7.9.0 Released: Smaller preset-env output, Typescript 3.8 support and a new JSX transform
While preparing the Babel 8.0.0 release (in the next months), we just finished working on a new minor release which includes updates related to @babel/preset-env
, TypeScript 3.8, Flow, and JSX!
A few months ago, Jason Miller started working on @babel/preset-modules
: an experiment to greatly reduce bundle sizes when using the module
/nomodule
pattern. We are excited to announce that its functionality has now been merged into @babel/preset-env
! This means that its optimizations can be applied to all preset-env
targets values, without a separate preset.
Note: These optimizations will be enabled by default in Babel 8. They can be manually enabled in Babel 7.9 by passing in the option { bugfixes: true }
to preset-env
.
This release also has full support for TypeScript 3.8, which introduced explicit type-only imports and exports (i.e. export type { foo }
), and for Flow 0.120, which introduced the declare
modifier for class fields (i.e. class C { declare foo: string }
).
We also worked with the React team to provide a new JSX transform, which will make it possible for React and React-like libraries to further optimize the creation of JSX elements with the addition of the jsx
function vs. React.createElement
.
Lastly, @babel/parser
now supports an additional ECMAScript proposal: Record & Tuple. Please note that this is only parser support, and the transforms are still being worked on.
You can read the whole changelog on GitHub.