Merge changes from master into Gatsby branch (#10853)

* Update changelog for unreleased 16.0 changes (#10730) * First shot at updating changelog for 16.0 **what is the change?:** Added an 'unreleased' section to the changelog with info from #10294 **why make this change?:** To get things set for the 16.0 release. **test plan:** Visual inspection **issue:** #8854 * Fix typos and formatting errors in changelog * Add requestAnimationFrame and remove "New helpful warnings" **what is the change?:** In response to helpful code review - - Add mention of dependency on `requestAnimationFrame` and need to polyfill that as well as `Map` and `Set` - Remove "New helpful warnings" section; it was incomplete, and there are so many new and updated warnings that it might not be reasonable to cover them in the changelog. **why make this change?:** Accuracy **test plan:** Visual inspection **issue:** issue #8854 * Improve wording * Improve wording and fix missing links * Add backticks to file names & code; wording tweak * Break "Major Changes" into "New Feature" and "Breaking Changes" * Add server side render changes to 16.0 changelog * Change gist link from mine to gaearons * Add note about returning fragments * fix misc nits * Misc. formatting/wording fixes to changelog **what is the change?:** Thanks to the kind code review comments of @gaearon and @nhunzaker we have - removed the non-deterministic bold styling on some bullet points - improved wording of the bullet points for portals, attribute whitelist changes, and server rendering changes - Add note about error boundaries including a breaking change to error handling behavior. - punctuation and capitalization fixes **why make this change?:** Clarity and correctness **test plan:** Visual inspection **issue:** #8854 * fix broken link * Fixes #9667: Updated createTextInstance to create the text node on correct document (#10723) * Record sizes * Add a changelog for elements having the same key (#10811) * Add a changelog for elements having the same key * Reword * Markdown fixs on "DOM Attributes in React 16" post (#10816) * Include tag name into the table snapshot (#10818) * Update DOM warning wording and link (#10819) * Update DOM warning wording and link * Consistently use "Invalid" for known misspellings * Update license headers BSD+Patents -> MIT Did find and replace in TextMate. ``` find: (?:( \*)( ))?Copyright (?:$c$ )?(\d{4})\b.+Facebook[\s\S]+(?:this source tree|the same directory)\.$ replace: $1$2Copyright (c) $3-present, Facebook, Inc.\n$1\n$1$2This source code is licensed under the MIT license found in the\n$1$2LICENSE file in the root directory of this source tree. ``` * Change license and remove references to PATENTS Only remaining references: ``` docs/_posts/2014-10-28-react-v0.12.md 51:You can read the full text of the [LICENSE](https://github.com/facebook/react/blob/master/LICENSE) and [`PATENTS`](https://github.com/facebook/react/blob/master/PATENTS) files on GitHub. docs/_posts/2015-04-17-react-native-v0.4.md 20:* **Patent Grant**: Many of you had concerns and questions around the PATENTS file. We pushed [a new version of the grant](https://code.facebook.com/posts/1639473982937255/updating-our-open-source-patent-grant/). src/__mocks__/vendor/third_party/WebComponents.js 8: * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt ``` * Version bumps to use MIT license * Add ReactTestRenderer documentations (#10692) * Add ReactTestRenderer documentations * Add TestRenderer documentations * TestRenderer is not experiment * Add a link for jsdom * Use ES Modules syntax * Twaek * Add a Link component * Use Jest assertions * Move a documentation for createNodeMock to Idea section * Renamed * Tweak * Rename * More explicit * Add a usecase for createNodeMock * Add changelog for 15.6.2 * Add 15.6.2 blog post to master * Add Nate to authors on master * Bump object-assign patch range to match main package.json * Flow should ignore node_modules/create-react-class * Update error codes * Update CHANGELOG for React 16 * v16.0.0 * Doc updates for React 16 + blog post (#10824) * Doc updates for React 16 + blog post * Add link to Sophie's post * Fix React links on the website (#10837) * Fix React links on the website * Fix code editor * Fix code editor, attempt 2 * Doc change for prevContext removal in CDU (#10836) * Doc change for prevContext removal in CDU Ref: #8631 * Minor rewording * Fix note formatting * React.createPortal is not a function (#10843) * Update Portals Documentation (#10840) * Update Portals Documentation Correct some grammar to be more explicit and clear. Update example CodePen to better match code found in documentation. Update code example styles to match other code examples (ie. 'State and Lifecycle', 'Handling Events'). * Clean up comment to be accurate to example There was a small comment overlooked when reviewing the documentation. This fixes it to be accurate to the example as well as grammatically correct. * Update portals.md * More fixes * Update name of property initializer proposal (#10812) The proposal for property initializers is called [Public Class Fields](https://tc39.github.io/proposal-class-public-fields/) now (part of the combined [Class Fields](https://github.com/tc39/proposal-class-fields) proposal). * Fix portal link (#10845) * Update docs for React 16 (#10846) * Minor doc edit * Rename urls
facebook · bvaughn · Sep 28, 2017 · Jun 30, 2017 · Jun 30, 2017 · Jun 30, 2017
commit 2b317d19b174aa25717b938ee61f18263a84517b
diff --git a/.flowconfig b/.flowconfig
@@ -7,6 +7,7 @@
 <PROJECT_ROOT>/node_modules/chrome-devtools-frontend/.*
 <PROJECT_ROOT>/node_modules/devtools-timeline-model/.*
 <PROJECT_ROOT>/www/node_modules/.*
+<PROJECT_ROOT>/node_modules/create-react-class/.*
 <PROJECT_ROOT>/.*/__mocks__/.*
 <PROJECT_ROOT>/.*/__tests__/.*
 

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,12 @@
     Click to see more.
   </summary>
 
+No unreleased changes yet.
+
+</details>
+
+## 16.0.0 (September 26, 2017)
+
 ### New JS Environment Requirements
 
  * React 16 depends on the collection types [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) and [Set](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set), as well as [requestAnimationFrame](https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame). If you support older browsers and devices which may not yet provide these natively (e.g. <IE11), [you may want to include a polyfill](https://gist.github.com/gaearon/9a4d54653ae9c50af6c54b4e0e56b583).
@@ -47,8 +53,6 @@
 - There is no `react-with-addons.js` build anymore. All compatible addons are published separately on npm, and have single-file browser versions if you need them.
 - The deprecations introduced in 15.x have been removed from the core package. `React.createClass` is now available as create-react-class, `React.PropTypes` as prop-types, `React.DOM` as react-dom-factories, react-addons-test-utils as react-dom/test-utils, and shallow renderer as react-test-renderer/shallow. See [15.5.0](https://facebook.github.io/react/blog/2017/04/07/react-v15.5.0.html) and [15.6.0](https://facebook.github.io/react/blog/2017/06/13/react-v15.6.0.html) blog posts for instructions on migrating code and automated codemods.
 
-</details>
-
 ## 15.6.2 (September 25, 2017)
 
 ### All Packages

diff --git a/docs/_config.yml b/docs/_config.yml
@@ -60,7 +60,7 @@ sass:
 gems:
 - jekyll-redirect-from
 - jekyll-paginate
-react_version: 15.4.0
+react_version: 16.0.0
 react_hashes:
   dev: buVLzxzBI8Ps3svVMSUurNdb5dozNidH5Ow4H0YgZeia3t6Oeui2VLpvtAq1fwtK
   prod: nCjsa0kjNQPQdxWm12/ReVJzfBJaVubEwwDswyQDGMKYJmeWv3qShMuETfU5fisu

diff --git a/docs/_data/nav_docs.yml b/docs/_data/nav_docs.yml
@@ -46,6 +46,8 @@
       title: Reconciliation
     - id: context
       title: Context
+    - id: portals
+      title: Portals
     - id: web-components
       title: Web Components
     - id: higher-order-components
@@ -65,8 +67,6 @@
       title: ReactDOM
     - id: react-dom-server
       title: ReactDOMServer
-    - id: react-dom-node-stream
-      title: ReactDOMNodeStream
     - id: dom-elements
       title: DOM Elements
     - id: events
@@ -77,3 +77,5 @@
       title: Shallow Renderer
     - id: test-renderer
       title: Test Renderer
+    - id: javascript-environment-requirements
+      title: JS Environment Requirements
diff --git a/docs/_js/live_editor.js b/docs/_js/live_editor.js
@@ -8,7 +8,7 @@ var IS_MOBILE = (
     || navigator.userAgent.match(/Windows Phone/i)
 );
 
-var CodeMirrorEditor = React.createClass({
+var CodeMirrorEditor = createReactClass({
   propTypes: {
     lineNumbers: PropTypes.bool,
     onChange: PropTypes.func,
@@ -74,7 +74,7 @@ var selfCleaningTimeout = {
   },
 };
 
-var ReactPlayground = React.createClass({
+var ReactPlayground = createReactClass({
   mixins: [selfCleaningTimeout],
 
   MODES: {JSX: 'JSX', JS: 'JS'}, //keyMirror({JSX: true, JS: true}),

diff --git a/docs/_layouts/default.html b/docs/_layouts/default.html
@@ -49,8 +49,9 @@
   <script src="https://unpkg.com/codemirror@5.15.2/mode/xml/xml.js"></script>
   <script src="https://unpkg.com/codemirror@5.15.2/mode/jsx/jsx.js"></script>
   <script src="https://unpkg.com/prop-types/prop-types.min.js"></script>
-  <script src="https://unpkg.com/react/dist/react.min.js"></script>
-  <script src="https://unpkg.com/react-dom/dist/react-dom.min.js"></script>
+  <script src="https://unpkg.com/react/umd/react.production.min.js"></script>
+  <script src="https://unpkg.com/react-dom/umd/react-dom.production.min.js"></script>
+  <script src="https://unpkg.com/create-react-class/create-react-class.min.js"></script>
   <script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
   <script src="/react/js/live_editor.js"></script>
 </head>

diff --git a/docs/_posts/2013-06-05-why-react.md b/docs/_posts/2013-06-05-why-react.md
@@ -30,7 +30,7 @@ to render views, which we see as an advantage over templates for a few reasons:
   **no manual string concatenation** and therefore less surface area for XSS
   vulnerabilities.
 
-We've also created [JSX](/react/docs/jsx-in-depth.html), an optional syntax
+We've also created [JSX](/docs/jsx-in-depth.html), an optional syntax
 extension, in case you prefer the readability of HTML to raw JavaScript.
 
 ## Reactive updates are dead simple.

diff --git a/docs/_posts/2013-06-12-community-roundup.md b/docs/_posts/2013-06-12-community-roundup.md
@@ -38,7 +38,7 @@ It looks like [Sophie Alpert](http://sophiebits.com/) is the first person outsid
 
 ## Origins of React
 
-[Pete Hunt](http://www.petehunt.net/blog/) explained what differentiates React from other JavaScript libraries in [a previous blog post](/react/blog/2013/06/05/why-react.html). [Lee Byron](http://leebyron.com/) gives another perspective on Quora:
+[Pete Hunt](http://www.petehunt.net/blog/) explained what differentiates React from other JavaScript libraries in [a previous blog post](/blog/2013/06/05/why-react.html). [Lee Byron](http://leebyron.com/) gives another perspective on Quora:
 
 > React isn't quite like any other popular JavaScript libraries, and it solves a very specific problem: complex UI rendering. It's also intended to be used along side many other popular libraries. For example, React works well with Backbone.js, amongst many others.
 >

diff --git a/docs/_posts/2013-06-19-community-roundup-2.md b/docs/_posts/2013-06-19-community-roundup-2.md
@@ -64,7 +64,7 @@ Mozilla and Google are actively working on Web Components. [Vjeux](http://blog.v
 
 Many of you pointed out differences between JSX and HTML. In order to clear up some confusion, we have added some documentation that covers the four main differences:
 
-  - [Whitespace removal](/react/docs/jsx-is-not-html.html)
-  - [HTML Entities](/react/docs/jsx-is-not-html.html)
-  - [Comments](/react/docs/jsx-is-not-html.html)
-  - [Custom HTML Attributes](/react/docs/jsx-is-not-html.html)
+  - [Whitespace removal](/docs/jsx-is-not-html.html)
+  - [HTML Entities](/docs/jsx-is-not-html.html)
+  - [Comments](/docs/jsx-is-not-html.html)
+  - [Custom HTML Attributes](/docs/jsx-is-not-html.html)
diff --git a/docs/_posts/2013-07-03-community-roundup-4.md b/docs/_posts/2013-07-03-community-roundup-4.md
@@ -23,7 +23,7 @@ The best part is the demo of how React reconciliation process makes live editing
 
 ## React Snippets
 
-Over the past several weeks, members of our team, [Pete Hunt](http://www.petehunt.net/) and [Paul O'Shannessy](http://zpao.com/), answered many questions that were asked in the [React group](https://groups.google.com/forum/#!forum/reactjs). They give a good overview of how to integrate React with other libraries and APIs through the use of [Mixins](/react/docs/reusable-components.html) and [Lifecycle Methods](/react/docs/working-with-the-browser.html).
+Over the past several weeks, members of our team, [Pete Hunt](http://www.petehunt.net/) and [Paul O'Shannessy](http://zpao.com/), answered many questions that were asked in the [React group](https://groups.google.com/forum/#!forum/reactjs). They give a good overview of how to integrate React with other libraries and APIs through the use of [Mixins](/docs/reusable-components.html) and [Lifecycle Methods](/docs/working-with-the-browser.html).
 
 > [Listening Scroll Event](https://groups.google.com/forum/#!topic/reactjs/l6PnP8qbofk)
 >

diff --git a/docs/_posts/2013-07-17-react-v0-4-0.md b/docs/_posts/2013-07-17-react-v0-4-0.md
@@ -18,10 +18,10 @@ When you're ready, [go download it](/react/downloads.html)!
 * Switch from using `id` attribute to `data-reactid` to track DOM nodes. This allows you to integrate with other JS and CSS libraries more easily.
 * Support for more DOM elements and attributes (e.g., `<canvas>`)
 * Improved server-side rendering APIs. `React.renderComponentToString(<component>, callback)` allows you to use React on the server and generate markup which can be sent down to the browser.
-* `prop` improvements: validation and default values. [Read our blog post for details...](/react/blog/2013/07/11/react-v0-4-prop-validation-and-default-values.html)
-* Support for the `key` prop, which allows for finer control over reconciliation. [Read the docs for details...](/react/docs/multiple-components.html)
-* Removed `React.autoBind`. [Read our blog post for details...](/react/blog/2013/07/02/react-v0-4-autobind-by-default.html)
-* Improvements to forms. We've written wrappers around `<input>`, `<textarea>`, `<option>`, and `<select>` in order to standardize many inconsistencies in browser implementations. This includes support for `defaultValue`, and improved implementation of the `onChange` event, and circuit completion. [Read the docs for details...](/react/docs/forms.html)
+* `prop` improvements: validation and default values. [Read our blog post for details...](/blog/2013/07/11/react-v0-4-prop-validation-and-default-values.html)
+* Support for the `key` prop, which allows for finer control over reconciliation. [Read the docs for details...](/docs/multiple-components.html)
+* Removed `React.autoBind`. [Read our blog post for details...](/blog/2013/07/02/react-v0-4-autobind-by-default.html)
+* Improvements to forms. We've written wrappers around `<input>`, `<textarea>`, `<option>`, and `<select>` in order to standardize many inconsistencies in browser implementations. This includes support for `defaultValue`, and improved implementation of the `onChange` event, and circuit completion. [Read the docs for details...](/docs/forms.html)
 * We've implemented an improved synthetic event system that conforms to the W3C spec.
 * Updates to your component are batched now, which may result in a significantly faster re-render of components. `this.setState` now takes an optional callback as its second parameter. If you were using `onClick={this.setState.bind(this, state)}` previously, you'll want to make sure you add a third parameter so that the event is not treated as the callback.
 

diff --git a/docs/_posts/2013-07-23-community-roundup-5.md b/docs/_posts/2013-07-23-community-roundup-5.md
@@ -84,15 +84,15 @@ React.renderComponent(
 
 > Guides
 >
-> * [Why React?](/react/docs/why-react.html)
-> * [Displaying Data](/react/docs/displaying-data.html)
->   * [JSX in Depth](/react/docs/jsx-in-depth.html)
->   * [JSX Gotchas](/react/docs/jsx-gotchas.html)
-> * [Interactivity and Dynamic UIs](/react/docs/interactivity-and-dynamic-uis.html)
-> * [Multiple Components](/react/docs/multiple-components.html)
-> * [Reusable Components](/react/docs/reusable-components.html)
-> * [Forms](/react/docs/forms.html)
-> * [Working With the Browser](/react/docs/working-with-the-browser.html)
->   * [More About Refs](/react/docs/more-about-refs.html)
-> * [Tooling integration](/react/docs/tooling-integration.html)
-> * [Reference](/react/docs/top-level-api.html)
+> * [Why React?](/docs/why-react.html)
+> * [Displaying Data](/docs/displaying-data.html)
+>   * [JSX in Depth](/docs/jsx-in-depth.html)
+>   * [JSX Gotchas](/docs/jsx-gotchas.html)
+> * [Interactivity and Dynamic UIs](/docs/interactivity-and-dynamic-uis.html)
+> * [Multiple Components](/docs/multiple-components.html)
+> * [Reusable Components](/docs/reusable-components.html)
+> * [Forms](/docs/forms.html)
+> * [Working With the Browser](/docs/working-with-the-browser.html)
+>   * [More About Refs](/docs/more-about-refs.html)
+> * [Tooling integration](/docs/tooling-integration.html)
+> * [Reference](/docs/top-level-api.html)
diff --git a/docs/_posts/2013-08-26-community-roundup-7.md b/docs/_posts/2013-08-26-community-roundup-7.md
@@ -10,7 +10,7 @@ It's been three months since we open sourced React and it is going well. Some st
 * [226 posts on Google Group](https://groups.google.com/forum/#!forum/reactjs)
 * [76 GitHub projects using React](https://gist.github.com/vjeux/6335762)
 * [30 contributors](https://github.com/facebook/react/graphs/contributors)
-* [15 blog posts](/react/blog/)
+* [15 blog posts](/blog/)
 * 2 early adopters: [Khan Academy](http://sophiebits.com/2013/06/09/using-react-to-speed-up-khan-academy.html) and [Propeller](http://usepropeller.com/blog/posts/from-backbone-to-react/)
 
 

diff --git a/docs/_posts/2013-10-16-react-v0.5.0.md b/docs/_posts/2013-10-16-react-v0.5.0.md
@@ -7,7 +7,7 @@ This release is the result of several months of hard work from members of the te
 
 The biggest change you'll notice as a developer is that we no longer support `class` in JSX as a way to provide CSS classes. Since this prop was being converted to `className` at the transform step, it caused some confusion when trying to access it in composite components. As a result we decided to make our DOM properties mirror their counterparts in the JS DOM API. There are [a few exceptions](https://github.com/facebook/react/blob/master/src/dom/DefaultDOMPropertyConfig.js#L156) where we deviate slightly in an attempt to be consistent internally.
 
-The other major change in v0.5 is that we've added an additional build - `react-with-addons` - which adds support for some extras that we've been working on including animations and two-way binding. [Read more about these addons in the docs](/react/docs/addons.html).
+The other major change in v0.5 is that we've added an additional build - `react-with-addons` - which adds support for some extras that we've been working on including animations and two-way binding. [Read more about these addons in the docs](/docs/addons.html).
 
 ## Thanks to Our Community
 
@@ -41,7 +41,7 @@ It's been awesome to see the things that people are building with React, and we
 
 ### React with Addons (New!)
 
-* Introduced a separate build with several "addons" which we think can help improve the React experience. We plan to deprecate this in the long-term, instead shipping each as standalone pieces. [Read more in the docs](/react/docs/addons.html).
+* Introduced a separate build with several "addons" which we think can help improve the React experience. We plan to deprecate this in the long-term, instead shipping each as standalone pieces. [Read more in the docs](/docs/addons.html).
 
 ### JSX
 

diff --git a/docs/_posts/2013-12-23-community-roundup-12.md b/docs/_posts/2013-12-23-community-roundup-12.md
@@ -3,11 +3,11 @@ title: "Community Round-up #12"
 author: [vjeux]
 ---
 
-React got featured on the front-page of Hacker News thanks to the Om library. If you try it out for the first time, take a look at the [docs](/react/docs/getting-started.html) and do not hesitate to ask questions on the [Google Group](https://groups.google.com/group/reactjs), [IRC](irc://chat.freenode.net/reactjs) or [Stack Overflow](http://stackoverflow.com/questions/tagged/reactjs). We are trying our best to help you out!
+React got featured on the front-page of Hacker News thanks to the Om library. If you try it out for the first time, take a look at the [docs](/docs/getting-started.html) and do not hesitate to ask questions on the [Google Group](https://groups.google.com/group/reactjs), [IRC](irc://chat.freenode.net/reactjs) or [Stack Overflow](http://stackoverflow.com/questions/tagged/reactjs). We are trying our best to help you out!
 
 ## The Future of JavaScript MVC
 
-[David Nolen](https://swannodette.github.io/) announced Om, a thin wrapper on-top of React in ClojureScript. It stands out by only using immutable data structures. This unlocks the ability to write a very efficient [shouldComponentUpdate](/react/docs/component-specs.html#updating-shouldcomponentupdate) and get huge performance improvements on some tasks.
+[David Nolen](https://swannodette.github.io/) announced Om, a thin wrapper on-top of React in ClojureScript. It stands out by only using immutable data structures. This unlocks the ability to write a very efficient [shouldComponentUpdate](/docs/component-specs.html#updating-shouldcomponentupdate) and get huge performance improvements on some tasks.
 
 > We've known this for some time over here in the ClojureScript corner of the world - all of our collections are immutable and modeled directly on the original Clojure versions written in Java. Modern JavaScript engines have now been tuned to the point that it's no longer uncommon to see collection performance within 2.5X of the Java Virtual Machine.
 >
@@ -22,7 +22,7 @@ React got featured on the front-page of Hacker News thanks to the Om library. If
 
 ## Scroll Position with React
 
-Managing the scroll position when new content is inserted is usually very tricky to get right. [Vjeux](http://blog.vjeux.com/) discovered that [componentWillUpdate](/react/docs/component-specs.html#updating-componentwillupdate) and [componentDidUpdate](/react/docs/component-specs.html#updating-componentdidupdate) were triggered exactly at the right time to manage the scroll position.
+Managing the scroll position when new content is inserted is usually very tricky to get right. [Vjeux](http://blog.vjeux.com/) discovered that [componentWillUpdate](/docs/component-specs.html#updating-componentwillupdate) and [componentDidUpdate](/docs/component-specs.html#updating-componentdidupdate) were triggered exactly at the right time to manage the scroll position.
 
 > We can check the scroll position before the component has updated with componentWillUpdate and scroll if necessary at componentDidUpdate
 >
@@ -45,7 +45,7 @@ Managing the scroll position when new content is inserted is usually very tricky
 
 ## Lights Out
 
-React declarative approach is well suited to write games. [Cheng Lou](https://github.com/chenglou) wrote the famous Lights Out game in React. It's a good example of use of [TransitionGroup](/react/docs/animation.html) to implement animations.
+React declarative approach is well suited to write games. [Cheng Lou](https://github.com/chenglou) wrote the famous Lights Out game in React. It's a good example of use of [TransitionGroup](/docs/animation.html) to implement animations.
 <figure><a href="https://chenglou.github.io/react-lights-out/"><img src="../img/blog/lights-out.png"></a></figure>
 
 [Try it out!](https://chenglou.github.io/react-lights-out/)

diff --git a/docs/_posts/2014-02-20-react-v0.9.md b/docs/_posts/2014-02-20-react-v0.9.md
@@ -24,7 +24,7 @@ We've also published version `0.9.0` of the `react` and `react-tools` packages o
 
 This version includes better support for normalizing event properties across all supported browsers so that you need to worry even less about cross-browser differences. We've also made many improvements to error messages and have refactored the core to never rethrow errors, so stack traces are more accurate and Chrome's purple break-on-error stop sign now works properly.
 
-We've also added to the add-ons build [React.addons.TestUtils](/react/docs/test-utils.html), a set of new utilities to help you write unit tests for React components. You can now simulate events on your components, and several helpers are provided to help make assertions about the rendered DOM tree.
+We've also added to the add-ons build [React.addons.TestUtils](/docs/test-utils.html), a set of new utilities to help you write unit tests for React components. You can now simulate events on your components, and several helpers are provided to help make assertions about the rendered DOM tree.
 
 We've also made several other improvements and a few breaking changes; the full changelog is provided below.