TypeScript 2.7 Improves Type Inference
Written by Kay Ewbank   
Monday, 05 February 2018

There's a new version of TypeScript that has improvements including easier ECMAScript module interoperability, support for fixed length tuples, and smarter object literal inference.

TypeScript was developed by Microsoft ,and is a superset of JavaScript that builds on the ECMAScript standard and includes support for static types. Your TypeScript code then gets transformed into clean, runnable JavaScript.

The improvements to the new version start with stricter class property checks via a new strictness flag that makes sure that each instance property of a class gets set in the constructor body, or by a property initializer. Writing about the change on the MSDN blog, Daniel Rosenwasser, Program Manager on TypeScript says that:

"In a sense, it brings some of the definite assignment checks from variables to instance properties in classes."
 

The new version also strengthens the use of definite assignment assertions. These cater for situations where properties might be initialized indirectly, such as by a helper method or dependency injection library. You can use a definite assignment assertion to tell the type system that the property will definitely get assigned. In the past this was limited to class properties, but it can now be used on variable declarations.

The next change of interest is better interoperability for ECMAScript modules. The history of module formats in the JavaScript ecosystem means that there are several 'legacy' module formats such as those used by Babel, Webpack, and React Native, prior to ECMAScript modules being standardized in ES2015. The new version has a new compiler option that handles non-TypeScript module formats more intelligently.

Other improvements include cleaner output in --watch mode; better formatting of error messages when using the --pretty flag; support for fixed length tuples; and smarter object literal inference.

typescriptlogo

More Information

TypeScript on NuGet

TypeScript On GitHub

Related Articles

TypeScript 2.5 Adds Optional Catch Binding

TypeScript 2.4 Adds Dynamic Import Expressions  

TypeScript 2.3 Released

TypeScript 2.2 Adds More Code Actions

 

To be informed about new articles on I Programmer, sign up for our weekly newsletter, subscribe to the RSS feed and follow us on, Twitter, FacebookGoogle+ or Linkedin.

 

Banner


Facebook Dead Will Inevitably Outnumber Live Users
11/11/2018

Facebook has had a huge impact on the lives of its users, connecting individuals to their family and friends as never before. As time passes so do people, and there will come a point when more Faceboo [ ... ]



Visual Studio Code Python Gets Data Science Kit
12/11/2018

Microsoft has added new features to the Python extension for Visual Studio Code that can be used to work with data interactively in Visual Studio Code. The feature can be used to explore data sets or  [ ... ]


More News

 

Python

 



 

Comments




or email your comment to: comments@i-programmer.info