Your Choice JavaScript News

TypeScript News Saturday, May 12 Http debugging proxy, Product hunt, Template-driven forms & more…

What’s new?

  • As a web developer, I use a lot of tools (new & old), utilities & some tips from my discovery and from lots of people around (twitter, product hunt etc,).
  • Today I want to share all of apps & tools I use for web development.

Tags: http debugging proxy, invaluable tool, product hunt, sure check, web developer

  • Here it is in action: (See on StackBlitz at app component doesn’t need to do much since the form fields and validators are defined in the template when using Angular template-driven forms.
  • The component defines a model object which is bound to the form fields in the template in order to give you access to the data entered into the form from the app component.
  • The app component template contains all the html markup for displaying the example registration form in your browser.
  • The form input fields use the directive to bind to properties of the object in the app component.
  • Validation messages are displayed only after the user attempts to submit the form for the first time, this is controlled with the property of the Angular template variable.

Tags: template-driven forms, Angular template-driven forms, app component, Angular template variable, template-driven forms example


  • What this means is that while no one else outside of the Class can access the private properties or Class A, one instance of class A can actually access the private properties of another instance of Class A.
  • Given this private property accessibility, I wanted to see if Static method on a Class could access the private properties of a Class instance.
  • Specifically, I wanted to see if Static factory methods could invoke a private constructor, forcing all Class instantiation to go through the static methods.
  • To test this, I created a Person class with a private constructor and several static factory methods: – – As you can see, the Person class has a private constructor which takes three name components (first, middle, and last).
  • And, if we run this code through ts-node, we get the following console output: – – As you can see, the Static factory methods on the Person class were all able to access and invoke the private class constructor.

Tags: class, private constructor, Unreachable code, new Person, static methods

  • Released in March 2018, Version 2.8 of TypeScript addsa conditional types construct for modeling.
  • In strict mode, any function type that does not originate from a method has its parameters compared contravariantly, said Microsofts Daniel Rosenwasser, program manager for TypeScript.
  • Another key set of new features in TypeScript 2.6 covers error suppression comments, which are introduced via comments.
  • Microsoft has avoided error suppression in TypeScript because most cases where users asked for it could be solved through more accurate declaration files, or using a type assertion to , Rosenwasser said.
  • However, over time, we have seen two motivating examples, Rosenwasser added, migrating from JavaScript to TypeScript, and overcoming type checks that live in legacy code.

Tags: TypeScript, new type variable, new type aliases, respective length property, traditionally compared parameters