Updated scripts and config to replace "master" with "main" branch (#21768)

.circleci/config.yml

@@ -171,9 +171,9 @@ jobs:
       - run:
           name: Download artifacts for base revision
           command: |
-              git fetch origin master
+              git fetch origin main
               cd ./scripts/release && yarn && cd ../../
-              scripts/release/download-experimental-build.js --commit=$(git merge-base HEAD origin/master)
+              scripts/release/download-experimental-build.js --commit=$(git merge-base HEAD origin/main)
               mv ./build2 ./base-build
       - persist_to_workspace:
           root: .
@@ -356,7 +356,7 @@ jobs:
       - run:
           name: Run publish script
           command: |
-            git fetch origin master
+            git fetch origin main
             cd ./scripts/release && yarn && cd ../../
             scripts/release/prepare-release-from-ci.js --skipTests -r << parameters.release_channel >> --commit=<< parameters.commit_sha >>
             cp ./scripts/release/ci-npmrc ~/.npmrc
@@ -414,7 +414,7 @@ workflows:
           filters:
             branches:
               only:
-                - master
+                - main
 
   # New workflow that will replace "stable" and "experimental"
   build_and_test:
@@ -491,14 +491,14 @@ workflows:
           filters:
             branches:
               ignore:
-                - master
+                - main
           requires:
             - setup
       - sizebot:
           filters:
             branches:
               ignore:
-                - master
+                - main
           requires:
             - get_base_build
             - yarn_build_combined
@@ -514,7 +514,7 @@ workflows:
           filters:
             branches:
               only:
-                - master
+                - main
     jobs:
       - setup
       - test_fuzz:
@@ -555,7 +555,7 @@ workflows:
           filters:
             branches:
               only:
-                - master
+                - main
     jobs:
       - setup
       - publish_prerelease:

.github/PULL_REQUEST_TEMPLATE.md

@@ -4,7 +4,7 @@
 
   Before submitting a pull request, please make sure the following is done:
 
-  1. Fork [the repository](https://github.com/facebook/react) and create your branch from `master`.
+  1. Fork [the repository](https://github.com/facebook/react) and create your branch from `main`.
   2. Run `yarn` in the repository root.
   3. If you've fixed a bug or added code that should be tested, add tests!
   4. Ensure the test suite passes (`yarn test`). Tip: `yarn test --watch TestName` is helpful in development.

CHANGELOG.md

@@ -679,7 +679,7 @@ This release was published in a broken state and should be skipped.
 
 ### React Is (New)
 
-* First release of the [new package](https://github.com/facebook/react/tree/master/packages/react-is) that libraries can use to detect different React node types. ([@bvaughn](https://github.com/bvaughn) in [#12199](https://github.com/facebook/react/pull/12199))
+* First release of the [new package](https://github.com/facebook/react/tree/main/packages/react-is) that libraries can use to detect different React node types. ([@bvaughn](https://github.com/bvaughn) in [#12199](https://github.com/facebook/react/pull/12199))
 * Add `ReactIs.isValidElementType()` to help higher-order components validate their inputs. ([@jamesreggio](https://github.com/jamesreggio) in [#12483](https://github.com/facebook/react/pull/12483))
 
 ### React Lifecycles Compat (New)
@@ -688,7 +688,7 @@ This release was published in a broken state and should be skipped.
 
 ### Create Subscription (New)
 
-* First release of the [new package](https://github.com/facebook/react/tree/master/packages/create-subscription) to subscribe to external data sources safely for async rendering. ([@bvaughn](https://github.com/bvaughn) in [#12325](https://github.com/facebook/react/pull/12325))
+* First release of the [new package](https://github.com/facebook/react/tree/main/packages/create-subscription) to subscribe to external data sources safely for async rendering. ([@bvaughn](https://github.com/bvaughn) in [#12325](https://github.com/facebook/react/pull/12325))
 
 ### React Reconciler (Experimental)
 
@@ -819,12 +819,12 @@ Starting with 16.1.0, we will no longer be publishing new releases on Bower. You
 
 ### React Reconciler (Experimental)
 
-* First release of the [new experimental package](https://github.com/facebook/react/blob/master/packages/react-reconciler/README.md) for creating custom renderers. ([@iamdustan](https://github.com/iamdustan) in [#10758](https://github.com/facebook/react/pull/10758))
+* First release of the [new experimental package](https://github.com/facebook/react/blob/main/packages/react-reconciler/README.md) for creating custom renderers. ([@iamdustan](https://github.com/iamdustan) in [#10758](https://github.com/facebook/react/pull/10758))
 * Add support for React DevTools. ([@gaearon](https://github.com/gaearon) in [#11463](https://github.com/facebook/react/pull/11463))
 
 ### React Call Return (Experimental)
 
-* First release of the [new experimental package](https://github.com/facebook/react/tree/master/packages/react-call-return) for parent-child communication. ([@gaearon](https://github.com/gaearon) in [#11364](https://github.com/facebook/react/pull/11364))
+* First release of the [new experimental package](https://github.com/facebook/react/tree/main/packages/react-call-return) for parent-child communication. ([@gaearon](https://github.com/gaearon) in [#11364](https://github.com/facebook/react/pull/11364))
 
 ## 16.0.1 (August 1, 2018)
 

README.md

@@ -1,4 +1,4 @@
-# [React](https://reactjs.org/) · [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/facebook/react/blob/master/LICENSE) [![npm version](https://img.shields.io/npm/v/react.svg?style=flat)](https://www.npmjs.com/package/react) [![CircleCI Status](https://circleci.com/gh/facebook/react.svg?style=shield&circle-token=:circle-token)](https://circleci.com/gh/facebook/react) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](https://reactjs.org/docs/how-to-contribute.html#your-first-pull-request)
+# [React](https://reactjs.org/) · [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/facebook/react/blob/main/LICENSE) [![npm version](https://img.shields.io/npm/v/react.svg?style=flat)](https://www.npmjs.com/package/react) [![CircleCI Status](https://circleci.com/gh/facebook/react.svg?style=shield&circle-token=:circle-token)](https://circleci.com/gh/facebook/react) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](https://reactjs.org/docs/how-to-contribute.html#your-first-pull-request)
 
 React is a JavaScript library for building user interfaces.
 

appveyor.yml

@@ -18,7 +18,7 @@ platform:
 
 branches:
   only:
-    - master
+    - main
 
 # Disable Visual Studio build and deploy
 build: off

packages/create-subscription/README.md

@@ -8,7 +8,7 @@ This utility should be used for subscriptions to a single value that are typical
 
 Other cases have **better long-term solutions**:
 * Redux/Flux stores should use the [context API](https://reactjs.org/docs/context.html) instead.
-* I/O subscriptions (e.g. notifications) that update infrequently should use [`react-cache`](https://github.com/facebook/react/blob/master/packages/react-cache/README.md) instead.
+* I/O subscriptions (e.g. notifications) that update infrequently should use [`react-cache`](https://github.com/facebook/react/blob/main/packages/react-cache/README.md) instead.
 * Complex libraries like Relay/Apollo should manage subscriptions manually with the same techniques which this library uses under the hood (as referenced [here](https://gist.github.com/bvaughn/d569177d70b50b58bff69c3c4a5353f3)) in a way that is most optimized for their library usage.
 
 ## Limitations in async mode

packages/eslint-plugin-react-hooks/CHANGELOG.md

@@ -71,4 +71,4 @@
 
 ## 1.x
 
-The 1.x releases aren’t noted in this changelog, but you can find them in the [commit history](https://github.com/facebook/react/commits/master/packages/eslint-plugin-react-hooks).
+The 1.x releases aren’t noted in this changelog, but you can find them in the [commit history](https://github.com/facebook/react/commits/main/packages/eslint-plugin-react-hooks).

packages/react-devtools-extensions/flow-typed/npm/react-test-renderer_v16.x.x.js

@@ -2,7 +2,7 @@
 // flow-typed version: 9c71eca8ef/react-test-renderer_v16.x.x/flow_>=v0.47.x
 
 // Type definitions for react-test-renderer 16.x.x
-// Ported from: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/react-test-renderer
+// Ported from: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/main/types/react-test-renderer
 
 'use strict';
 

packages/react-devtools-extensions/popups/disabled.html

@@ -13,5 +13,5 @@
 <p>
   <b>This page doesn&rsquo;t appear to be using React.</b>
   <br />
-  If this seems wrong, follow the <a href="https://github.com/facebook/react/tree/master/packages/react-devtools#the-react-tab-doesnt-show-up">troubleshooting instructions</a>.
+  If this seems wrong, follow the <a href="https://github.com/facebook/react/tree/main/packages/react-devtools#the-react-tab-doesnt-show-up">troubleshooting instructions</a>.
 </p>

packages/react-devtools-inline/README.md

@@ -211,4 +211,4 @@ Once the above packages have been built or downloaded, you can watch for changes
 yarn start
 ```
 
-To test package changes, refer to the [`react-devtools-shell` README](https://github.com/facebook/react/blob/master/packages/react-devtools-shell/README.md).
+To test package changes, refer to the [`react-devtools-shell` README](https://github.com/facebook/react/blob/main/packages/react-devtools-shell/README.md).

packages/react-devtools-scheduling-profiler/src/view-base/utils/normalizeWheel.js

@@ -7,7 +7,7 @@
  * @flow
  */
 
-// Adapted from: https://github.com/facebookarchive/fixed-data-table/blob/master/src/vendor_upstream/dom/normalizeWheel.js
+// Adapted from: https://github.com/facebookarchive/fixed-data-table/blob/main/src/vendor_upstream/dom/normalizeWheel.js
 
 export type NormalizedWheelDelta = {|
   deltaX: number,

packages/react-devtools-shared/src/__tests__/profilingCache-test.js

@@ -672,7 +672,7 @@ describe('ProfilingCache', () => {
 
     const About = () => <div>About</div>;
 
-    // Mimics https://github.com/ReactTraining/react-router/blob/master/packages/react-router/modules/Router.js
+    // Mimics https://github.com/ReactTraining/react-router/blob/main/packages/react-router/modules/Router.js
     function Router({children}) {
       const [path, setPath] = React.useState('/');
       return (
@@ -682,7 +682,7 @@ describe('ProfilingCache', () => {
       );
     }
 
-    // Mimics https://github.com/ReactTraining/react-router/blob/master/packages/react-router/modules/Switch.js
+    // Mimics https://github.com/ReactTraining/react-router/blob/main/packages/react-router/modules/Switch.js
     function Switch({children}) {
       return (
         <RouterContext.Consumer>
@@ -699,14 +699,14 @@ describe('ProfilingCache', () => {
       );
     }
 
-    // Mimics https://github.com/ReactTraining/react-router/blob/master/packages/react-router/modules/Route.js
+    // Mimics https://github.com/ReactTraining/react-router/blob/main/packages/react-router/modules/Route.js
     function Route({children, path}) {
       return null;
     }
 
     const linkRef = React.createRef();
 
-    // Mimics https://github.com/ReactTraining/react-router/blob/master/packages/react-router-dom/modules/Link.js
+    // Mimics https://github.com/ReactTraining/react-router/blob/main/packages/react-router-dom/modules/Link.js
     function Link({children, path}) {
       return (
         <RouterContext.Consumer>

packages/react-devtools-shared/src/backend/renderer.js

@@ -2633,7 +2633,7 @@ export function attach(
   const UNMOUNTED = 3;
 
   // This function is copied from React and should be kept in sync:
-  // https://github.com/facebook/react/blob/master/packages/react-reconciler/src/ReactFiberTreeReflection.js
+  // https://github.com/facebook/react/blob/main/packages/react-reconciler/src/ReactFiberTreeReflection.js
   function isFiberMountedImpl(fiber: Fiber): number {
     let node = fiber;
     let prevNode = null;
@@ -2689,7 +2689,7 @@ export function attach(
   }
 
   // This function is copied from React and should be kept in sync:
-  // https://github.com/facebook/react/blob/master/packages/react-reconciler/src/ReactFiberTreeReflection.js
+  // https://github.com/facebook/react/blob/main/packages/react-reconciler/src/ReactFiberTreeReflection.js
   // It would be nice if we updated React to inject this function directly (vs just indirectly via findDOMNode).
   // BEGIN copied code
   function findCurrentFiberUsingSlowPathById(id: number): Fiber | null {

packages/react-devtools-shared/src/constants.js

@@ -44,7 +44,7 @@ export const LOCAL_STORAGE_TRACE_UPDATES_ENABLED_KEY =
 export const PROFILER_EXPORT_VERSION = 5;
 
 export const CHANGE_LOG_URL =
-  'https://github.com/facebook/react/blob/master/packages/react-devtools/CHANGELOG.md';
+  'https://github.com/facebook/react/blob/main/packages/react-devtools/CHANGELOG.md';
 
 export const UNSUPPORTED_VERSION_URL =
   'https://reactjs.org/blog/2019/08/15/new-react-devtools.html#how-do-i-get-the-old-version-back';

packages/react-devtools-shared/src/devtools/cache.js

@@ -15,7 +15,7 @@ import {createContext} from 'react';
 // TODO (cache) Remove this cache; it is outdated and will not work with newer APIs like startTransition.
 
 // Cache implementation was forked from the React repo:
-// https://github.com/facebook/react/blob/master/packages/react-cache/src/ReactCache.js
+// https://github.com/facebook/react/blob/main/packages/react-cache/src/ReactCache.js
 //
 // This cache is simpler than react-cache in that:
 // 1. Individual items don't need to be invalidated.

packages/react-devtools-shell/README.md

@@ -2,7 +2,7 @@ Harness for testing local changes to the `react-devtools-inline` and `react-devt
 
 ## Development
 
-This target should be run in parallel with the `react-devtools-inline` package. The first step then is to run that target following the instructions in the [`react-devtools-inline` README](https://github.com/facebook/react/blob/master/packages/react-devtools-inline/README.md).
+This target should be run in parallel with the `react-devtools-inline` package. The first step then is to run that target following the instructions in the [`react-devtools-inline` README](https://github.com/facebook/react/blob/main/packages/react-devtools-inline/README.md).
 
 The test harness can then be run as follows:
 ```sh

packages/react-devtools/CHANGELOG.md

@@ -2,7 +2,7 @@
 
 <details>
   <summary>
-    Changes that have landed in master but are not yet released.
+    Changes that have landed in main but are not yet released.
     Click to see more.
   </summary>
 
@@ -380,7 +380,7 @@ New keys can be added to object props/state/hooks now. Existing keys can be rena
 #### Improved performance
 The legacy DevTools extension used to add significant performance overhead, making it unusable for some larger React applications. That overhead has been effectively eliminated in version 4.
 
-[Learn more](https://github.com/facebook/react/blob/master/packages/react-devtools/OVERVIEW.md) about the performance optimizations that made this possible.
+[Learn more](https://github.com/facebook/react/blob/main/packages/react-devtools/OVERVIEW.md) about the performance optimizations that made this possible.
 
 #### Component stacks
 
@@ -406,7 +406,7 @@ Filter preferences are remembered between sessions.
 
 #### No more inline props
 
-Components in the tree no longer show inline props. This was done to [make DevTools faster](https://github.com/facebook/react/blob/master/packages/react-devtools/OVERVIEW.md) and to make it easier to browse larger component trees.
+Components in the tree no longer show inline props. This was done to [make DevTools faster](https://github.com/facebook/react/blob/main/packages/react-devtools/OVERVIEW.md) and to make it easier to browse larger component trees.
 
 You can view a component's props, state, and hooks by selecting it:
 

packages/react-devtools/OVERVIEW.md

@@ -259,7 +259,7 @@ Even when dealing with a single component, serializing deeply nested properties
 
 Hooks present a unique challenge for the DevTools because of the concept of _custom_ hooks. (A custom hook is essentially any function that calls at least one of the built-in hooks. By convention custom hooks also have names that begin with "use".)
 
-So how does DevTools identify custom functions called from within third party components? It does this by temporarily overriding React's built-in hooks and shallow rendering the component in question. Whenever one of the (overridden) built-in hooks are called, it parses the call stack to spot potential custom hooks (functions between the component itself and the built-in hook). This approach enables it to build a tree structure describing all of the calls to both the built-in _and_ custom hooks, along with the values passed to those hooks. (If you're interested in learning more about this, [here is the source code](https://github.com/facebook/react/blob/master/packages/react-debug-tools/src/ReactDebugHooks.js).)
+So how does DevTools identify custom functions called from within third party components? It does this by temporarily overriding React's built-in hooks and shallow rendering the component in question. Whenever one of the (overridden) built-in hooks are called, it parses the call stack to spot potential custom hooks (functions between the component itself and the built-in hook). This approach enables it to build a tree structure describing all of the calls to both the built-in _and_ custom hooks, along with the values passed to those hooks. (If you're interested in learning more about this, [here is the source code](https://github.com/facebook/react/blob/main/packages/react-debug-tools/src/ReactDebugHooks.js).)
 
 > **Note**: DevTools obtains hooks info by re-rendering a component.
 > Breakpoints will be invoked during this additional (shallow) render,

packages/react-devtools/README.md

@@ -105,7 +105,7 @@ Or you could develop with a local HTTP server [like `serve`](https://www.npmjs.c
 
 **If your app is inside of CodePen**, make sure you are registered. Then press Fork (if it's not your pen), and then choose Change View > Debug. The Debug view is inspectable with DevTools because it doesn't use an iframe.
 
-**If your app is inside an iframe, a Chrome extension, React Native, or in another unusual environment**, try [the standalone version instead](https://github.com/facebook/react/tree/master/packages/react-devtools). Chrome apps are currently not inspectable.
+**If your app is inside an iframe, a Chrome extension, React Native, or in another unusual environment**, try [the standalone version instead](https://github.com/facebook/react/tree/main/packages/react-devtools). Chrome apps are currently not inspectable.
 
 **If you still have issues** please [report them](https://github.com/facebook/react/issues/new?labels=Component:%20Developer%20Tools). Don't forget to specify your OS, browser version, extension version, and the exact instructions to reproduce the issue with a screenshot.
 

packages/react-reconciler/README.md

@@ -51,15 +51,15 @@ const HostConfig = {
 * **[Building a simple custom renderer to DOM](https://medium.com/@agent_hunt/hello-world-custom-react-renderer-9a95b7cd04bc)**
 * **[Building a simple custom renderer to native](https://medium.com/@agent_hunt/introduction-to-react-native-renderers-aka-react-native-is-the-java-and-react-native-renderers-are-828a0022f433)**
 
-The full list of supported methods [can be found here](https://github.com/facebook/react/blob/master/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js). For their signatures, we recommend looking at specific examples below.
+The full list of supported methods [can be found here](https://github.com/facebook/react/blob/main/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js). For their signatures, we recommend looking at specific examples below.
 
 The React repository includes several renderers. Each of them has its own host config.
 
 The examples in the React repository are declared a bit differently than a third-party renderer would be. In particular, the `HostConfig` object mentioned above is never explicitly declared, and instead is a *module* in our code. However, its exports correspond directly to properties on a `HostConfig` object you'd need to declare in your code:
 
-* [React ART](https://github.com/facebook/react/blob/master/packages/react-art/src/ReactART.js) and its [host config](https://github.com/facebook/react/blob/master/packages/react-art/src/ReactARTHostConfig.js)
+* [React ART](https://github.com/facebook/react/blob/main/packages/react-art/src/ReactART.js) and its [host config](https://github.com/facebook/react/blob/main/packages/react-art/src/ReactARTHostConfig.js)
-* [React DOM](https://github.com/facebook/react/blob/master/packages/react-dom/src/client/ReactDOM.js) and its [host config](https://github.com/facebook/react/blob/master/packages/react-dom/src/client/ReactDOMHostConfig.js)
+* [React DOM](https://github.com/facebook/react/blob/main/packages/react-dom/src/client/ReactDOM.js) and its [host config](https://github.com/facebook/react/blob/main/packages/react-dom/src/client/ReactDOMHostConfig.js)
-* [React Native](https://github.com/facebook/react/blob/master/packages/react-native-renderer/src/ReactNativeRenderer.js) and its [host config](https://github.com/facebook/react/blob/master/packages/react-native-renderer/src/ReactNativeHostConfig.js)
+* [React Native](https://github.com/facebook/react/blob/main/packages/react-native-renderer/src/ReactNativeRenderer.js) and its [host config](https://github.com/facebook/react/blob/main/packages/react-native-renderer/src/ReactNativeHostConfig.js)
 
 If these links break please file an issue and we’ll fix them. They intentionally link to the latest versions since the API is still evolving. If you have more questions please file an issue and we’ll try to help!
 
@@ -332,10 +332,10 @@ This method should mutate the `container` root node and remove all children from
 
 ### Persistence Methods
 
-If you use the persistent mode instead of the mutation mode, you would still need the "Core Methods". However, instead of the Mutation Methods above you will implement a different set of methods that performs cloning nodes and replacing them at the root level. You can find a list of them in the "Persistence" section [listed in this file](https://github.com/facebook/react/blob/master/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js). File an issue if you need help.
+If you use the persistent mode instead of the mutation mode, you would still need the "Core Methods". However, instead of the Mutation Methods above you will implement a different set of methods that performs cloning nodes and replacing them at the root level. You can find a list of them in the "Persistence" section [listed in this file](https://github.com/facebook/react/blob/main/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js). File an issue if you need help.
 
 ### Hydration Methods
 
 You can optionally implement hydration to "attach" to the existing tree during the initial render instead of creating it from scratch. For example, the DOM renderer uses this to attach to an HTML markup.
 
-To support hydration, you need to declare `supportsHydration: true` and then implement the methods in the "Hydration" section [listed in this file](https://github.com/facebook/react/blob/master/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js). File an issue if you need help.
+To support hydration, you need to declare `supportsHydration: true` and then implement the methods in the "Hydration" section [listed in this file](https://github.com/facebook/react/blob/main/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js). File an issue if you need help.

packages/react/index.js

@@ -7,7 +7,7 @@
  * @flow
  */
 
-// Keep in sync with https://github.com/facebook/flow/blob/master/lib/react.js
+// Keep in sync with https://github.com/facebook/flow/blob/main/lib/react.js
 export type StatelessFunctionalComponent<
   P,
 > = React$StatelessFunctionalComponent<P>;

packages/use-subscription/README.md

@@ -8,7 +8,7 @@ This utility can be used for subscriptions to a single value that are typically
 
 Most other cases have **better long-term solutions**:
 * Redux/Flux stores should use the [context API](https://reactjs.org/docs/context.html) instead.
-* I/O subscriptions (e.g. notifications) that update infrequently should use a mechanism like [`react-cache`](https://github.com/facebook/react/blob/master/packages/react-cache/README.md) instead.
+* I/O subscriptions (e.g. notifications) that update infrequently should use a mechanism like [`react-cache`](https://github.com/facebook/react/blob/main/packages/react-cache/README.md) instead.
 * Complex libraries like Relay/Apollo should manage subscriptions manually with the same techniques which this library uses under the hood (as referenced [here](https://gist.github.com/bvaughn/d569177d70b50b58bff69c3c4a5353f3)) in a way that is most optimized for their library usage.
 
 ## Limitations in concurrent mode

scripts/bench/README.md

@@ -27,8 +27,8 @@ yarn start --local
 # will only build and run remote merge base repo against benchmarks (no local values will be shown)
 yarn start --remote
 
-# will only build and run remote master repo against benchmarks
+# will only build and run remote main repo against benchmarks
-yarn start --remote=master
+yarn start --remote=main
 
 # same as "yarn start"
 yarn start --remote --local

scripts/bench/build.js

@@ -55,7 +55,7 @@ async function getMergeBaseFromLocalGitRepo(localRepo) {
   return await Git.Merge.base(
     repo,
     await repo.getHeadCommit(),
-    await repo.getBranchCommit('master')
+    await repo.getBranchCommit('main')
   );
 }
 
@@ -82,15 +82,15 @@ async function buildBenchmarkBundlesFromGitRepo(
       // if not, clone the repo to remote-repo folder
       repo = await Git.Clone(url, remoteRepoDir);
     }
-    let commit = await repo.getBranchCommit('master');
+    let commit = await repo.getBranchCommit('main');
     // reset hard to this remote head
     await Git.Reset.reset(repo, commit, Git.Reset.TYPE.HARD);
-    // then we checkout the latest master head
+    // then we checkout the latest main head
-    await repo.checkoutBranch('master');
+    await repo.checkoutBranch('main');
     // make sure we pull in the latest changes
-    await repo.mergeBranches('master', 'origin/master');
+    await repo.mergeBranches('main', 'origin/main');
     // then we check if we need to move the HEAD to the merge base
-    if (commitId && commitId !== 'master') {
+    if (commitId && commitId !== 'main') {
       // as the commitId probably came from our local repo
       // we use it to lookup the right commit in our remote repo
       commit = await Git.Commit.lookup(repo, commitId);

scripts/bench/runner.js

@@ -61,7 +61,7 @@ async function runBenchmarks(reactPath) {
 }
 
 // get the performance benchmark results
-// from remote master (default React repo)
+// from remote main (default React repo)
 async function benchmarkRemoteMaster() {
   console.log(chalk.gray(`- Building React bundles...`));
   let commit = argv.remote;

scripts/error-codes/README.md

@@ -2,14 +2,14 @@ The error code system substitutes React's error messages with error IDs to
 provide a better debugging support in production. Check out the blog post
 [here](https://reactjs.org/blog/2016/07/11/introducing-reacts-error-code-system.html).
 
-- [`codes.json`](https://github.com/facebook/react/blob/master/scripts/error-codes/codes.json)
+- [`codes.json`](https://github.com/facebook/react/blob/main/scripts/error-codes/codes.json)
   contains the mapping from IDs to error messages. This file is generated by the
   Gulp plugin and is used by both the Babel plugin and the error decoder page in
   our documentation. This file is append-only, which means an existing code in
   the file will never be changed/removed.
-- [`extract-errors.js`](https://github.com/facebook/react/blob/master/scripts/error-codes/extract-errors.js)
+- [`extract-errors.js`](https://github.com/facebook/react/blob/main/scripts/error-codes/extract-errors.js)
   is an node script that traverses our codebase and updates `codes.json`. You
   can test it by running `yarn extract-errors`.
-- [`transform-error-messages`](https://github.com/facebook/react/blob/master/scripts/error-codes/transform-error-messages.js)
+- [`transform-error-messages`](https://github.com/facebook/react/blob/main/scripts/error-codes/transform-error-messages.js)
   is a Babel pass that rewrites error messages to IDs for a production
   (minified) build.

scripts/error-codes/extract-errors.js

@@ -18,7 +18,7 @@ const babylonOptions = {
   // As a parser, babylon has its own options and we can't directly
   // import/require a babel preset. It should be kept **the same** as
   // the `babel-plugin-syntax-*` ones specified in
-  // https://github.com/facebook/fbjs/blob/master/packages/babel-preset-fbjs/configure.js
+  // https://github.com/facebook/fbjs/blob/main/packages/babel-preset-fbjs/configure.js
   plugins: [
     'classProperties',
     'flow',

scripts/merge-fork/README.md

@@ -51,7 +51,7 @@ By default, the changes are compared to HEAD. You can use `--base-ref` to compar
 
 ```sh
 yarn merge-fork \
-  --base-ref=$(git merge-base HEAD origin/master)
+  --base-ref=$(git merge-base HEAD origin/main)
   --base-dir=packages/react-reconciler/src \
   ReactFiberWorkLoop
 ```

scripts/print-warnings/print-warnings.js

@@ -19,7 +19,7 @@ const parserOptions = {
   // babelParser has its own options and we can't directly
   // import/require a babel preset. It should be kept **the same** as
   // the `babel-plugin-syntax-*` ones specified in
-  // https://github.com/facebook/fbjs/blob/master/packages/babel-preset-fbjs/configure.js
+  // https://github.com/facebook/fbjs/blob/main/packages/babel-preset-fbjs/configure.js
   plugins: [
     'classProperties',
     'flow',

scripts/release/README.md

@@ -50,7 +50,7 @@ The sections below include meaningful `--tags` in the instructions. However, kee
 "Next" builds are meant to be lightweight and published often. In most cases, they can be published using artifacts built by Circle CI.
 
 To prepare a build for a particular commit:
-1. Choose a commit from [the commit log](https://github.com/facebook/react/commits/master).
+1. Choose a commit from [the commit log](https://github.com/facebook/react/commits/main).
 2. Copy the SHA (by clicking the 📋 button)
 5. Run the [`prepare-release-from-ci`](#prepare-release-from-ci) script with the SHA <sup>1</sup> you found:
 ```sh
@@ -115,7 +115,7 @@ Begin by creating a branch from the previous git tag<sup>1</sup>:
 git checkout -b 16.8.3 v16.8.2
 ```
 
-Next cherry pick any changes from master that you want to include in the release:
+Next cherry pick any changes from main that you want to include in the release:
 
 ```sh
 git cherry-pick <commit-hash>

scripts/release/prepare-release-from-ci.js

@@ -12,7 +12,7 @@ const testPackagingFixture = require('./shared-commands/test-packaging-fixture')
 
 const run = async () => {
   try {
-    addDefaultParamValue(null, '--commit', 'master');
+    addDefaultParamValue(null, '--commit', 'main');
 
     const params = await parseParams();
     params.cwd = join(__dirname, '..', '..');

scripts/release/prepare-release-from-npm-commands/guess-stable-version-numbers.js

@@ -25,9 +25,9 @@ const run = async ({cwd, packages, skipPackages}, versionsMap) => {
 
         // Guess the next version by incrementing patch.
         // The script will confirm this later.
-        // By default, new releases from masters should increment the minor version number,
+        // By default, new releases from mains should increment the minor version number,
         // and patch releases should be done from branches.
-        if (branch === 'master') {
+        if (branch === 'main') {
           versionsMap.set(packageName, `${major}.${minor + 1}.0`);
         } else {
           versionsMap.set(packageName, `${major}.${minor}.${patch + 1}`);

scripts/release/publish-using-ci-workflow.js

@@ -78,7 +78,7 @@ async function pollUntilWorkflowFinishes(workflowID) {
 
 async function main() {
   const headCommitResponse = await fetch(
-    'https://api.github.com/repos/facebook/react/commits/master'
+    'https://api.github.com/repos/facebook/react/commits/main'
   );
   const headCommitJSON = await headCommitResponse.json();
   const headCommitSha = headCommitJSON.sha;

scripts/shared/listChangedFiles.js

@@ -26,7 +26,7 @@ const execGitCmd = args =>
     .split('\n');
 
 const listChangedFiles = () => {
-  const mergeBase = execGitCmd(['merge-base', 'HEAD', 'master']);
+  const mergeBase = execGitCmd(['merge-base', 'HEAD', 'main']);
   return new Set([
     ...execGitCmd(['diff', '--name-only', '--diff-filter=ACMRTUB', mergeBase]),
     ...execGitCmd(['ls-files', '--others', '--exclude-standard']),