keywords: TypeScript, JavaScript Engine, Nodejs, Chrome, V8, Notes

Environment Setup for TypeScript

How to update TypeScript to latest version with npm
npm install -g typescript@latest

or

yarn global add typescript@latest  // if you use yarn package manager

Origin:
https://stackoverflow.com/a/42155457/1645289

Setup compilation environment for Visual Studio Code

1, Install compiler (tsc) of TypeScript:

npm install typescript -g

2, Create a directory as your project, named myproj.

3, Create a TypeScript source file under myproj, named hello.ts, and print a message in console:

let message: string = 'Hello';
console.log(message);

then compile source with command:

tsc hello.ts​

4, Address to directory myproj in command, then generate tsconfig.json using command:

tsc --init

Reference:
https://zhuanlan.zhihu.com/p/115675528

5, Go to your project directory and excute commands:

npm install typescript --save
npm install ts-node --save-dev

Reference:
https://cloud.tencent.com/developer/article/1760857

If you got error:

Error: Cannot find module 'typescript'

Go to your project directory and link typescript to the project:

cd myproj

npm link typescript

6, Run npx ts-node to test your source code:

npx ts-node hello.ts

Reference:
https://stackoverflow.com/a/65508481/1645289

7, Install extension TypeScript Debugger, then click Run -> Add Configuration -> select TS Debug:

8, Open directory myproj in Visual Studio Code, then press F5 or click Run -> Start Debugging.

Issue:

If you get error on Windows while Start Debugging:

tsc.ps1 cannot be loaded because running scripts is disabled on this system

Excute command using PowerShell as administrator, and select option A(ll):

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned

Reference:
https://stackoverflow.com/a/58801137/1645289

Now you would run debugging successfully.

Setup compilation environment for Intellij IDEA

Do first five above-side steps, then compile TypeScript source by clicking lable which was in the bottom of editor viewport, then debug your code.

TypeScript plugin is only usable for Intellij IDEA Ultimate Edition and WebStorm.

IntelliJ IDEA Plugins

IntelliJ IDEA (and WebStorm…) plugin to support ‘TypeScript’ as a run configuration
https://github.com/bluelovers/idea-run-typescript

Issues

Issue 2:

If you get error while Start Debugging:

D:\SDKs\nodejs\node.exe -r ts-node/register .vscode\launch.json
SyntaxError: D:\myproj\.vscode\launch.json: Unexpected token / in JSON at position 7
    at parse (<anonymous>)
    at Object.Module._extensions..json (internal/modules/cjs/loader.js:1128:22)
    at Module.load (internal/modules/cjs/loader.js:950:32)
    at Function.Module._load (internal/modules/cjs/loader.js:790:12)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)
    at internal/main/run_main_module.js:17:47
Process exited with code 1

Or:

Debugger attached.
Waiting for the debugger to disconnect...
d:\myproj\hello.ts:1
let message: string = 'Hello World';
           ^

SyntaxError: Unexpected token ':'
    at wrapSafe (internal/modules/cjs/loader.js:1001:16)
    at Module._compile (internal/modules/cjs/loader.js:1049:27)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
    at Module.load (internal/modules/cjs/loader.js:950:32)
    at Function.Module._load (internal/modules/cjs/loader.js:790:12)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)
    at internal/main/run_main_module.js:17:47
Process exited with code 1

It’s the bug of extentsion TypeScript Debugger of Visual Studio Code.
https://github.com/microsoft/vscode/issues/45616

Recommended to use IntelliJ IDEA intead of Visual Studio Code.

Common API

How to print call stack when error occurs.
try {
   // Code throwing an exception
} catch(e) {
  console.log(e.stack);
}

Origin:
https://stackoverflow.com/a/4200200/1645289

string format
var text = "blah blah";
var strTest = `This is a ${text}`;
console.log(strTest);

String interpolation in Typescript, replacing ‘placeholders’ with variables
https://stackoverflow.com/a/52196435/1645289

Declare variables and export them
export namespace RoleCreationDefine
{
    const Test01: string = "Neil Wang";
}
Declare enum and export them
export const enum ESexType {
    None,
    Male,
    Female,
}
Declare dictionary and export it

We can try with built-in typescript advanced type called Record<K, T>:

interface MyInterface {
    data: Record<string, Item>;
}

Put everything together here

interface Item {
    id: string;
    name: string;
}

interface MyInterface {
    data: Record<string, Item>;
}

export const obj: MyInterface = {
    data: {
        "123": { id: "123", name: "something" }
    }
};

Origin: Dictionary type in TypeScript
https://stackoverflow.com/a/56353483/1645289

Frameworks & Libraries

V8 C++ Wrapping

Getting started with embedding V8
https://v8.dev/docs/embed

Bind C++ functions and classes into V8 JavaScript engine
https://github.com/pmed/v8pp

Lua

TypeScriptToLua. Typescript to lua transpiler.
https://github.com/TypeScriptToLua/TypeScriptToLua

NPM

Issues

Error on running npm install:

error code EPERM
error syscall open
error path D:\GamesLibrary\EpicGamesStore\UE_4.27\Engine\Source\Programs\PixelStreaming\WebServers\SignallingWebServer\package-lock.json
error errno -4048
error Error: EPERM: operation not permitted, open 'D:\GamesLibrary\EpicGamesStore\UE_4.27\Engine\Source\Programs\PixelStreaming\WebServers\SignallingWebServer\package-lock.json'
error  [Error: EPERM: operation not permitted, open 'D:\GamesLibrary\EpicGamesStore\UE_4.27\Engine\Source\Programs\PixelStreaming\WebServers\SignallingWebServer\package-lock.json'] {
error   errno: -4048,
error   code: 'EPERM',
error   syscall: 'open',
error   path: 'D:\\GamesLibrary\\EpicGamesStore\\UE_4.27\\Engine\\Source\\Programs\\PixelStreaming\\WebServers\\SignallingWebServer\\package-lock.json'
error }
error The operation was rejected by your operating system.
error It's possible that the file was already in use (by a text editor or antivirus),
error or that you lack permissions to access it.
error
error If you believe this might be a permissions issue, please double-check the
error permissions of the file and its containing directories, or try running
error the command again as root/Administrator.
verbose exit -4048

Solution:

npm cache clean --force

npm install -g npm@latest --force

Origin:
https://stackoverflow.com/a/59045453/1645289

References

Fragments

Mastering mapped types in TypeScript
https://blog.logrocket.com/mastering-mapped-types-typescript/

Performance

Why is TypeScript surpassing Python?
https://blog.logrocket.com/why-is-typescript-surpassing-python/

Books

Mastering TypeScript: Build enterprise-ready, modular web applications using TypeScript 4 and modern frameworks, 4th Edition 4th Edition (April 23, 2021)
https://www.amazon.com/Mastering-TypeScript-enterprise-ready-applications-frameworks-ebook/dp/B091D7P533/


“As a child I felt myself to be alone, and I am still, because I know things and must hint at things which others apparently know nothing of, and for the most part do not want to know.” ― Carl Gustav Jung, Memories, Dreams, Reflections