this component that uses Hooks:
 function FriendStatus(props) {
   // ...
   useEffect(() => {
+    // ...
     ChatAPI.subscribeToFriendStatus(props.friend.id, handleStatusChange);
     return () => {
       ChatAPI.unsubscribeFromFriendStatus(props.friend.id, handleStatusChange);
@@ -449,8 +454,12 @@ When we render with `count` updated to `6`, React will compare the items in the
 
 This also works for effects that have a cleanup phase:
 
-```js{6}
+```js{10}
 useEffect(() => {
+  function handleStatusChange(status) {
+    setIsOnline(status.isOnline);
+  }
+
   ChatAPI.subscribeToFriendStatus(props.friend.id, handleStatusChange);
   return () => {
     ChatAPI.unsubscribeFromFriendStatus(props.friend.id, handleStatusChange);
@@ -462,9 +471,13 @@ In the future, the second argument might get added automatically by a build-time
 
 >Note
 >
->If you use this optimization, make sure the array includes **any values from the outer scope that change over time and that are used by the effect**. Otherwise, your code will reference stale values from previous renders. We'll also discuss other optimization options in the [Hooks API reference](/docs/hooks-reference.html).
+>If you use this optimization, make sure the array includes **all values from the component scope (such as props and state) that change over time and that are used by the effect**. Otherwise, your code will reference stale values from previous renders. Learn more about [how to deal with functions](/docs/hooks-faq.html#is-it-safe-to-omit-functions-from-the-list-of-dependencies) and [what to do when the array changes too often](/docs/hooks-faq.html#what-can-i-do-if-my-effect-dependencies-change-too-often).
+>
+>If you want to run an effect and clean it up only once (on mount and unmount), you can pass an empty array (`[]`) as a second argument. This tells React that your effect doesn't depend on *any* values from props or state, so it never needs to re-run. This isn't handled as a special case -- it follows directly from how the inputs array always works.
+>
+>If you pass an empty array (`[]`), the props and state inside the effect will always have their initial values. While passing `[]` as the second argument is closer to the familiar `componentDidMount` and `componentWillUnmount` mental model, there are usually [better](/docs/hooks-faq.html#is-it-safe-to-omit-functions-from-the-list-of-dependencies) [solutions](/docs/hooks-faq.html#what-can-i-do-if-my-effect-dependencies-change-too-often) to avoid re-running effects too often. Also, don't forget that React defers running `useEffect` until after the browser has painted, so doing extra work is less of a problem.
 >
->If you want to run an effect and clean it up only once (on mount and unmount), you can pass an empty array (`[]`) as a second argument. This tells React that your effect doesn't depend on *any* values from props or state, so it never needs to re-run. This isn't handled as a special case -- it follows directly from how the inputs array always works. While passing `[]` is closer to the familiar `componentDidMount` and `componentWillUnmount` mental model, we suggest not making it a habit because it often leads to bugs, [as discussed above](#explanation-why-effects-run-on-each-update). Don't forget that React defers running `useEffect` until after the browser has painted, so doing extra work is less of a problem.
+>We recommend using the [`exhaustive-deps`](https://github.com/facebook/react/issues/14920) rule as part of our [`eslint-plugin-react-hooks`](https://www.npmjs.com/package/eslint-plugin-react-hooks#installation) package. It warns when dependencies are specified incorrectly and suggests a fix.
 
 ## Next Steps {#next-steps}