Merge pull request #322 from reactjs/sync-7e4f503d

Sync with reactjs.org @ 7e4f503

Author: koba04

.circleci/config.yml

@@ -2,12 +2,12 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/node:8
+      - image: circleci/node:12
     steps:
       - checkout
       - restore_cache:
           keys:
-          - dependencies-{{ checksum "yarn.lock" }}
+            - dependencies-{{ checksum "yarn.lock" }}
       - run:
           name: Install
           command: yarn install --pure-lockfile

.nvmrc

@@ -1 +1 @@
-lts/carbon
+lts/erbium

README.md

@@ -9,7 +9,7 @@ This repo contains the source code and documentation powering [ja.reactjs.org](h
 ### Prerequisites
 
 1. Git
-1. Node: any 8.x version starting with 8.4.0 or greater
+1. Node: any 12.x version starting with v12.0.0 or greater
 1. Yarn: See [Yarn website for installation instructions](https://yarnpkg.com/lang/en/docs/install/)
 1. A fork of the repo (for any contributions)
 1. A clone of the [ja.reactjs.org repo](https://github.com/reactjs/ja.reactjs.org) on your local machine

content/blog/2013-06-19-community-roundup-2.md

@@ -9,7 +9,7 @@ Since the launch we have received a lot of feedback and are actively working on
 
 [Andrew Greig](http://www.andrewgreig.com/) made a blog post that gives a high level description of what React is.
 
-> I have been using Facebooks recently released JavaScript framework called React.js for the last few days and have managed to obtain a rather high level understanding of how it works and formed a good perspective on how it fits in to the entire javascript framework ecosystem.
+> I have been using Facebook's recently released JavaScript framework called React.js for the last few days and have managed to obtain a rather high level understanding of how it works and formed a good perspective on how it fits in to the entire javascript framework ecosystem.
 >
 > Basically, React is not an MVC framework. It is not a replacement for Backbone or Knockout or Angular, instead it is designed to work with existing frameworks and help extend their functionality.
 >

content/blog/2015-03-26-introducing-react-native.md

@@ -13,4 +13,4 @@ For more details, see [Tom Occhino's post on the Facebook Engineering blog](http
 >
 > *It's worth noting that we're not chasing “write once, run anywhere.” Different platforms have different looks, feels, and capabilities, and as such, we should still be developing discrete apps for each platform, but the same set of engineers should be able to build applications for whatever platform they choose, without needing to learn a fundamentally different set of technologies for each. We call this approach “learn once, write anywhere.”*
 
-To learn more, visit the [React Native website](https://facebook.github.io/react-native/).
+To learn more, visit the [React Native website](https://reactnative.dev/).

content/blog/2015-05-01-graphql-introduction.md

@@ -3,7 +3,7 @@ title: "GraphQL Introduction"
 author: [schrockn]
 ---
 
-At the React.js conference in late January 2015, we revealed our next major technology in the React family: [Relay](http://facebook.github.io/react/blog/2015/02/20/introducing-relay-and-graphql.html). 
+At the React.js conference in late January 2015, we revealed our next major technology in the React family: [Relay](/blog/2015/02/20/introducing-relay-and-graphql.html). 
 
 Relay is a new way of structuring client applications that co-locates data-fetching requirements and React components. Instead of placing data fetching logic in some other part of the client application – or embedding this logic in a custom endpoint on the server – we instead co-locate a *declarative* data-fetching specification alongside the React component. The language of this declarative specification is GraphQL.
 

content/blog/2018-06-07-you-probably-dont-need-derived-state.md

@@ -40,7 +40,7 @@ Problems arise when any of these constraints are changed. This typically comes i
 
 A common misconception is that `getDerivedStateFromProps` and `componentWillReceiveProps` are only called when props "change". These lifecycles are called any time a parent component rerenders, regardless of whether the props are "different" from before. Because of this, it has always been unsafe to _unconditionally_ override state using either of these lifecycles. **Doing so will cause state updates to be lost.**
 
-Let’s consider an example to demonstrate the problem. Here is a `EmailInput` component that "mirrors" an email prop in state:
+Let’s consider an example to demonstrate the problem. Here is an `EmailInput` component that "mirrors" an email prop in state:
 ```js
 class EmailInput extends Component {
   state = { email: this.props.email };

content/blog/2018-11-13-react-conf-recap.md

@@ -21,6 +21,6 @@ On the morning of Day 2, Andrew Clark and Brian Vaughn presented Concurrent Rend
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/UcqRXTriUVI" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
-In the afternoon, Parashuram N spoke in detail about React Native’s New Architecture, a long-term project that the React Native team has been working on over the past year and [announced in June](https://facebook.github.io/react-native/blog/2018/06/14/state-of-react-native-2018). We’re really excited about the potential of this project to improve performance, simplify interoperability with other libraries, and set a strong foundation for the future of React Native.
+In the afternoon, Parashuram N spoke in detail about React Native’s New Architecture, a long-term project that the React Native team has been working on over the past year and [announced in June](https://reactnative.dev/blog/2018/06/14/state-of-react-native-2018). We’re really excited about the potential of this project to improve performance, simplify interoperability with other libraries, and set a strong foundation for the future of React Native.
 
 Now that the conference is over, all 28 conference talks are [available to stream online](https://www.youtube.com/playlist?list=PLPxbbTqCLbGE5AihOSExAa4wUM-P42EIJ). There are tons of great ones from both days. We can’t wait until next year!

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

@@ -55,7 +55,7 @@ Creating the [sync script](https://github.com/reactjs/reactjs.org-translation/bl
 
 The problem was finding a place for the bot to run. I'm a frontend developer for a reason -- Heroku and its ilk are alien to me and *endlessly* frustrating. In fact, until this past Tuesday, I was running the script by hand on my local machine!
 
-The biggest challenge was space. Each fork of the repo is around 100MB -- which takes minutes to clone on my local machine. We have *32* forks, and the free tiers or most deployment platforms I checked limited you to 512MB of storage. 
+The biggest challenge was space. Each fork of the repo is around 100MB -- which takes minutes to clone on my local machine. We have *32* forks, and the free tiers of most deployment platforms I checked limited you to 512MB of storage. 
 
 After lots of notepad calculations, I found a solution: delete each repo once we've finished the script and limit the concurrency of `sync` scripts that run at once to be within the storage requirements. Luckily, Heroku dynos have a much faster Internet connection and are able to clone even the React repo quickly.
 

content/blog/2019-08-08-react-v16.9.0.md

@@ -149,7 +149,7 @@ These estimates were too optimistic, and we've needed to adjust them.
 
 **tldr:** We shipped Hooks on time, but we're regrouping Concurrent Mode and Suspense for Data Fetching into a single release that we intend to release later this year.
 
-In February, we [shipped a stable 16.8 release](/blog/2019/02/06/react-v16.8.0.html) including React Hooks, with React Native support coming [a month later](https://facebook.github.io/react-native/blog/2019/03/12/releasing-react-native-059). However, we underestimated the follow-up work for this release, including the lint rules, developer tools, examples, and more documentation. This shifted the timeline by a few months.
+In February, we [shipped a stable 16.8 release](/blog/2019/02/06/react-v16.8.0.html) including React Hooks, with React Native support coming [a month later](https://reactnative.dev/blog/2019/03/12/releasing-react-native-059). However, we underestimated the follow-up work for this release, including the lint rules, developer tools, examples, and more documentation. This shifted the timeline by a few months.
 
 Now that React Hooks are rolled out, the work on Concurrent Mode and Suspense for Data Fetching is in full swing. The [new Facebook website that's currently in active development](https://twitter.com/facebook/status/1123322299418124289) is built on top of these features. Testing them with real code helped discover and address many issues before they can affect the open source users. Some of these fixes involved an internal redesign of these features, which has also caused the timeline to slip.
 

content/blog/2020-02-26-react-v16.13.0.md

@@ -21,7 +21,7 @@ Warning: Cannot update a component from inside the function body of a different
 
 **This warning will help you find application bugs caused by unintentional state changes.** In the rare case that you intentionally want to change the state of another component as a result of rendering, you can wrap the `setState` call into `useEffect`.
 
-### Warnings for conflicting style rules
+### Warnings for conflicting style rules {#warnings-for-conflicting-style-rules}
 
 When dynamically applying a `style` that contains longhand and shorthand versions of CSS properties, particular combinations of updates can cause inconsistent styling. For example: 
 

content/community/conferences.md

@@ -12,11 +12,6 @@ Do you know of a local React.js conference? Add it here! (Please keep the list c
 
 ## Upcoming Conferences {#upcoming-conferences}
 
-### ReactConf Japan 2020 {#reactconfjp-2020}
-March 21, 2020 in Tokyo, Japan
-
-[Website](https://reactconf.jp/) - [Twitter](https://twitter.com/reactjp)
-
 ### Reactathon 2020 {#reactathon-2020}
 March 30 - 31, 2020 in San Francisco, CA
 
@@ -42,11 +37,6 @@ May 1, 2020. Streamed online on YouTube.
 
 [Website](https://www.bytesized.xyz) - [Twitter](https://twitter.com/bytesizedcode) - [YouTube](https://www.youtube.com/channel/UC046lFvJZhiwSRWsoH8SFjg)
 
-### render(ATL) 2020 {#render-atlanta-2020}
-May 4-6, 2020. Atlanta, GA, USA.
-
-[Website](https://renderatl.com) - [Twitter](https://twitter.com/renderATL) - [Instagram](https://www.instagram.com/renderatl/) - [Facebook](https://www.facebook.com/renderatl/)
-
 ### ReactEurope 2020 {#reacteurope-2020}
 May 14-15, 2020 in Paris, France
 
@@ -82,6 +72,11 @@ July 29-30, 2020. Portland, Oregon, USA.
 
 [Website](https://infinite.red/ChainReactConf) - [Twitter](https://twitter.com/ChainReactConf)
 
+### render(ATL) 2020 {#render-atlanta-2020} 
+August 24-26, 2020. Atlanta, GA, USA.
+
+[Website](https://renderatl.com) - [Twitter](https://twitter.com/renderATL) - [Instagram](https://www.instagram.com/renderatl/) - [Facebook](https://www.facebook.com/renderatl/) - [LinkedIn](https://www.linkedin.com/company/renderatl)
+
 ### ComponentsConf 2020 {#components20}
 September 1, 2020 in Melbourne, Australia
 

content/docs/codebase-overview.md

@@ -15,12 +15,6 @@ redirect_from:
 
 これらの規約のいずれかをあなたの React アプリケーションで推奨しているというわけでは必ずしもありません。規約の多くは歴史的な理由で存在しており、時間とともに変化する可能性があります。
 
-### 外部の依存関係 {#external-dependencies}
-
-React はほとんど外部の依存関係を持っていません。通常、`require()` は React 自身のコードベースのファイルを指します。ただし、比較的にまれな例外がいくつかあります。
-
-[fbjs リポジトリ](https://github.com/facebook/fbjs)は React がいくつかの小さなユーティリティを [Relay](https://github.com/facebook/relay) のようなライブラリと共有し、それらと同期を保つために存在しています。Facebook のエンジニアが必要に応じて変更を行えるようであってほしいので、Node のエコシステムにある同等の小さなモジュール群には依存しません。fbjs 内にあるユーティリティは全て非公開 API であり、それらは React のような Facebook プロジェクトでのみ使用されるためのものです。
-
 ### 最上位フォルダ {#top-level-folders}
 
 [React リポジトリ](https://github.com/facebook/react)をクローンした後、プロジェクトのルートディレクトリに複数のフォルダがあることに気がつくでしょう：
@@ -171,7 +165,7 @@ React core のコードはソースツリーの [`packages/react`](https://githu
 
 ### レンダラ {#renderers}
 
-React は元々 DOM のために作成されましたが、後になって [React Native](http://facebook.github.io/react-native/) によりネイティブなプラットフォームもサポートするようになりました。これにより React の内部に "レンダラ (renderer)" の概念が導入されました。
+React は元々 DOM のために作成されましたが、後になって [React Native](https://reactnative.dev/) によりネイティブなプラットフォームもサポートするようになりました。これにより React の内部に "レンダラ (renderer)" の概念が導入されました。
 
 **レンダラは React ツリーを、基盤となるプラットフォーム固有の呼び出しへと変換する方法を管理します。**
 

content/docs/conditional-rendering.md

@@ -176,11 +176,10 @@ render() {
   const isLoggedIn = this.state.isLoggedIn;
   return (
     <div>
-      {isLoggedIn ? (
-        <LogoutButton onClick={this.handleLogoutClick} />
-      ) : (
-        <LoginButton onClick={this.handleLoginClick} />
-      )}
+      {isLoggedIn
+        ? <LogoutButton onClick={this.handleLogoutClick} />
+        : <LoginButton onClick={this.handleLoginClick} />
+      }
     </div>
   );
 }

content/docs/design-principles.md

@@ -126,7 +126,7 @@ UI は動的ですが、props と state の同期的な `render()` 関数によ
 
 ### DOM を超えて {#beyond-the-dom}
 
-私たちは React の価値を、バグの少ないコンポーネントを書いてうまく構成することができるという点に見ています。DOM は React のオリジナルのレンダーターゲットですが、[React Native](https://facebook.github.io/react-native/) は Facebook とコミュニティの両方において同じくらい重要です。
+私たちは React の価値を、バグの少ないコンポーネントを書いてうまく構成することができるという点に見ています。DOM は React のオリジナルのレンダーターゲットですが、[React Native](https://reactnative.dev/) は Facebook とコミュニティの両方において同じくらい重要です。
 
 レンダラーに依存しないことは React の重要な設計上の制約です。それは内部表現にいくらかのオーバーヘッドを追加します。その一方で、コアへの改善はすべてのプラットフォームに行きわたります。
 

content/docs/handling-events.md

@@ -130,7 +130,7 @@ class LoggingButton extends React.Component {
   render() {
     // This syntax ensures `this` is bound within handleClick
     return (
-      <button onClick={(e) => this.handleClick(e)}>
+      <button onClick={() => this.handleClick()}>
         Click me
       </button>
     );

content/docs/hooks-faq.md

@@ -71,7 +71,7 @@ React バージョン 16.8.0 より、以下においてフックの安定版の
 
 **フックを利用するには、すべての React のパッケージが 16.8.0 以上である必要があります**。例えば React DOM の更新を忘れた場合、フックは動作しません。
 
-React Native は[バージョン 0.59](https://facebook.github.io/react-native/blog/2019/03/12/releasing-react-native-059) 以降でフックをサポートします。
+React Native は[バージョン 0.59](https://reactnative.dev/blog/2019/03/12/releasing-react-native-059) 以降でフックをサポートします。
 
 ### クラスコンポーネントを全部書き換える必要があるのですか？ {#do-i-need-to-rewrite-all-my-class-components}
 
@@ -588,7 +588,7 @@ function ProductPage({ productId }) {
   const [product, setProduct] = useState(null);
 
   async function fetchProduct() {
-    const response = await fetch('http://myapi/product' + productId); // Uses productId prop
+    const response = await fetch('http://myapi/product/' + productId); // Uses productId prop
     const json = await response.json();
     setProduct(json);
   }
@@ -609,7 +609,7 @@ function ProductPage({ productId }) {
   useEffect(() => {
     // By moving this function inside the effect, we can clearly see the values it uses.
     async function fetchProduct() {
-      const response = await fetch('http://myapi/product' + productId);
+      const response = await fetch('http://myapi/product/' + productId);
       const json = await response.json();
       setProduct(json);
     }

content/docs/hooks-intro.md

@@ -31,7 +31,7 @@ function Example() {
 
 > 補足
 >
-> React 16.8.0 がフックをサポートする最初のバージョンです。アップグレードの際は、React DOM を含むすべてのパッケージの更新を忘れないようにしてください。React Native は [React Native 0.59 リリース](https://facebook.github.io/react-native/blog/2019/03/12/releasing-react-native-059)以降でフックをサポートします。
+> React 16.8.0 がフックをサポートする最初のバージョンです。アップグレードの際は、React DOM を含むすべてのパッケージの更新を忘れないようにしてください。React Native は [React Native 0.59 リリース](https://reactnative.dev/blog/2019/03/12/releasing-react-native-059)以降でフックをサポートします。
 
 ## ビデオによる紹介 {#video-introduction}
 

content/docs/hooks-rules.md

@@ -27,6 +27,8 @@ prev: hooks-effect.html
 
 これらの 2 つのルールを強制できる [`eslint-plugin-react-hooks`](https://www.npmjs.com/package/eslint-plugin-react-hooks) という ESLint のプラグインをリリースしました。試したい場合はあなたのプロジェクトに以下のようにして加えることができます。
 
+このプラグインは [Create React App](/docs/create-a-new-react-app.html#create-react-app) ではデフォルトで含まれています。
+
 ```bash
 npm install eslint-plugin-react-hooks --save-dev
 ```
@@ -46,8 +48,6 @@ npm install eslint-plugin-react-hooks --save-dev
 }
 ```
 
-このプラグインは [Create React App](/docs/create-a-new-react-app.html#create-react-app) ではデフォルトで含まれています。
-
 **次のページまで飛ばして[独自のフック](/docs/hooks-custom.html)を書く方法について学んでも構いません。**このページの続きの部分ではこれらのルールの背後にある根拠について述べていきます。
 
 ## 解説 {#explanation}