defaultChecks() {
    const author = { firstName: "Vahid", lastName: "N" };
    console.log(author.lastname);
    author.lastName.trimStart();
    author.firstName.charCodeAt("1");
  }

  > npm install -g tslint typescript

{
    "compilerOptions": {
        "strictNullChecks": true
    }
}

  getSessionItem(key: string): any {
    const data = window.sessionStorage.getItem(key);
    return JSON.parse(data);
  }

[ts]
Argument of type 'string | null' is not assignable to parameter of type 'string'.
Type 'null' is not assignable to type 'string'.
const data: string | null

  getSessionItem(key: string): any {
    const data = window.sessionStorage.getItem(key);
    if (data) {
      return JSON.parse(data);
    } else {
      return null;
    }
  }

  noImplicitReturns(a: number) {
    if (a > 10) {
      return a;
    }
    // No return in this branch
  }

{
    "compilerOptions": {
        "noImplicitReturns": true
    }
}

 [ts] Not all code paths return a value.

{
    "compilerOptions": {
        "allowUnreachableCode": false
    }
}

    allowUnreachableCode() {
      if (false) {
        console.log("Unreachable code");
      }
      const a = 1;
      if (a > 0) {
        return 10; // reachable code
      }
      return 0;
      console.log("Unreachable code");
    }

  unusedLocals() {
    const a = "foo"; // Error: 'a' is declared but its value is never read
    return "bar";
  }

  unusedParameters(n: number) {
    n = 0; // Never read
  }

{
    "compilerOptions": {
        "noUnusedLocals": true,
        "noUnusedParameters": true
    }
}

[ts] 'a' is declared but its value is never read.
[ts] 'n' is declared but its value is never read.

  excessPropertyForObjectLiterals() {
    let x: { foo: number };
    x = { foo: 1, baz: 2 };  // Error, excess property 'baz'
    let y: { foo: number, bar?: number };
    y = { foo: 1, baz: 2 };  // Error, excess property 'baz'
  }

{
    "compilerOptions": {
        "suppressExcessPropertyErrors": false
    }
}

[ts]
Type '{ foo: number; baz: number; }' is not assignable to type '{ foo: number; }'.
Object literal may only specify known properties, and 'baz' does not exist in type '{ foo: number; }'.
(property) baz: number

  fallthroughCasesInSwitchStatement(a: number) {
    switch (a) {
      case 0:
        break;

      case 1:
        a += 1;

      case 2:
        a += 2;
        break;
    }
  }

{
    "compilerOptions": {
        "noFallthroughCasesInSwitch": true
    }
}

  indexingObjectsLackingIndexSignatures() {
    const x = { a: 0 };
    x["a"] = 1; // ok
    x["b"] = 1; // Error, type '{ a: number; }' has no index signature.
  }

{
    "compilerOptions": {
        "suppressImplicitAnyIndexErrors": false
    }
}

[ts] Element implicitly has an 'any' type because type '{ a: number; }' has no index signature.

{
    "compilerOptions": {
        "noImplicitAny": true
    }
}

  noImplicitAny(args) { // Error: Parameter 'args' implicitly has an 'any' type.
    console.log(args);
  }

  noImplicitAnyArgs(args: string[]) { // ok with the type information
    console.log(args);
  }

This preview includes more than 50 bug fixes and functional enhancements. You can query our issue tracker for the full list of issues fixed in Preview 4, as well as for the issues fixed in Preview 3, and Preview 2. 

background-clip is one of those properties I've known about for years, but rarely used. Maybe just a couple of times as part of a solution to a Stack Overflow question. Until last year, when I started creating my huge collection of sliders. Some of the designs I chose to reproduce were a bit more complex and I only had one element available per slider, which happened to be an input element, meaning that I couldn't even use pseudo-elements on it. Even though that does work in certain browsers, the fact that it works is actually a bug and I didn't want to rely on that. All this meant I ended up using backgrounds, borders, and shadows a lot. I also learned a lot from doing that and this article shares some of those lessons.  

Resume Management project with React18, ASP.NET Core7 WebAPI, TypeScript and Entity Framework Core
In this video, we will create a Fullstack Resume Management project using React18, ASP.NET Core WebAPI  (.NET 7),TypeScript and Entity Framework Core. The focus of this project is to show you how you can build a Fullstack project from 0 to 100 and build a simple CRUD application with ASP.NET Core WebAPI .
 

Pet Store Fullstack project with React18, ASP.NET Core7 WebAPI, TypeScript and Entity Framework Core
In this video, we will create a Fullstack Pet Store project using React18, ASP.NET Core WebAPI  (.NET 7),TypeScript and Entity Framework Core. The focus of this project is to show you how you can build a Fullstack project from 0 to 100 and build a simple CRUD application with ASP.NET Core WebAPI . 

Deno is a new runtime for executing JavaScript and TypeScript outside of the web browser. 

Why TypeScript is the best way to write Front-end in 2019 

Issues fixed in Visual Studio 2019 version 16.0.4

• Attach to iis prompt to attach multiple times.
• WPF applications broken after FW 4.8 update.
• installing typescript 3.3 disables version 2.2 compilation.
• Unable to attach debugger when attaching multiple startup projects on Visual Studio 2019.
• Known issue: Application tab of VB project property pages is broken when isntalling the .NET Framework 4.8 Developer Pack.
• Visual Studio extensions may fail to install attempting to overwrite core NuGet files.
• microsoft.diagnosticshub.dotnetobjectalloc.vsix missing from offline installer.

Security Advisory Notices

CVE-2019-0727 Diagnostics Hub Standard Collector Service Elevation of Privilege Vulnerability

An elevation of privilege vulnerability exists when the Diagnostics Hub Standard Collector Service improperly performs certain file operations. An attacker who successfully exploited this vulnerability could delete files in arbitrary locations. To exploit this vulnerability, an attacker would require unprivileged access to a vulnerable system. The security update addresses the vulnerability by securing locations the Diagnostics Hub Standard Collector performs file operations in. 

templates for HTML emails “making sure it is semantic, functional, accessible and meeting user expectations. Consistency between email clients and pixel perfect design are also important but always secondary.”