Recently flowtype released https://github.com/facebook/flow/releases/tag/v0.103.0

This includes facebook/flow@c18ee0d
which is a fix for facebook/flow#6875.

This new syntax is not supported by prettier.

Environments:

• Prettier Version: 1.18.2
• Running Prettier via: CLI
• Runtime: Node.js v10.15.0
• Operating System: macOS

Steps to reproduce:

function foo<T: any = number>(): any {}

Expected behavior:

src/foo.js 20ms

Actual behavior:

src/foo.js
[error] src/foo.js: SyntaxError: Unexpected token
[error] > 1 | function foo<T: any = number>(
[error]     |                     ^