TS1048
A rest parameter cannot have an initializer.
Since rest parameters will always be defined, even if no arguments are passed to the function or method, it doesn't make sense for them to have initializers:
function test(...args: number[] = [1, 2, 3]) {}Fix: Move out or destructure with initializers.
If you need the first few arguments to have initializers, you can move them out of the rest parameter or destructure the argument and default the first few members there.
function test(a = 1, b = 2, c = 3, ...rest: number[]) {}
// or
function test(...[a = 1, b = 2, c = 3, ...rest]: number[]) {}Related: TS1047