test-repo/changelog_unreleased/javascript/14314.md

[BREAKING] Remove Flow syntax support from babel parser (#14314 by @fisker, @thorn0)

For historical reasons, Prettier used to recognize Flow syntax in JS files when the parser option was set to babel even if the file didn't include the @flow pragma. This support was limited and bad for performance, so it has been removed in Prettier main. Prettier with the babel parser still automatically switches to the Flow syntax if it finds the @flow pragma or the file has the .js.flow extension.