Typescript WTF Moments 9: Evolving Empty Array Type

const a = false || [] // ^? const b = [] // ^? function c() { // ^? return [] } const d = c() // ^? 

let b = false || [] // ^? const a:number[] = b const c:string[] = b b = a // error as expected b = c // expect as expected let b1 = [] // ^? const a1:number[] = b1 // did not expect error but error const c1:string[] = b1 // did not expect error but error b1 = a1 b1 = c1 // with type annotation let b2:any[] = [] // ^? const a2:number[] = b2 const c2:string[] = b2 b2 = a2 b2 = c2