HW 9 done

09/.gitignore

@@ -0,0 +1,23 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+/.pnp
+.pnp.js
+
+# testing
+/coverage
+
+# production
+/build
+
+# misc
+.DS_Store
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*

09/README.md

@@ -0,0 +1,70 @@
+# Getting Started with Create React App
+
+This project was bootstrapped with [Create React App](https://github.com/facebook/create-react-app).
+
+## Available Scripts
+
+In the project directory, you can run:
+
+### `npm start`
+
+Runs the app in the development mode.\
+Open [http://localhost:3000](http://localhost:3000) to view it in your browser.
+
+The page will reload when you make changes.\
+You may also see any lint errors in the console.
+
+### `npm test`
+
+Launches the test runner in the interactive watch mode.\
+See the section about [running tests](https://facebook.github.io/create-react-app/docs/running-tests) for more information.
+
+### `npm run build`
+
+Builds the app for production to the `build` folder.\
+It correctly bundles React in production mode and optimizes the build for the best performance.
+
+The build is minified and the filenames include the hashes.\
+Your app is ready to be deployed!
+
+See the section about [deployment](https://facebook.github.io/create-react-app/docs/deployment) for more information.
+
+### `npm run eject`
+
+**Note: this is a one-way operation. Once you `eject`, you can't go back!**
+
+If you aren't satisfied with the build tool and configuration choices, you can `eject` at any time. This command will remove the single build dependency from your project.
+
+Instead, it will copy all the configuration files and the transitive dependencies (webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except `eject` will still work, but they will point to the copied scripts so you can tweak them. At this point you're on your own.
+
+You don't have to ever use `eject`. The curated feature set is suitable for small and middle deployments, and you shouldn't feel obligated to use this feature. However we understand that this tool wouldn't be useful if you couldn't customize it when you are ready for it.
+
+## Learn More
+
+You can learn more in the [Create React App documentation](https://facebook.github.io/create-react-app/docs/getting-started).
+
+To learn React, check out the [React documentation](https://reactjs.org/).
+
+### Code Splitting
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/code-splitting](https://facebook.github.io/create-react-app/docs/code-splitting)
+
+### Analyzing the Bundle Size
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size](https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size)
+
+### Making a Progressive Web App
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app](https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app)
+
+### Advanced Configuration
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/advanced-configuration](https://facebook.github.io/create-react-app/docs/advanced-configuration)
+
+### Deployment
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/deployment](https://facebook.github.io/create-react-app/docs/deployment)
+
+### `npm run build` fails to minify
+
+This section has moved here: [https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify](https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify)

09/package.json

@@ -0,0 +1,38 @@
+{
+  "name": "09",
+  "version": "0.1.0",
+  "private": true,
+  "dependencies": {
+    "@testing-library/jest-dom": "^5.16.5",
+    "@testing-library/react": "^13.3.0",
+    "@testing-library/user-event": "^13.5.0",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "react-scripts": "5.0.1",
+    "web-vitals": "^2.1.4"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build",
+    "test": "react-scripts test",
+    "eject": "react-scripts eject"
+  },
+  "eslintConfig": {
+    "extends": [
+      "react-app",
+      "react-app/jest"
+    ]
+  },
+  "browserslist": {
+    "production": [
+      ">0.2%",
+      "not dead",
+      "not op_mini all"
+    ],
+    "development": [
+      "last 1 chrome version",
+      "last 1 firefox version",
+      "last 1 safari version"
+    ]
+  }
+}

09/public/index.html

@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <link rel="icon" href="%PUBLIC_URL%/favicon.ico" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <meta name="theme-color" content="#000000" />
+    <meta
+      name="description"
+      content="Web site created using create-react-app"
+    />
+    <link rel="apple-touch-icon" href="%PUBLIC_URL%/logo192.png" />
+    <!--
+      manifest.json provides metadata used when your web app is installed on a
+      user's mobile device or desktop. See https://developers.google.com/web/fundamentals/web-app-manifest/
+    -->
+    <link rel="manifest" href="%PUBLIC_URL%/manifest.json" />
+    <!--
+      Notice the use of %PUBLIC_URL% in the tags above.
+      It will be replaced with the URL of the `public` folder during the build.
+      Only files inside the `public` folder can be referenced from the HTML.
+
+      Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
+      work correctly both with client-side routing and a non-root public URL.
+      Learn how to configure a non-root public URL by running `npm run build`.
+    -->
+    <title>React App</title>
+  </head>
+  <body>
+    <noscript>You need to enable JavaScript to run this app.</noscript>
+    <div id="root"></div>
+    <!--
+      This HTML file is a template.
+      If you open it directly in the browser, you will see an empty page.
+
+      You can add webfonts, meta tags, or analytics to this file.
+      The build step will place the bundled scripts into the <body> tag.
+
+      To begin the development, run `npm start` or `yarn start`.
+      To create a production bundle, use `npm run build` or `yarn build`.
+    -->
+  </body>
+</html>

09/public/manifest.json

@@ -0,0 +1,25 @@
+{
+  "short_name": "React App",
+  "name": "Create React App Sample",
+  "icons": [
+    {
+      "src": "favicon.ico",
+      "sizes": "64x64 32x32 24x24 16x16",
+      "type": "image/x-icon"
+    },
+    {
+      "src": "logo192.png",
+      "type": "image/png",
+      "sizes": "192x192"
+    },
+    {
+      "src": "logo512.png",
+      "type": "image/png",
+      "sizes": "512x512"
+    }
+  ],
+  "start_url": ".",
+  "display": "standalone",
+  "theme_color": "#000000",
+  "background_color": "#ffffff"
+}

09/public/robots.txt

@@ -0,0 +1,3 @@
+# https://www.robotstxt.org/robotstxt.html
+User-agent: *
+Disallow:

09/src/App.css

@@ -0,0 +1,38 @@
+.App {
+  text-align: center;
+}
+
+.App-logo {
+  height: 40vmin;
+  pointer-events: none;
+}
+
+@media (prefers-reduced-motion: no-preference) {
+  .App-logo {
+    animation: App-logo-spin infinite 20s linear;
+  }
+}
+
+.App-header {
+  background-color: #282c34;
+  min-height: 100vh;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  font-size: calc(10px + 2vmin);
+  color: white;
+}
+
+.App-link {
+  color: #61dafb;
+}
+
+@keyframes App-logo-spin {
+  from {
+    transform: rotate(0deg);
+  }
+  to {
+    transform: rotate(360deg);
+  }
+}

09/src/App.js

@@ -0,0 +1,135 @@
+// makeProfileTimer
+
+// Напишите функцию makeProfileTimer, которая служит для замера времени выполнения другого кода и работает следующим образом:
+
+// var timer = makeProfileTimer()
+// alert('Замеряем время работы этого alert');  некий код, время выполнения которого мы хотим измерить с высокой точностью
+// alert(timer());                              alert должен вывести время в микросекундах от выполнения makeProfileTimer до момента вызова timer(),
+//                                              т. е. измерить время выполнения alert
+
+// Используйте performance.now()
+
+function makeProfileTimer() {
+    var t1 = performance.now();
+    return function () {
+        var t2 = performance.now();
+        return (t2 - t1);
+    };
+};
+
+var timer = makeProfileTimer();
+alert('Замеряем время работы этого alert');
+alert(timer());
+
+// makeSaver
+
+// Напишите функцию makeSaver, которая:
+
+// var saver = makeSaver(Math.random)   создает функцию-хранилище результата переданной в качестве параметра функции (Math.random 
+//                                      в примере). На этом этапе Math.random НЕ вызывается
+// var value1 = saver()                 saver вызывает переданную в makeSaver функцию, запоминает результат и возвращает его
+// var value2 = saver()                 saver в дальнейшем просто хранит результат функции, и более НЕ вызывает переданную 
+//                                      в makeSaver функцию;
+// value1 === value2                    всегда true
+
+// var saver2 = makeSaver(() => console.log('saved function called') || [null, undefined, false, '', 0, Math.random()][Math.ceil(Math.random() * 6)])
+// var value3 = saver2()
+// var value4 = saver2()
+
+// value3 === value4 // тоже должно быть true
+
+// let namePrompt = prompt.bind(window, 'Как тебя зовут?')
+// let nameSaver = makeSaver(namePrompt)
+// alert(`Привет! Prompt еще не было!`)
+// alert(`Привет ${nameSaver()}. Только что запустился prompt, первый и последний раз`)
+// alert(`Слушай, ${nameSaver()}, го пить пиво. Ведь prompt был только один раз`)
+
+// Таким образом makeSaver решает две задачи:
+
+// * Навсегда сохраняет результат функции.Это актуально, например, для Math.random.
+// * Действует лениво, то есть вызывает Math.random только тогда, когда результат действительно нужен.
+// Если же по каким - то причинам значение не понадобится, то Math.random даже не будет вызван
+
+function makeSaver(callback) {
+    let result, executed = !1;
+    return function () {
+        return executed ? result : (executed = !0, res = callback());
+    };
+};
+
+var saver = makeSaver(Math.random)
+
+let value1 = saver();
+let value2 = saver();
+value1 === value2;
+
+function fun() {
+    return console.log('saved function called') || [null, undefined, false, '', 0, Math.random()][Math.ceil(Math.random() * 6)]
+}
+
+var saver2 = makeSaver(fun)
+
+var value3 = saver2()
+var value4 = saver2()
+
+value3 === value4
+
+let namePrompt = prompt.bind(window, 'Как тебя зовут?');
+let nameSaver = makeSaver(namePrompt);
+alert(`Привет! Prompt еще не было!`)
+alert(`Привет ${nameSaver()}. Только что запустился prompt, первый и последний раз`)
+alert(`Слушай, ${nameSaver()}, го пить пиво. Ведь prompt был только один раз`)
+
+// myBind
+
+// Изучите встроенную функцию bind, и сделайте свою версию, которая позволит определить "значение по умолчанию" не только для первых параметров, 
+// но для любых других, например для степени в Math.pow:
+
+// var pow5 = myBind(Math.pow, Math, [undefined, 5])    первый параметр - функция для биндинга значений по умолчанию, 
+//                                                      второй - this для этой функции, третий - массив, в котором undefined означает
+//                                                      параметры, которые должны передаваться при вызове,
+//                                                      а другие значения являются значениями по умолчанию:
+// var cube = myBind(Math.pow, Math, [undefined, 3])    cube возводит число в куб
+
+// pow5(2) // => 32,                                    вызывает Math.pow(2,5), соотнесите с [undefined, 5]
+// cube(3) // => 27
+
+// var chessMin = myBind(Math.min, Math, [undefined, 4, undefined, 5, undefined, 8, undefined, 9])
+// chessMin(-1, -5, 3, 15)                              вызывает Math.min(-1, 4, -5, 5, 3, 8, 15, 9), результат -5
+
+// var zeroPrompt = myBind(prompt, window, [undefined, "0"])    аналогично, только теперь задается "0" как текст по умолчанию в prompt, 
+//                                                              а текст приглашения пользователя задается при вызове zeroPrompt
+// var someNumber = zeroPrompt("Введите число")                 вызывает prompt("Введите число","0")
+
+// myBind((...params) => params.join(''), null, [undefined, 'b', undefined, undefined, 'e', 'f'])('a', 'c', 'd') === 'abcdef'
+// Массив, который идет третьим параметром определяет, какие поля должны подменяться значением по умолчанию, 
+// а какие - задаваться в последствии(undefined).
+
+let myBind = function (fn, context, arr) {
+    return function () {
+        let index = 0
+        var fnArgs = [].slice.call(arguments);
+        return fn.apply(context, arr.map(i => {
+            if (i === undefined) {
+                let newValue = fnArgs[index]
+                index++
+                return newValue
+            }
+            else return i
+        }));
+    };
+};
+
+var pow5 = myBind(Math.pow, Math, [undefined, 5]);
+var cube = myBind(Math.pow, Math, [undefined, 3]);
+alert(pow5(2));
+alert(cube(3));
+
+var chessMin = myBind(Math.min, Math, [undefined, 4, undefined, 5, undefined, 8, undefined, 9])
+chessMin(-1, -5, 3, 15);
+
+var zeroPrompt = myBind(prompt, window, [undefined, "0"])
+var someNumber = zeroPrompt("Введите число")
+alert(someNumber);
+
+myBind((...params) => params.join(''), null, [undefined, 'b', undefined, undefined, 'e', 'f'])('a', 'c', 'd') === 'abcdef'

09/src/App.test.js

@@ -0,0 +1,8 @@
+import { render, screen } from '@testing-library/react';
+import App from './App';
+
+test('renders learn react link', () => {
+  render(<App />);
+  const linkElement = screen.getByText(/learn react/i);
+  expect(linkElement).toBeInTheDocument();
+});

09/src/index.css

@@ -0,0 +1,13 @@
+body {
+  margin: 0;
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
+    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
+    sans-serif;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+code {
+  font-family: source-code-pro, Menlo, Monaco, Consolas, 'Courier New',
+    monospace;
+}

09/src/index.js

@@ -0,0 +1,17 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import './index.css';
+import App from './App';
+import reportWebVitals from './reportWebVitals';
+
+const root = ReactDOM.createRoot(document.getElementById('root'));
+root.render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+);
+
+// If you want to start measuring performance in your app, pass a function
+// to log results (for example: reportWebVitals(console.log))
+// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
+reportWebVitals();

09/src/reportWebVitals.js

@@ -0,0 +1,13 @@
+const reportWebVitals = onPerfEntry => {
+  if (onPerfEntry && onPerfEntry instanceof Function) {
+    import('web-vitals').then(({ getCLS, getFID, getFCP, getLCP, getTTFB }) => {
+      getCLS(onPerfEntry);
+      getFID(onPerfEntry);
+      getFCP(onPerfEntry);
+      getLCP(onPerfEntry);
+      getTTFB(onPerfEntry);
+    });
+  }
+};
+
+export default reportWebVitals;

09/src/setupTests.js

@@ -0,0 +1,5 @@
+// jest-dom adds custom jest matchers for asserting on DOM nodes.
+// allows you to do things like:
+// expect(element).toHaveTextContent(/react/i)
+// learn more: https://github.com/testing-library/jest-dom
+import '@testing-library/jest-dom';