def Record.upgrade

bend-kit-migrate@0.3.0.0 · migrate.bend:180

import Base

180# Any version to v3, with what the chain dropped.
181def Record.upgrade(r: Record) -> V3 & Dropped:
182  match r:
183    case R1{x}:
184      V2.up(V1.up(x))
185    case R2{x}:
186      V2.up(x)
187    case R3{x}:
188      (x, Dropped{None{}})