Reactの内部実装を見る（1. useState編）

if (typeof initialState === 'function') {
 initialState = initialState();
}

// 以下1行は
hook.memoizedState = hook.baseState = initialState;
// 以下2行と同じ
hook.memoizedState = initialState;
hook.baseState = initialState;

const HooksDispatcherOnMount: Dispatcher = {
    readContext,
    
    useCallback: mountCallback,
    useContext: readContext,
    useEffect: mountEffect,
    useImperativeHandle: mountImperativeHandle,
    useLayoutEffect: mountLayoutEffect,
    useInsertionEffect: mountInsertionEffect,
    useMemo: mountMemo,
    useReducer: mountReducer,
    useRef: mountRef,
    useState: mountState,
    useDebugValue: mountDebugValue,
    useDeferredValue: mountDeferredValue,
    useTransition: mountTransition,
    useMutableSource: mountMutableSource,
    useSyncExternalStore: mountSyncExternalStore,
    useId: mountId,
    
    unstable_isNewReconciler: enableNewReconciler,
};

const queue: UpdateQueue<S, BasicStateAction<S>> = {
    pending: null,
    interleaved: null,
    lanes: NoLanes,
    dispatch: null,
    lastRenderedReducer: basicStateReducer,
    lastRenderedState: (initialState: any),
};

const dispatch: Dispatch<
    BasicStateAction<S>,
> = (queue.dispatch = (dispatchSetState.bind(
    null,
    currentlyRenderingFiber,
    queue,
): any));

git clone https://github.com/facebook/react.git

react\packages\react\src\ReactHooks.js

function resolveDispatcher() {
  const dispatcher = ReactSharedInternals.H;
  if (__DEV__) {
    if (dispatcher === null) {
      console.error(
        'Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for' +
          ' one of the following reasons:\n' +
          '1. You might have mismatching versions of React and the renderer (such as React DOM)\n' +
          '2. You might be breaking the Rules of Hooks\n' +
          '3. You might have more than one copy of React in the same app\n' +
          'See https://react.dev/link/invalid-hook-call for tips about how to debug and fix this problem.',
      );
    }
  }
  // Will result in a null access error if accessed outside render phase. We
  // intentionally don't throw our own error because this is in a hot path.
  // Also helps ensure this is inlined.
  return ((dispatcher: any): Dispatcher);
}

const dispatcher = ReactCurrentDispatcher.current;  // これが
const dispatcher = ReactSharedInternals.H;  // これになってる

import ReactSharedInternals from 'shared/ReactSharedInternals';

react\packages\react\src\ReactHooks.js

react\packages\shared\ReactSharedInternals.js

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import * as React from 'react';

const ReactSharedInternals =
  React.__CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE;

export default ReactSharedInternals;

C:\Users\ユーザー名\node_modules\react\index.js

'use strict';

if (process.env.NODE_ENV === 'production') {
  module.exports = require('./cjs/react.production.min.js');
} else {
  module.exports = require('./cjs/react.development.js');
}

/**
 * @license React
 * react.production.min.js
 *
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
'use strict';var l=Symbol.for("react.element"),n=Symbol.for("react.portal"),p=Symbol.for("react.fragment"),q=Symbol.for("react.strict_mode"),r=Symbol.for("react.profiler"),t=Symbol.for("react.provider"),u=Symbol.for("react.context"),v=Symbol.for("react.forward_ref"),w=Symbol.for("react.suspense"),x=Symbol.for("react.memo"),y=Symbol.for("react.lazy"),z=Symbol.iterator;function A(a){if(null===a||"object"!==typeof a)return null;a=z&&a[z]||a["@@iterator"];return"function"===typeof a?a:null}
var B={isMounted:function(){return!1},enqueueForceUpdate:function(){},enqueueReplaceState:function(){},enqueueSetState:function(){}},C=Object.assign,D={};function E(a,b,e){this.props=a;this.context=b;this.refs=D;this.updater=e||B}E.prototype.isReactComponent={};
E.prototype.setState=function(a,b){if("object"!==typeof a&&"function"!==typeof a&&null!=a)throw Error("setState(...): takes an object of state variables to update or a function which returns an object of state variables.");this.updater.enqueueSetState(this,a,b,"setState")};E.prototype.forceUpdate=function(a){this.updater.enqueueForceUpdate(this,a,"forceUpdate")};function F(){}F.prototype=E.prototype;function G(a,b,e){this.props=a;this.context=b;this.refs=D;this.updater=e||B}var H=G.prototype=new F;
H.constructor=G;C(H,E.prototype);H.isPureReactComponent=!0;var I=Array.isArray,J=Object.prototype.hasOwnProperty,K={current:null},L={key:!0,ref:!0,__self:!0,__source:!0};
function M(a,b,e){var d,c={},k=null,h=null;if(null!=b)for(d in void 0!==b.ref&&(h=b.ref),void 0!==b.key&&(k=""+b.key),b)J.call(b,d)&&!L.hasOwnProperty(d)&&(c[d]=b[d]);var g=arguments.length-2;if(1===g)c.children=e;else if(1<g){for(var f=Array(g),m=0;m<g;m++)f[m]=arguments[m+2];c.children=f}if(a&&a.defaultProps)for(d in g=a.defaultProps,g)void 0===c[d]&&(c[d]=g[d]);return{$$typeof:l,type:a,key:k,ref:h,props:c,_owner:K.current}}
function N(a,b){return{$$typeof:l,type:a.type,key:b,ref:a.ref,props:a.props,_owner:a._owner}}function O(a){return"object"===typeof a&&null!==a&&a.$$typeof===l}function escape(a){var b={"=":"=0",":":"=2"};return"$"+a.replace(/[=:]/g,function(a){return b[a]})}var P=/\/+/g;function Q(a,b){return"object"===typeof a&&null!==a&&null!=a.key?escape(""+a.key):b.toString(36)}
function R(a,b,e,d,c){var k=typeof a;if("undefined"===k||"boolean"===k)a=null;var h=!1;if(null===a)h=!0;else switch(k){case "string":case "number":h=!0;break;case "object":switch(a.$$typeof){case l:case n:h=!0}}if(h)return h=a,c=c(h),a=""===d?"."+Q(h,0):d,I(c)?(e="",null!=a&&(e=a.replace(P,"$&/")+"/"),R(c,b,e,"",function(a){return a})):null!=c&&(O(c)&&(c=N(c,e+(!c.key||h&&h.key===c.key?"":(""+c.key).replace(P,"$&/")+"/")+a)),b.push(c)),1;h=0;d=""===d?".":d+":";if(I(a))for(var g=0;g<a.length;g++){k=
a[g];var f=d+Q(k,g);h+=R(k,b,e,f,c)}else if(f=A(a),"function"===typeof f)for(a=f.call(a),g=0;!(k=a.next()).done;)k=k.value,f=d+Q(k,g++),h+=R(k,b,e,f,c);else if("object"===k)throw b=String(a),Error("Objects are not valid as a React child (found: "+("[object Object]"===b?"object with keys {"+Object.keys(a).join(", ")+"}":b)+"). If you meant to render a collection of children, use an array instead.");return h}
function S(a,b,e){if(null==a)return a;var d=[],c=0;R(a,d,"","",function(a){return b.call(e,a,c++)});return d}function T(a){if(-1===a._status){var b=a._result;b=b();b.then(function(b){if(0===a._status||-1===a._status)a._status=1,a._result=b},function(b){if(0===a._status||-1===a._status)a._status=2,a._result=b});-1===a._status&&(a._status=0,a._result=b)}if(1===a._status)return a._result.default;throw a._result;}
var U={current:null},V={transition:null},W={ReactCurrentDispatcher:U,ReactCurrentBatchConfig:V,ReactCurrentOwner:K};exports.Children={map:S,forEach:function(a,b,e){S(a,function(){b.apply(this,arguments)},e)},count:function(a){var b=0;S(a,function(){b++});return b},toArray:function(a){return S(a,function(a){return a})||[]},only:function(a){if(!O(a))throw Error("React.Children.only expected to receive a single React element child.");return a}};exports.Component=E;exports.Fragment=p;
exports.Profiler=r;exports.PureComponent=G;exports.StrictMode=q;exports.Suspense=w;exports.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED=W;
exports.cloneElement=function(a,b,e){if(null===a||void 0===a)throw Error("React.cloneElement(...): The argument must be a React element, but you passed "+a+".");var d=C({},a.props),c=a.key,k=a.ref,h=a._owner;if(null!=b){void 0!==b.ref&&(k=b.ref,h=K.current);void 0!==b.key&&(c=""+b.key);if(a.type&&a.type.defaultProps)var g=a.type.defaultProps;for(f in b)J.call(b,f)&&!L.hasOwnProperty(f)&&(d[f]=void 0===b[f]&&void 0!==g?g[f]:b[f])}var f=arguments.length-2;if(1===f)d.children=e;else if(1<f){g=Array(f);
for(var m=0;m<f;m++)g[m]=arguments[m+2];d.children=g}return{$$typeof:l,type:a.type,key:c,ref:k,props:d,_owner:h}};exports.createContext=function(a){a={$$typeof:u,_currentValue:a,_currentValue2:a,_threadCount:0,Provider:null,Consumer:null,_defaultValue:null,_globalName:null};a.Provider={$$typeof:t,_context:a};return a.Consumer=a};exports.createElement=M;exports.createFactory=function(a){var b=M.bind(null,a);b.type=a;return b};exports.createRef=function(){return{current:null}};
exports.forwardRef=function(a){return{$$typeof:v,render:a}};exports.isValidElement=O;exports.lazy=function(a){return{$$typeof:y,_payload:{_status:-1,_result:a},_init:T}};exports.memo=function(a,b){return{$$typeof:x,type:a,compare:void 0===b?null:b}};exports.startTransition=function(a){var b=V.transition;V.transition={};try{a()}finally{V.transition=b}};exports.unstable_act=function(){throw Error("act(...) is not supported in production builds of React.");};
exports.useCallback=function(a,b){return U.current.useCallback(a,b)};exports.useContext=function(a){return U.current.useContext(a)};exports.useDebugValue=function(){};exports.useDeferredValue=function(a){return U.current.useDeferredValue(a)};exports.useEffect=function(a,b){return U.current.useEffect(a,b)};exports.useId=function(){return U.current.useId()};exports.useImperativeHandle=function(a,b,e){return U.current.useImperativeHandle(a,b,e)};
exports.useInsertionEffect=function(a,b){return U.current.useInsertionEffect(a,b)};exports.useLayoutEffect=function(a,b){return U.current.useLayoutEffect(a,b)};exports.useMemo=function(a,b){return U.current.useMemo(a,b)};exports.useReducer=function(a,b,e){return U.current.useReducer(a,b,e)};exports.useRef=function(a){return U.current.useRef(a)};exports.useState=function(a){return U.current.useState(a)};exports.useSyncExternalStore=function(a,b,e){return U.current.useSyncExternalStore(a,b,e)};
exports.useTransition=function(){return U.current.useTransition()};exports.version="18.2.0";

function useState(initialState) {
  var dispatcher = resolveDispatcher();
  return dispatcher.useState(initialState);
function useEffect(create, deps) {
  var dispatcher = resolveDispatcher();
  return dispatcher.useEffect(create, deps);
}

// ...

exports.Children = Children;
exports.Component = Component;
exports.Fragment = REACT_FRAGMENT_TYPE;
exports.Profiler = REACT_PROFILER_TYPE;
exports.PureComponent = PureComponent;
exports.StrictMode = REACT_STRICT_MODE_TYPE;
exports.Suspense = REACT_SUSPENSE_TYPE;
exports.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED = ReactSharedInternals;
exports.cloneElement = cloneElement$1;
exports.createContext = createContext;
exports.createElement = createElement$1;
exports.createFactory = createFactory;
exports.createRef = createRef;
exports.forwardRef = forwardRef;
exports.isValidElement = isValidElement;
exports.lazy = lazy;
exports.memo = memo;
exports.startTransition = startTransition;
exports.unstable_act = act;
exports.useCallback = useCallback;
exports.useContext = useContext;
exports.useDebugValue = useDebugValue;
exports.useDeferredValue = useDeferredValue;
exports.useEffect = useEffect;
exports.useId = useId;
exports.useImperativeHandle = useImperativeHandle;
exports.useInsertionEffect = useInsertionEffect;
exports.useLayoutEffect = useLayoutEffect;
exports.useMemo = useMemo;
exports.useReducer = useReducer;
exports.useRef = useRef;
exports.useState = useState;
exports.useSyncExternalStore = useSyncExternalStore;
exports.useTransition = useTransition;
exports.version = ReactVersion;

import React from "react";
console.log(React);

"dependencies": {
    "react": "^18.3.1",
},

npm create vite@latest

import React from "react";
console.log(React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED);

ReactDebugCurrentFrame.getStackAddendum = function() {
    var stack = "";
    if (currentExtraStackFrame) {
      stack += currentExtraStackFrame;
    }
    var impl = ReactDebugCurrentFrame.getCurrentStack;
    if (impl) {
      stack += impl() || "";
    }
    return stack;
};

ReactDebugCurrentFrame.setExtraStackFrame = function(stack) {
    {
    currentExtraStackFrame = stack;
    }
};

function resolveDispatcher() {
  const dispatcher = ReactSharedInternals.H;
  if (__DEV__) {
    if (dispatcher === null) {
      console.error(
        'Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for' +
          ' one of the following reasons:\n' +
          '1. You might have mismatching versions of React and the renderer (such as React DOM)\n' +
          '2. You might be breaking the Rules of Hooks\n' +
          '3. You might have more than one copy of React in the same app\n' +
          'See https://react.dev/link/invalid-hook-call for tips about how to debug and fix this problem.',
      );
    }
  }
  // Will result in a null access error if accessed outside render phase. We
  // intentionally don't throw our own error because this is in a hot path.
  // Also helps ensure this is inlined.
  return ((dispatcher: any): Dispatcher);
}

yarn install
yarn build
yarn test

Process spawn error. Is java in the path?
spawn java ENOENT

"scripts": {
    "build": "node ./scripts/rollup/build-all-release-channels.js",
    "build-for-devtools": "cross-env RELEASE_CHANNEL=experimental yarn build react/index,react/jsx,react/compiler-runtime,react-dom/index,react-dom/client,react-dom/unstable_testing,react-dom/test-utils,react-is,react-debug-tools,scheduler,react-test-renderer,react-refresh,react-art --type=NODE",
    "build-for-devtools-dev": "yarn build-for-devtools --type=NODE_DEV",
    "build-for-devtools-prod": "yarn build-for-devtools --type=NODE_PROD",
    "build-for-flight-dev": "cross-env RELEASE_CHANNEL=experimental node ./scripts/rollup/build.js react/index,react/jsx,react.react-server,react-dom/index,react-dom/client,react-dom/server,react-dom.react-server,react-dom-server.node,react-dom-server-legacy.node,scheduler,react-server-dom-webpack/ --type=NODE_DEV,ESM_PROD,NODE_ES2015 && mv ./build/node_modules ./build/oss-experimental",
}

yarn run flow dom-node

errno: -4071,
code: 'EINVAL',
syscall: 'spawn'

"scripts": {
    "flow": "node ./scripts/tasks/flow.js",
}

node ./scripts/tasks/flow.js dom-node

code: 'EINVAL',

syscall: 'spawn'

'use strict';

process.on('unhandledRejection', err => {
  throw err;
});

const chalk = require('chalk');
const runFlow = require('../flow/runFlow');
const inlinedHostConfigs = require('../shared/inlinedHostConfigs');

// This script is using `flow status` for a quick check with a server.
// Use it for local development.

const primaryRenderer = inlinedHostConfigs.find(
  info => info.isFlowTyped && info.shortName === process.argv[2]
);
if (!primaryRenderer) {
  console.log(
    'The ' +
      chalk.red('yarn flow') +
      ' command now requires you to pick a primary renderer:'
  );
  console.log();
  inlinedHostConfigs.forEach(rendererInfo => {
    if (rendererInfo.isFlowTyped) {
      console.log('  * ' + chalk.cyan('yarn flow ' + rendererInfo.shortName));
    }
  });
  console.log();
  console.log(
    'If you are not sure, run ' + chalk.green('yarn flow dom-node') + '.'
  );
  console.log(
    'This will still typecheck non-DOM packages, although less precisely.'
  );
  console.log();
  console.log('Note that checks for all renderers will run on CI.');
  console.log(
    'You can also do this locally with ' +
      chalk.cyan('yarn flow-ci') +
      ' but it will be slow.'
  );
  console.log();
  process.exit(1);
}

runFlow(primaryRenderer.shortName, ['status']);

if (!primaryRenderer) {
  console.log(
    'The ' +
      chalk.red('yarn flow') +
      ' command now requires you to pick a primary renderer:'
  );
  // ...

const primaryRenderer = inlinedHostConfigs.find(
  info => info.isFlowTyped && info.shortName === process.argv[2]
);

process.exit(1);

runFlow(primaryRenderer.shortName, ['status']);

'use strict';

const chalk = require('chalk');
const {spawn} = require('child_process');
const fs = require('fs');

// TODO: This generates all the renderer configs at once. Originally this was
// to allow the possibility of running multiple Flow processes in parallel, but
// that never happened. If we did, we'd probably do this in CI, anyway, and run
// on multiple machines. So instead we could remove this intermediate step and
// generate only the config for the specified renderer.
require('./createFlowConfigs');

async function runFlow(renderer, args) {
  return new Promise(resolve => {
    let cmd = __dirname + '/../../node_modules/.bin/flow';
    if (process.platform === 'win32') {
      cmd = cmd.replace(/\//g, '\\') + '.cmd';
    }

    // Copy renderer flowconfig file to the root of the project so that it
    // works with editor integrations. This means that the Flow config used by
    // the editor will correspond to the last renderer you checked.
    const srcPath =
      process.cwd() + '/scripts/flow/' + renderer + '/.flowconfig';
    const srcStat = fs.statSync(__dirname + '/config/flowconfig');
    const destPath = './.flowconfig';
    if (fs.existsSync(destPath)) {
      const oldConfig = String(fs.readFileSync(destPath));
      const newConfig = String(fs.readFileSync(srcPath));
      if (oldConfig !== newConfig) {
        // Use the mtime to detect if the file was manually edited. If so,
        // log an error.
        const destStat = fs.statSync(destPath);
        if (destStat.mtimeMs - srcStat.mtimeMs > 1) {
          console.error(
            chalk.red(
              'Detected manual changes to .flowconfig, which is a generated ' +
                'file. These changes have been discarded.\n\n' +
                'To change the Flow config, edit the template in ' +
                'scripts/flow/config/flowconfig. Then run this command again.\n',
            ),
          );
        }
        fs.unlinkSync(destPath);
        fs.copyFileSync(srcPath, destPath);
        // Set the mtime of the copied file to be same as the original file,
        // so that the above check works.
        fs.utimesSync(destPath, srcStat.atime, srcStat.mtime);
      }
    } else {
      fs.copyFileSync(srcPath, destPath);
      fs.utimesSync(destPath, srcStat.atime, srcStat.mtime);
    }

    console.log(
      'Running Flow on the ' + chalk.yellow(renderer) + ' renderer...',
    );

    spawn(cmd, args, {
      // Allow colors to pass through:
      stdio: 'inherit',
    }).on('close', function (code) {
      if (code !== 0) {
        console.error(
          'Flow failed for the ' + chalk.red(renderer) + ' renderer',
        );
        console.log();
        process.exit(code);
      } else {
        console.log(
          'Flow passed for the ' + chalk.green(renderer) + ' renderer',
        );
        resolve();
      }
    });
  });
}

module.exports = runFlow;

console.log(
  'Running Flow on the ' + chalk.yellow(renderer) + ' renderer...',
);

spawn(cmd, args, {
  // Allow colors to pass through:
  stdio: 'inherit',
}).on('close', function (code) {
  if (code !== 0) {
    console.error(
      'Flow failed for the ' + chalk.red(renderer) + ' renderer',
    );
    console.log();
    process.exit(code);
  } else {
    console.log(
      'Flow passed for the ' + chalk.green(renderer) + ' renderer',
    );
    resolve();
  }
});

let cmd = __dirname + '/../../node_modules/.bin/flow';

#!/bin/sh
basedir=$(dirname "$(echo "$0" | sed -e 's,\\,/,g')")

case `uname` in
    *CYGWIN*) basedir=`cygpath -w "$basedir"`;;
esac

if [ -x "$basedir/node" ]; then
  "$basedir/node"  "$basedir/../flow-bin/cli.js" "$@"
  ret=$?
else 
  node  "$basedir/../flow-bin/cli.js" "$@"
  ret=$?
fi
exit $ret

if (process.platform === 'win32') {
  cmd = cmd.replace(/\//g, '\\') + '.cmd';
}

react\scripts\flow/../../node_modules/.bin/flow

react\scripts\flow\..\..\node_modules\.bin\flow.cmd

const srcPath = process.cwd() + '/scripts/flow/' + renderer + '/.flowconfig';

\react

runFlow(primaryRenderer.shortName, ['status']);

const srcPath = process.cwd() + '/scripts/flow/' + renderer + '/.flowconfig';

react/scripts/flow/dom-node/.flowconfig

const srcStat = fs.statSync(__dirname + '/config/flowconfig');

react\scripts\flow

react\scripts\flow/config/flowconfig

[ignore]
.*/scripts/bench/.*
.*/build/.*
.*/fixtures/.*
# Any hidden directory
.*/\..*

# These shims are copied into external projects:
.*/rollup/shims/facebook-www/.*
.*/rollup/shims/react-native/.*

.*/node_modules/fbjs/lib/keyMirrorRecursive.js.flow
.*/node_modules/resolve/test/.*
.*/__mocks__/.*
.*/__tests__/.*

# contains modern flow syntax that requires a Flow upgrade
.*/node_modules/prettier-plugin-hermes-parser/.*

# TODO: noop should get its own inlinedHostConfig entry
.*/packages/react-noop-renderer/.*

%REACT_RENDERER_FLOW_IGNORES%

[libs]
./node_modules/fbjs/flow/lib/dev.js
./scripts/flow/environment.js
./scripts/flow/react-devtools.js
./scripts/flow/react-native-host-hooks.js
./scripts/flow/xplat.js

[lints]
untyped-type-import=error
internal-type=off
deprecated-type=off

[options]
munge_underscores=false
react.custom_jsx_typing=true

# Substituted by createFlowConfig.js:
%REACT_RENDERER_FLOW_OPTIONS%

[version]
%FLOW_VERSION%

const destPath = './.flowconfig';

if (fs.existsSync(destPath)) {

C:\Users\ユーザ名\node_modules\@types\node\fs.d.ts

export function existsSync(path: PathLike): boolean;

export function exists(path: PathLike, callback: (exists: boolean) => void): void;
/** @deprecated */
export namespace exists {
    /**
     * @param path A path to a file or directory. If a URL is provided, it must use the `file:` protocol.
     * URL support is _experimental_.
     */
    function __promisify__(path: PathLike): Promise<boolean>;
}

if (fs.existsSync(destPath)) {

const path = require('path');
const absolutePath = path.resolve(destPath);
console.log(absolutePath);

react\.flowconfig

const oldConfig = String(fs.readFileSync(destPath));
const newConfig = String(fs.readFileSync(srcPath));

if (oldConfig !== newConfig) {

console.log(oldConfig === newConfig);

console.log(
  'Running Flow on the ' + chalk.yellow(renderer) + ' renderer...',
);

spawn(cmd, args, {
  // Allow colors to pass through:
  stdio: 'inherit',
}).on('close', function (code) {
  if (code !== 0) {
    console.error(
      'Flow failed for the ' + chalk.red(renderer) + ' renderer',
    );
    console.log();
    process.exit(code);
  } else {
    console.log(
      'Flow passed for the ' + chalk.green(renderer) + ' renderer',
    );
    resolve();
  }
});

process.on('unhandledRejection', err => {
  throw err;
});

spawn(cmd, args, {
  // Allow colors to pass through:
  stdio: 'inherit',
})

react\scripts\flow\..\..\node_modules\.bin\flow.cmd

runFlow(primaryRenderer.shortName, ['status']);

{
  // Allow colors to pass through:
  stdio: 'inherit',
}

const process1 = spawn('ls', ['-la'], { stdio: 'inherit' });  // 出力される
const process2 = spawn('ls', ['-la']);  // 出力されない

spawn(cmd, args, {
  // Allow colors to pass through:
  stdio: 'inherit',
})

}).on('close', function (code) {

if (code !== 0) {
  console.error(
    'Flow failed for the ' + chalk.red(renderer) + ' renderer',
  );
  console.log();
  process.exit(code);
} else {
  console.log(
    'Flow passed for the ' + chalk.green(renderer) + ' renderer',
  );
  resolve();
}

spawn(cmd, args, {
  stdio: 'inherit',
})

C:\Users\ユーザ名\Downloads\react\scripts\flow\..\..\node_modules\.bin\flow.cmd

C:\Users\ユーザ名\Downloads\react\scripts\flow\..\..\node_modules\.bin\flow.cmd status

C:\Users\ユーザ名\Downloads\react\node_modules\.bin\flow.cmd status

/c/Users/ユーザ名/Downloads/react/node_modules/.bin/flow.cmd status

@IF EXIST "%~dp0\node.exe" (
  "%~dp0\node.exe"  "%~dp0\..\flow-bin\cli.js" %*
) ELSE (
  @SETLOCAL
  @SET PATHEXT=%PATHEXT:;.JS;=;%
  node  "%~dp0\..\flow-bin\cli.js" %*
)

yarn flow dom-node

Start-Process powershell -Verb RunAs -ArgumentList "-NoExit", "-Command", "Set-Location -Path '$PWD'"

errno: -4071,
code: 'EINVAL',
syscall: 'spawn'

#!/bin/sh
basedir=$(dirname "$(echo "$0" | sed -e 's,\\,/,g')")

case `uname` in
    *CYGWIN*) basedir=`cygpath -w "$basedir"`;;
esac

if [ -x "$basedir/node" ]; then
  "$basedir/node"  "$basedir/../flow-bin/cli.js" "$@"
  ret=$?
else 
  node  "$basedir/../flow-bin/cli.js" "$@"
  ret=$?
fi
exit $ret

/c/Users/ユーザ名/Downloads/react/node_modules/.bin/flow.cmd status

"flow.pathToFlow": "/c/Users/ユーザ名/Downloads/react/node_modules/.bin/flow",
"flow.useNPMPackagedFlow": true,
"javascript.validate.enable": false

import * as React from 'react';

const ReactSharedInternals =
  React.__CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE;

export default ReactSharedInternals;

export {
  __CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE,
  // ...
} from './src/ReactClient';

import ReactSharedInternals from './ReactSharedInternalsClient';
//...
export {
  // ...
  ReactSharedInternals as __CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE,
  // ...
};

import type {Dispatcher} from 'react-reconciler/src/ReactInternalTypes';
import type {AsyncDispatcher} from 'react-reconciler/src/ReactInternalTypes';
import type {BatchConfigTransition} from 'react-reconciler/src/ReactFiberTracingMarkerComponent';

export type SharedStateClient = {
  H: null | Dispatcher, // ReactCurrentDispatcher for Hooks
  A: null | AsyncDispatcher, // ReactCurrentCache for Cache
  T: null | BatchConfigTransition, // ReactCurrentBatchConfig for Transitions
  S: null | ((BatchConfigTransition, mixed) => void), // onStartTransitionFinish

  // DEV-only

  // ReactCurrentActQueue
  actQueue: null | Array<RendererTask>,

  // Used to reproduce behavior of `batchedUpdates` in legacy mode.
  isBatchingLegacy: boolean,
  didScheduleLegacyUpdate: boolean,

  // Tracks whether something called `use` during the current batch of work.
  // Determines whether we should yield to microtasks to unwrap already resolved
  // promises without suspending.
  didUsePromise: boolean,

  // Track first uncaught error within this act
  thrownErrors: Array<mixed>,

  // ReactDebugCurrentFrame
  getCurrentStack: null | (() => string),
};

export type RendererTask = boolean => RendererTask | null;

const ReactSharedInternals: SharedStateClient = ({
  H: null,
  A: null,
  T: null,
  S: null,
}: any);

if (__DEV__) {
  ReactSharedInternals.actQueue = null;
  ReactSharedInternals.isBatchingLegacy = false;
  ReactSharedInternals.didScheduleLegacyUpdate = false;
  ReactSharedInternals.didUsePromise = false;
  ReactSharedInternals.thrownErrors = [];
  // Stack implementation injected by the current renderer.
  ReactSharedInternals.getCurrentStack = (null: null | (() => string));
}

export default ReactSharedInternals;