test-repo/changelog_unreleased/graphql/12835.md

[BREAKING] Drop support for "comma separated interfaces" syntax (#12835 by @fisker)

# Input
type Type1 implements A, B {a: a}

# Prettier stable
type Type1 implements A, B {
  a: a
}

# Prettier main
SyntaxError: Syntax Error: Unexpected Name "B". (1:26)
> 1 | type Type1 implements A, B {a: a}