Merge pull request #36 from reactjs/sync-821e2072

balazsorban44 · web-flow · commit dbdc65958243 · 2020-02-27T09:33:24.000+01:00
Sync with reactjs.org @ 821e207
diff --git a/content/community/conferences.md b/content/community/conferences.md
@@ -22,6 +22,11 @@ February 27 & 28, 2020 in Sydney, Australia
 
 [Website](https://reactconfau.com/) - [Twitter](https://twitter.com/reactconfau) - [Facebook](https://www.facebook.com/reactconfau) - [Instagram](https://www.instagram.com/reactconfau/)
 
+### 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
 
@@ -40,7 +45,12 @@ April 23 - 24, 2020 in Kraków, Poland
 ### React Day Bangalore 2020 {#react-day-bangalore-2020}
 April 25, 2020 in Bangalore, India
 
-[Website](https://reactday.in) - [Twitter](https://twitter.com/ReactDayIn)
+[Website](https://reactday.in) - [Twitter](https://twitter.com/ReactDayIn) - [LinkedIn](https://www.linkedin.com/company/react-day/)
+
+### Byteconf React 2020 {#byteconf-react-2020}
+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.
@@ -72,11 +82,26 @@ July 17, 2020. New York City, USA.
 
 [Website](https://reactweek.nyc/) - [Twitter](https://twitter.com/reactweek) - [Facebook](https://www.facebook.com/reactweek)
 
+### React La Conferencia 2020 {#react-la-conferencia-2020}
+July 18, 2020. Medellín, Colombia.
+
+[Website](https://reactlaconf.co/) - [Twitter](https://twitter.com/reactlaconf)
+
+### Chain React 2020 {#chain-react-2020}
+July 29-30, 2020. Portland, Oregon, USA.
+
+[Website](https://infinite.red/ChainReactConf) - [Twitter](https://twitter.com/ChainReactConf)
+
 ### ComponentsConf 2020 {#components20}
 September 1, 2020 in Melbourne, Australia
 
 [Website](https://www.componentsconf.com.au/) - [Twitter](https://twitter.com/ComponentsConf) - [Facebook](https://www.facebook.com/ComponentsConf/) - [LinkedIn](https://www.linkedin.com/company/componentsconf/) - [YouTube](https://www.youtube.com/ComponentsConf)
 
+### React Native EU 2020 {#react-native-eu-2020}
+September 5-6, 2020 in Wrocław, Poland
+
+[Website](https://www.react-native.eu/) - [Twitter](https://twitter.com/react_native_eu) - [Facebook](https://www.facebook.com/reactnativeeu/) - [YouTube](https://www.youtube.com/watch?v=m0GfmlGFh3E&list=PLZ3MwD-soTTHy9_88QPLF8DEJkvoB5Tl-) - [Instagram](https://www.instagram.com/reactnative_eu/)
+
 ### React India 2020 {#react-india-2020}
 November 6, 2020 in Mumbai, India
 
diff --git a/content/community/examples.md b/content/community/examples.md
@@ -12,7 +12,6 @@ There are many example projects created by the React community. Feel free to add
 * **[Zeldog](https://yannsainty.github.io/Zeldog/)** A Zelda like game with a dog fighting ducks and more to eat pizza !
 * **[Calculator](https://github.com/ahfarmer/calculator)** Implementation of the iOS calculator built in React
 * **[Emoji Search](https://github.com/ahfarmer/emoji-search)** Simple React app for searching emoji
-* **[GitHub Battle App](https://tm.dev/react-course-project/)** Battle two GitHub users and see the most popular Github projects for any language.
 * **[React Powered Hacker News Client](https://github.com/insin/react-hn)** A React & `react-router`-powered implementation of Hacker News using its Firebase API
 * **[Pokedex](https://github.com/alik0211/pokedex)** The list of Pokémon with live search
 * **[Shopping Cart](https://github.com/jeffersonRibeiro/react-shopping-cart)** Simple e-commerce cart application built using React
diff --git a/content/community/external-resources.md b/content/community/external-resources.md
@@ -18,4 +18,4 @@ There are many wonderful curated resources the React community has put together.
 
 - [Awesome React Talks](https://github.com/tiaanduplessis/awesome-react-talks) - A curated list of React talks.
 
-- [Hero35 React Hub](https://hero35.com/stack/react) - A website with _all_ React conferences and talks, categorized & curated.
+- [Hero35 React Hub](https://hero35.com/topic/react) - A website with _all_ React conferences and talks, categorized & curated.
diff --git a/content/community/meetups.md b/content/community/meetups.md
@@ -95,6 +95,7 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Tel Aviv](https://www.meetup.com/ReactJS-Israel/)
 
 ## Malaysia {#malaysia}
+* [Kuala Lumpur](https://www.kl-react.com/)
 * [Penang](https://www.facebook.com/groups/reactpenang/)
 
 ## Netherlands {#netherlands}
@@ -111,6 +112,9 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Karachi](https://www.facebook.com/groups/902678696597634/)
 * [Lahore](https://www.facebook.com/groups/ReactjsLahore/)
 
+## Panama {#panama}
+* [Panama](https://www.meetup.com/React-Panama/)
+
 ## Peru {#peru}
 * [Lima](https://www.meetup.com/ReactJS-Peru/)
 
@@ -144,13 +148,15 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Kyiv](https://www.meetup.com/Kyiv-ReactJS-Meetup)
 
 ## US {#us}
+* [Ann Arbor, MI - ReactJS](https://www.meetup.com/AnnArbor-jsx/)
 * [Atlanta, GA - ReactJS](https://www.meetup.com/React-ATL/)
 * [Austin, TX - ReactJS](https://www.meetup.com/ReactJS-Austin-Meetup/)
 * [Boston, MA - ReactJS](https://www.meetup.com/ReactJS-Boston/)
 * [Boston, MA - React Native](https://www.meetup.com/Boston-React-Native-Meetup/)
 * [Charlotte, NC - ReactJS](https://www.meetup.com/ReactJS-Charlotte/)
 * [Charlotte, NC - React Native](https://www.meetup.com/cltreactnative/)
 * [Chicago, IL - ReactJS](https://www.meetup.com/React-Chicago/)
+* [Cleveland, OH - ReactJS](https://www.meetup.com/Cleveland-React/)
 * [Columbus, OH - ReactJS](https://www.meetup.com/ReactJS-Columbus-meetup/)
 * [Dallas, TX - ReactJS](https://www.meetup.com/ReactDallas/)
 * [Detroit, MI - Detroit React User Group](https://www.meetup.com/Detroit-React-User-Group/)
diff --git a/content/docs/concurrent-mode-adoption.md b/content/docs/concurrent-mode-adoption.md
@@ -80,7 +80,7 @@ ReactDOM.createRoot(
 >
 >Concurrent Mode APIs such as `createRoot` only exist in the experimental builds of React.
 
-In Concurrent Mode, the lifecycle methods [previously marked](https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html) as "unsafe" actually *are* unsafe, and lead to bugs even more than in today's React. We don't recommend trying Concurrent Mode until your app is [Strict Mode](https://reactjs.org/docs/strict-mode.html)-compatible.
+In Concurrent Mode, the lifecycle methods [previously marked](/blog/2018/03/27/update-on-async-rendering.html) as "unsafe" actually *are* unsafe, and lead to bugs even more than in today's React. We don't recommend trying Concurrent Mode until your app is [Strict Mode](/docs/strict-mode.html)-compatible.
 
 ## What to Expect {#what-to-expect}
 
diff --git a/content/docs/concurrent-mode-patterns.md b/content/docs/concurrent-mode-patterns.md
@@ -507,7 +507,7 @@ function ProfileTrivia({ resource }) {
 
 **[Try it on CodeSandbox](https://codesandbox.io/s/focused-mountain-uhkzg)**
 
-If you press "Open Profile" now, you can tell something is wrong. It takes whole seven seconds to make the transition now! This is because our trivia API is too slow. Let's say we can't make the API faster. How can we improve the user experience with this constraint?
+If you press "Open Profile" now, you can tell something is wrong. It takes a whole seven seconds to make the transition now! This is because our trivia API is too slow. Let's say we can't make the API faster. How can we improve the user experience with this constraint?
 
 If we don't want to stay in the Pending state for too long, our first instinct might be to set `timeoutMs` in `useTransition` to something smaller, like `3000`. You can try this [here](https://codesandbox.io/s/practical-kowalevski-kpjg4). This lets us escape the prolonged Pending state, but we still don't have anything useful to show!
 
@@ -790,7 +790,7 @@ function ProfileTimeline({ isStale, resource }) {
 
 The tradeoff we're making here is that `<ProfileTimeline>` will be inconsistent with other components and potentially show an older item. Click "Next" a few times, and you'll notice it. But thanks to that, we were able to cut down the transition time from 1000ms to 300ms.
 
-Whether or not it's an appropriate tradeoff depends on the situation. But it's a handy tool, especially when the content doesn't change very visible between items, and the user might not even realize they were looking at a stale version for a second.
+Whether or not it's an appropriate tradeoff depends on the situation. But it's a handy tool, especially when the content doesn't change noticeably between items, and the user might not even realize they were looking at a stale version for a second.
 
 It's worth noting that `useDeferredValue` is not *only* useful for data fetching. It also helps when an expensive component tree causes an interaction (e.g. typing in an input) to be sluggish. Just like we can "defer" a value that takes too long to fetch (and show its old value despite others components updating), we can do this with trees that take too long to render.
 
diff --git a/content/docs/faq-versioning.md b/content/docs/faq-versioning.md
@@ -22,7 +22,7 @@ Minor releases are the most common type of release.
 
 ### Breaking Changes {#breaking-changes}
 
-Breaking changes are inconvenient for everyone, so we try to minimize the number of major releases – for example, React 15 was released in April 2016 and React 16 was released in September 2017; React 17 isn't expected until 2019.
+Breaking changes are inconvenient for everyone, so we try to minimize the number of major releases – for example, React 15 was released in April 2016 and React 16 was released in September 2017; React 17 isn't expected until sometime in 2020.
 
 Instead, we release new features in minor versions. That means that minor releases are often more interesting and compelling than majors, despite their unassuming name.
 
diff --git a/content/docs/hooks-reference.md b/content/docs/hooks-reference.md
@@ -143,7 +143,7 @@ Although `useEffect` is deferred until after the browser has painted, it's guara
 
 The default behavior for effects is to fire the effect after every completed render. That way an effect is always recreated if one of its dependencies changes.
 
-However, this may be overkill in some cases, like the subscription example from the previous section. We don't need to create a new subscription on every update, only if the `source` props has changed.
+However, this may be overkill in some cases, like the subscription example from the previous section. We don't need to create a new subscription on every update, only if the `source` prop has changed.
 
 To implement this, pass a second argument to `useEffect` that is the array of values that the effect depends on. Our updated example now looks like this:
 
diff --git a/content/docs/how-to-contribute.md b/content/docs/how-to-contribute.md
@@ -21,7 +21,7 @@ All work on React happens directly on [GitHub](https://github.com/facebook/react
 
 ### Semantic Versioning {#semantic-versioning}
 
-React follows [semantic versioning](https://semver.org/). We release patch versions for critical bugfixes, minor versions for new features or non-essential changes, and major versions for any breaking changes. When we make breaking changes, we also introduce deprecation warnings in a minor version so that our users learn about the upcoming changes and migrate their code in advance. Learn more about our commitment to stability and incremental migration in [our versioning policy](https://reactjs.org/docs/faq-versioning.html).
+React follows [semantic versioning](https://semver.org/). We release patch versions for critical bugfixes, minor versions for new features or non-essential changes, and major versions for any breaking changes. When we make breaking changes, we also introduce deprecation warnings in a minor version so that our users learn about the upcoming changes and migrate their code in advance. Learn more about our commitment to stability and incremental migration in [our versioning policy](/docs/faq-versioning.html).
 
 Every significant change is documented in the [changelog file](https://github.com/facebook/react/blob/master/CHANGELOG.md).
 
@@ -56,7 +56,7 @@ Facebook has a [bounty program](https://www.facebook.com/whitehat/) for the safe
 ### How to Get in Touch {#how-to-get-in-touch}
 
 * IRC: [#reactjs on freenode](https://webchat.freenode.net/?channels=reactjs)
-* [Discussion forums](https://reactjs.org/community/support.html#popular-discussion-forums)
+* [Discussion forums](/community/support.html#popular-discussion-forums)
 
 There is also [an active community of React users on the Discord chat platform](https://www.reactiflux.com/) in case you need help with React.
 
@@ -104,6 +104,7 @@ In order to accept your pull request, we need you to submit a CLA. You only need
 ### Contribution Prerequisites {#contribution-prerequisites}
 
 * You have [Node](https://nodejs.org) installed at v8.0.0+ and [Yarn](https://yarnpkg.com/en/) at v1.2.0+.
+* You have [JDK](https://www.oracle.com/technetwork/java/javase/downloads/index.html) installed.
 * You have `gcc` installed or are comfortable installing a compiler if needed. Some of our dependencies may require a compilation step. On OS X, the Xcode Command Line Tools will cover this. On Ubuntu, `apt-get install build-essential` will install the required packages. Similar commands should work on other Linux distros. Windows will require some additional steps, see the [`node-gyp` installation instructions](https://github.com/nodejs/node-gyp#installation) for details.
 * You are familiar with Git.
 
@@ -154,19 +155,6 @@ You can check the status of your code styling by simply running `yarn linc`.
 
 However, there are still some styles that the linter cannot pick up. If you are unsure about something, looking at [Airbnb's Style Guide](https://github.com/airbnb/javascript) will guide you in the right direction.
 
-### Introductory Video {#introductory-video}
-
-You may be interested in watching [this short video](https://www.youtube.com/watch?v=wUpPsEcGsg8) (26 mins) which gives an introduction on how to contribute to React.
-
-#### Video highlights: {#video-highlights}
-- [4:12](https://youtu.be/wUpPsEcGsg8?t=4m12s) - Building and testing React locally
-- [6:07](https://youtu.be/wUpPsEcGsg8?t=6m7s) - Creating and sending pull requests
-- [8:25](https://youtu.be/wUpPsEcGsg8?t=8m25s) - Organizing code
-- [14:43](https://youtu.be/wUpPsEcGsg8?t=14m43s) - React npm registry
-- [19:15](https://youtu.be/wUpPsEcGsg8?t=19m15s) - Adding new React features
-
-For a realistic overview of what it _feels_ like to contribute to React for the first time, check out [this entertaining ReactNYC talk](https://www.youtube.com/watch?v=GWCcZ6fnpn4).
-
 ### Request for Comments (RFC) {#request-for-comments-rfc}
 
 Many changes, including bug fixes and documentation improvements can be implemented and reviewed via the normal GitHub pull request workflow.
diff --git a/content/docs/react-without-jsx.md b/content/docs/react-without-jsx.md
@@ -40,7 +40,7 @@ ReactDOM.render(
 
 If you're curious to see more examples of how JSX is converted to JavaScript, you can try out [the online Babel compiler](babel://jsx-simple-example).
 
-The component can either be provided as a string, or as a subclass of `React.Component`, or a plain function for stateless components.
+The component can either be provided as a string, as a subclass of `React.Component`, or a plain function.
 
 If you get tired of typing `React.createElement` so much, one common pattern is to assign a shorthand:
 
diff --git a/content/docs/reconciliation.md b/content/docs/reconciliation.md
@@ -142,7 +142,7 @@ As a last resort, you can pass an item's index in the array as a key. This can w
 
 Reorders can also cause issues with component state when indexes are used as keys. Component instances are updated and reused based on their key. If the key is an index, moving an item changes it. As a result, component state for things like uncontrolled inputs can get mixed up and updated in unexpected ways.
 
-[Here](codepen://reconciliation/index-used-as-key) is an example of the issues that can be caused by using indexes as keys on CodePen, and [here](codepen://reconciliation/no-index-used-as-key) is an updated version of the same example showing how not using indexes as keys will fix these reordering, sorting, and prepending issues.
+Here is [an example of the issues that can be caused by using indexes as keys](codepen://reconciliation/index-used-as-key) on CodePen, and here is [an updated version of the same example showing how not using indexes as keys will fix these reordering, sorting, and prepending issues](codepen://reconciliation/no-index-used-as-key).
 
 ## Tradeoffs {#tradeoffs}
 
diff --git a/content/docs/reference-profiler.md b/content/docs/reference-profiler.md
@@ -7,11 +7,11 @@ permalink: docs/profiler.html
 ---
 
 The `Profiler` measures how often a React application renders and what the "cost" of rendering is.
-Its purpose is to help identify parts of an application that are slow and may benefit from [optimizations such as memoization](https://reactjs.org/docs/hooks-faq.html#how-to-memoize-calculations).
+Its purpose is to help identify parts of an application that are slow and may benefit from [optimizations such as memoization](/docs/hooks-faq.html#how-to-memoize-calculations).
 
 > Note:
 >
-> Profiling adds some additional overhead, so **it is disabled in [the production build](https://reactjs.org/docs/optimizing-performance.html#use-the-production-build)**.
+> Profiling adds some additional overhead, so **it is disabled in [the production build](/docs/optimizing-performance.html#use-the-production-build)**.
 >
 > To opt into production profiling, React provides a special production build with profiling enabled.
 > Read more about how to use this build at [fb.me/react-profiling](https://fb.me/react-profiling)
diff --git a/content/docs/refs-and-the-dom.md b/content/docs/refs-and-the-dom.md
@@ -161,7 +161,7 @@ class Parent extends React.Component {
 }
 ```
 
-If you want to allow people to take a `ref` to your function component, you can use [`forwardRef`](https://reactjs.org/docs/forwarding-refs.html) (possibly in conjunction with [`useImperativeHandle`](/docs/hooks-reference.html#useimperativehandle)), or you can convert the component to a class.
+If you want to allow people to take a `ref` to your function component, you can use [`forwardRef`](/docs/forwarding-refs.html) (possibly in conjunction with [`useImperativeHandle`](/docs/hooks-reference.html#useimperativehandle)), or you can convert the component to a class.
 
 You can, however, **use the `ref` attribute inside a function component** as long as you refer to a DOM element or a class component:
 
diff --git a/content/docs/static-type-checking.md b/content/docs/static-type-checking.md
@@ -175,7 +175,7 @@ Create React App supports TypeScript out of the box.
 To create a **new project** with TypeScript support, run:
 
 ```bash
-npx create-react-app my-app --typescript
+npx create-react-app my-app --template typescript
 ```
 
 You can also add it to an **existing Create React App project**, [as documented here](https://facebook.github.io/create-react-app/docs/adding-typescript).
diff --git a/content/docs/strict-mode.md b/content/docs/strict-mode.md
diff --git a/content/docs/testing-environments.md b/content/docs/testing-environments.md
diff --git a/content/tutorial/tutorial.md b/content/tutorial/tutorial.md

Original file line number	Diff line number	Diff line change
`@@ -18,4 +18,4 @@ There are many wonderful curated resources the React community has put together.`
`18`	`18`
`19`	`19`	`- [Awesome React Talks](https://github.com/tiaanduplessis/awesome-react-talks) - A curated list of React talks.`
`20`	`20`
`21`		`-- [Hero35 React Hub](https://hero35.com/stack/react) - A website with _all_ React conferences and talks, categorized & curated.`
	`21`	`+- [Hero35 React Hub](https://hero35.com/topic/react) - A website with _all_ React conferences and talks, categorized & curated.`
Original file line number	Diff line number	Diff line change
`@@ -80,7 +80,7 @@ ReactDOM.createRoot(`
`80`	`80`	`>`
`81`	`81`	>Concurrent Mode APIs such as `createRoot` only exist in the experimental builds of React.
`82`	`82`
`83`		`-In Concurrent Mode, the lifecycle methods [previously marked](https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html) as "unsafe" actually are unsafe, and lead to bugs even more than in today's React. We don't recommend trying Concurrent Mode until your app is [Strict Mode](https://reactjs.org/docs/strict-mode.html)-compatible.`
	`83`	`+In Concurrent Mode, the lifecycle methods [previously marked](/blog/2018/03/27/update-on-async-rendering.html) as "unsafe" actually are unsafe, and lead to bugs even more than in today's React. We don't recommend trying Concurrent Mode until your app is [Strict Mode](/docs/strict-mode.html)-compatible.`
`84`	`84`
`85`	`85`	`## What to Expect {#what-to-expect}`
`86`	`86`