ToCode

// "noImplicitAny": true,                            /* Enable error reporting for expressions and declarations with an implied 'any' type. */
    // "strictNullChecks": true,                         /* When type checking, take into account 'null' and 'undefined'. */
    // "strictFunctionTypes": true,                      /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
    // "strictBindCallApply": true,                      /* Check that the arguments for 'bind', 'call', and 'apply' methods match the original function. */
    // "strictPropertyInitialization": true,             /* Check for class properties that are declared but not set in the constructor. */
    // "noImplicitThis": true,                           /* Enable error reporting when 'this' is given the type 'any'. */
    // "useUnknownInCatchVariables": true,               /* Default catch clause variables as 'unknown' instead of 'any'. */
    // "alwaysStrict": true,                             /* Ensure 'use strict' is always emitted. */
    // "noUnusedLocals": true,                           /* Enable error reporting when local variables aren't read. */
    // "noUnusedParameters": true,                       /* Raise an error when a function parameter isn't read. */
    // "exactOptionalPropertyTypes": true,               /* Interpret optional property types as written, rather than adding 'undefined'. */
    // "noImplicitReturns": true,                        /* Enable error reporting for codepaths that do not explicitly return in a function. */
    // "noFallthroughCasesInSwitch": true,               /* Enable error reporting for fallthrough cases in switch statements. */
    // "noUncheckedIndexedAccess": true,                 /* Add 'undefined' to a type when accessed using an index. */
    // "noImplicitOverride": true,                       /* Ensure overriding members in derived classes are marked with an override modifier. */
    // "noPropertyAccessFromIndexSignature": true,       /* Enforces using indexed accessors for keys declared using an indexed type. */
    // "allowUnusedLabels": true,                        /* Disable error reporting for unused labels. */
    // "allowUnreachableCode": true,                     /* Disable error reporting for unreachable code. */

    /* Completeness */
    // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
    "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
  }
}

// "outDir": "./",                                   /* Specify an output folder for all emitted files. */

"outDir": "./dist",

"scripts": {
  "build": "tsc",
  "dev": "ts-node main.ts",
  "test": "echo \"Error: no test specified\" && exit 1"
},

$ npm run build

$ node dist/main.js

// "declaration": true,                              /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
    // "declarationMap": true,                           /* Create sourcemaps for d.ts files. */
    // "emitDeclarationOnly": true,                      /* Only output d.ts files and not JavaScript files. */
    // "sourceMap": true,                                /* Create source map files for emitted JavaScript files. */
    // "outFile": "./",                                  /* Specify a file that bundles all outputs into one JavaScript file. If 'declaration' is true, also designates a file that bundles all .d.ts output. */
    // "outDir": "./",                                   /* Specify an output folder for all emitted files. */
    // "removeComments": true,                           /* Disable emitting comments. */
    // "noEmit": true,                                   /* Disable emitting files from a compilation. */
    // "importHelpers": true,                            /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
    // "importsNotUsedAsValues": "remove",               /* Specify emit/checking behavior for imports that are only used for types. */
    // "downlevelIteration": true,                       /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
    // "sourceRoot": "",                                 /* Specify the root path for debuggers to find the reference source code. */
    // "mapRoot": "",                                    /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSourceMap": true,                          /* Include sourcemap files inside the emitted JavaScript. */
    // "inlineSources": true,                            /* Include source code in the sourcemaps inside the emitted JavaScript. */
    // "emitBOM": true,                                  /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
    // "newLine": "crlf",                                /* Set the newline character for emitting files. */
    // "stripInternal": true,                            /* Disable emitting declarations that have '@internal' in their JSDoc comments. */
    // "noEmitHelpers": true,                            /* Disable generating custom helper functions like '__extends' in compiled output. */
    // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
    // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
    // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */

    /* Interop Constraints */
    // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */
    // "allowSyntheticDefaultImports": true,             /* Allow 'import x from y' when a module doesn't have a default export. */
    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
    // "preserveSymlinks": true,                         /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */

    /* Type Checking */
    "strict": true,                                      /* Enable all strict type-checking options. */

// "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */

    /* Language and Environment */
    "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
    // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
    // "jsx": "preserve",                                /* Specify what JSX code is generated. */
    // "experimentalDecorators": true,                   /* Enable experimental support for TC39 stage 2 draft decorators. */
    // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
    // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */
    // "jsxFragmentFactory": "",                         /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
    // "jsxImportSource": "",                            /* Specify module specifier used to import the JSX factory functions when using 'jsx: react-jsx*'. */
    // "reactNamespace": "",                             /* Specify the object invoked for 'createElement'. This only applies when targeting 'react' JSX emit. */
    // "noLib": true,                                    /* Disable including any library files, including the default lib.d.ts. */
    // "useDefineForClassFields": true,                  /* Emit ECMAScript-standard-compliant class fields. */
    // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */

    /* Modules */
    "module": "commonjs",                                /* Specify what module code is generated. */
    // "rootDir": "./",                                  /* Specify the root folder within your source files. */
    // "moduleResolution": "node",                       /* Specify how TypeScript looks up a file from a given module specifier. */
    // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
    // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
    // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
    // "typeRoots": [],                                  /* Specify multiple folders that act like './node_modules/@types'. */
    // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
    // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
    // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
    // "resolveJsonModule": true,                        /* Enable importing .json files. */
    // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */

    /* JavaScript Support */
    // "allowJs": true,                                  /* Allow JavaScript files to be a part of your program. Use the 'checkJS' option to get errors from these files. */
    // "checkJs": true,                                  /* Enable error reporting in type-checked JavaScript files. */
    // "maxNodeModuleJsDepth": 1,                        /* Specify the maximum folder depth used for checking JavaScript files from 'node_modules'. Only applicable with 'allowJs'. */

    /* Emit */

function printTimes(text: string, times: number = 5) {
  for (let i=0; i < times; i++) {
    console.log(text);
  }
}

printTimes("Hello World!", 2);

$ npm init -y

$ npm install --save-dev ts-node

{
  "name": "hello-node-world",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "dev": "ts-node main.ts",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "ts-node": "10.9.1"
  }
}

$ npm run dev

export const foo = "bar";

import { foo } from './const';

function printTimes(text: string, times: number = 5) {
  for (let i=0; i < times; i++) {
    console.log(text);
  }
  console.log(foo);
}

printTimes("Hello World!", 2);

$ npm install --save-dev typescript

$ npx tsc --init

{
  "compilerOptions": {
    /* Visit https://aka.ms/tsconfig to read more about this file */

    /* Projects */
    // "incremental": true,                              /* Save .tsbuildinfo files to allow for incremental compilation of projects. */
    // "composite": true,                                /* Enable constraints that allow a TypeScript project to be used with project references. */
    // "tsBuildInfoFile": "./.tsbuildinfo",              /* Specify the path to .tsbuildinfo incremental compilation file. */
    // "disableSourceOfProjectReferenceRedirect": true,  /* Disable preferring source files instead of declaration files when referencing composite projects. */
    // "disableSolutionSearching": true,                 /* Opt a project out of multi-project reference checking when editing. */

function TodoList() {
  const [items, setItems] = useState([
    { id: 1, text: "one", done: false },
    { id: 2, text: "two", done: false },
    { id: 3, text: "three", done: false },
    { id: 4, text: "four", done: false }
  ]);

  function toggle(item) {
    setItems((oldItems) =>
      oldItems.map((it) => (it.id === item.id ? { ...it, done: !it.done } : it))
    );
  }

  return (
    <>
      <p>Open Tasks: {items.filter((it) => !it.done).length}</p>
      <ul>
        {items.map((i) => (
          <li key={i.id}>
            <label>
              <input
                type="checkbox"
                checked={i.done}
                onChange={(e) => toggle(i)}
              />
              {i.text}
            </label>
          </li>
        ))}
      </ul>
    </>
  );
}

{portal &&
  createPortal(
    <p>Open Tasks: {items.filter((it) => !it.done).length}</p>,
    portal
  )}

export default function App() {
  const [portal, setPortal] = useState(null);

  return (
    <div className="App">
      <div ref={(node) => setPortal(node)} />
      <TodoList portal={portal} />
    </div>
  );
}

function MyPlayer() {
    const el = useRef(null);
    const player = useRef(null);
    
    useEffect(() => {
        if (el.current) {
            player.current = new VideoPlayer(el.current);
        }
    }, []);
    
    return (<div ref={el} /);
}

function BuggyMeasureExample() {
  const [height, setHeight] = useState(0);

  const measuredRef = useRef(null);
  useEffect(() => {
    const node = measuredRef.current;
    if (node !== null) {
      setHeight(node.getBoundingClientRect().height);
    } else {
      setHeight(-1);
    }
  }, [measuredRef.current]);

  return (
    <>
      <Child ref={measuredRef} />
      <h2>The above header is {Math.round(height)}px tall</h2>
    </>
  );
}

const Child = React.forwardRef(function Child(props, ref) {
  const [visible, setVisible] = useState(true);

  function toggle() {
    setVisible((v) => !v);
  }

  return (
    <>
      {visible && <h1 ref={ref}>Hello world</h1>}
      <button onClick={toggle}>Toggle</button>
    </>
  );
});

function MeasureExample() {
  const [height, setHeight] = useState(0);

  const measuredRef = useCallback((node) => {
    if (node !== null) {
      setHeight(node.getBoundingClientRect().height);
    } else {
      setHeight(-1);
    }
  }, []);

  return (
    <>
      <Child ref={measuredRef} />
      <h2>The above header is {Math.round(height)}px tall</h2>
    </>
  );
}

SyntaxError: Cannot use import statement outside a module

{
  "name": "games",
  "type": "module",
  "version": "1.0.0",
  "description": "",
  "main": "hello.js",
  "keywords": [],
  "author": "",
  "license": "ISC"
}

import * as readline from 'node:readline/promises';
import { stdin as input, stdout as output } from 'node:process';

const rl = readline.createInterface({ input, output });
const question = "Who are you? "

while(true) {
  const answer = await rl.question(question);
  console.log(`Welcome, ${answer}`);
}

$ node --watch hello.mjs

{
  "text": "Who goes there?"
}

import data from './data.json' assert { type: "json" };

console.log(data.text);

const { data, error, isLoading } = useGetNotesQuery();

endpoints: (builder) => ({
  getNotes: builder.query({
    query: ({ page = 1, limit = 20 }) => `/notes?page=${page}&limit=${limit}`
  }),

const response = await (await fetch(url)).json();

const { data, error } = useSWR(url);

// Need to use the React-specific entry point to import createApi
import { createApi, fetchBaseQuery } from "@reduxjs/toolkit/query/react";

// Define a service using a base URL and expected endpoints
export const notesApi = createApi({
  reducerPath: "notesApi",
  baseQuery: fetchBaseQuery({
    baseUrl: "https://634fa864df22c2af7b5647a4.mockapi.io/api/v1/"
  }),
  endpoints: (builder) => ({
    getNotes: builder.query({
      query: () => `/notes`
    }),
    getNote: builder.query({
      query: (noteId) => `/notes/${noteId}`
    })
  })
});

export default notesApi;

http://www.tocode.co.il?foo=10&bar=20

const url = new URL("http://www.tocode.co.il?foo=10&bar=20");

> url.searchParams.get('foo')
'10'

> url.searchParams.get('bar')
'20'

> url.searchParams.set('foo', 'new value')
> url.searchParams.set('newKey', 12)

> url.toString()
'http://www.tocode.co.il/?foo=new+value&bar=20&newKey=12'