What’s new in TypeScript 3.3

TypeScript 3.3, now available in a release candidate, enables incremental file watching to speed up builds for composite projects

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TypeScript 3.3, the next upgrade to Microsoft’s typed superset of JavaScript, is available as a release candidate. The new version features incremental file watching for composite projects, producing quicker builds by re-checking and re-emitting only files that have changed, rather than performing a complete build of the entire project.

With TypeScript 3.3, the --build mode’s --watch flag now leverages incremental file watching, enabling significantly faster builds. In tests, the --build --watch functionality resulted in a 50 percent to 75 percent reduction in build times compared to the original --build --watch. TypeScript 3.3 also features improved behavior for calling union types.

Where to download the TypeScript 3.3 release candidate

You can download the release candidate through NuGet or via NPM:

npm install -g typescript@rc

Where to download TypeScript

You can download the production version of TypeScript through NuGet or via NPM. To get TypeScript via NPM, use the following command: npm install -g typescript.

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