Add file.

Author: jaywcjlove

.gitignore

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+node_modules

README.md

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+open-browsers
+---
+
+Attempts to open the browser with a given URL.
+On Mac OS X, attempts to reuse an existing Chrome tab via AppleScript.
+Otherwise, falls back to [opn](https://github.com/sindresorhus/opn) behavior.
+
+`open-browsers` form [react-dev-utils](https://github.com/facebook/create-react-app/blob/next/packages/react-dev-utils/openBrowser.js)
+
+
+> openBrowsers(url: string): boolean 
+
+```js
+var path = require('path');
+var openBrowsers = require('open-browsers');
+
+if (openBrowsers('http://localhost:3000')) {
+  console.log('The browser tab has been opened!');
+}
+```

index.js

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+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * 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 chalk = require('colors-cli');
+var execSync = require('child_process').execSync;
+var spawn = require('cross-spawn');
+var opn = require('opn');
+
+// https://github.com/sindresorhus/opn#app
+var OSX_CHROME = 'google chrome';
+
+const Actions = Object.freeze({
+  NONE: 0,
+  BROWSER: 1,
+  SCRIPT: 2,
+});
+
+function getBrowserEnv() {
+  // Attempt to honor this environment variable.
+  // It is specific to the operating system.
+  // See https://github.com/sindresorhus/opn#app for documentation.
+  const value = process.env.BROWSER;
+  let action;
+  if (!value) {
+    // Default.
+    action = Actions.BROWSER;
+  } else if (value.toLowerCase().endsWith('.js')) {
+    action = Actions.SCRIPT;
+  } else if (value.toLowerCase() === 'none') {
+    action = Actions.NONE;
+  } else {
+    action = Actions.BROWSER;
+  }
+  return { action, value };
+}
+
+function executeNodeScript(scriptPath, url) {
+  const extraArgs = process.argv.slice(2);
+  const child = spawn('node', [scriptPath, ...extraArgs, url], {
+    stdio: 'inherit',
+  });
+  child.on('close', code => {
+    if (code !== 0) {
+      console.log();
+      console.log(
+        chalk.red(
+          'The script specified as BROWSER environment variable failed.'
+        )
+      );
+      console.log(chalk.cyan(scriptPath) + ' exited with code ' + code + '.');
+      console.log();
+      return;
+    }
+  });
+  return true;
+}
+
+function startBrowserProcess(browser, url) {
+  // If we're on OS X, the user hasn't specifically
+  // requested a different browser, we can try opening
+  // Chrome with AppleScript. This lets us reuse an
+  // existing tab when possible instead of creating a new one.
+  const shouldTryOpenChromeWithAppleScript =
+    process.platform === 'darwin' &&
+    (typeof browser !== 'string' || browser === OSX_CHROME);
+
+  if (shouldTryOpenChromeWithAppleScript) {
+    try {
+      // Try our best to reuse existing tab
+      // on OS X Google Chrome with AppleScript
+      execSync('ps cax | grep "Google Chrome"');
+      execSync('osascript openChrome.applescript "' + encodeURI(url) + '"', {
+        cwd: __dirname,
+        stdio: 'ignore',
+      });
+      return true;
+    } catch (err) {
+      // Ignore errors.
+    }
+  }
+
+  // Another special case: on OS X, check if BROWSER has been set to "open".
+  // In this case, instead of passing `open` to `opn` (which won't work),
+  // just ignore it (thus ensuring the intended behavior, i.e. opening the system browser):
+  // https://github.com/facebook/create-react-app/pull/1690#issuecomment-283518768
+  if (process.platform === 'darwin' && browser === 'open') {
+    browser = undefined;
+  }
+
+  // Fallback to opn
+  // (It will always open new tab)
+  try {
+    var options = { app: browser };
+    opn(url, options).catch(() => { }); // Prevent `unhandledRejection` error.
+    return true;
+  } catch (err) {
+    return false;
+  }
+}
+
+/**
+ * Reads the BROWSER evironment variable and decides what to do with it. Returns
+ * true if it opened a browser or ran a node.js script, otherwise false.
+ */
+function openBrowser(url) {
+  const { action, value } = getBrowserEnv();
+  switch (action) {
+    case Actions.NONE:
+      // Special case: BROWSER="none" will prevent opening completely.
+      return false;
+    case Actions.SCRIPT:
+      return executeNodeScript(value, url);
+    case Actions.BROWSER:
+      return startBrowserProcess(value, url);
+    default:
+      throw new Error('Not implemented.');
+  }
+}
+
+module.exports = openBrowser;

package-lock.json

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+{
+  "name": "open-browsers",
+  "version": "1.0.1",
+  "description": "Attempts to open the browser with a given URL. On Mac OS X, attempts to reuse an existing Chrome tab via AppleScript.",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "MIT",
+  "dependencies": {
+    "colors-cli": "^1.0.13",
+    "cross-spawn": "^6.0.5",
+    "opn": "^5.3.0"
+  }
+}