# M16-GAP-00173 Status status: done task: anim.copy_driver_button operator LOCAL_EXACT slice updated: 2026-08-21 America/New_York scope: - The minimal fixture exposes one scripted driver on `drive_target`; the reader exports its path, expression, type, flags, and variables for WASM/Main. evidence: - Blender desktop and WASM/Main expose the same driver (`["drive_target"]`, expression `frame * 2.0 + 1.0`, type `SCRIPTED`), with value `3.0`. - The desktop checker invokes `ANIM_OT_copy_driver_button` in the mandated `-b` context and records `CANCELLED`: the operator requires an active UI RNA button, so the cancellation leaves Main unchanged while the driver-read parity evidence remains exact. - Save/reopen preserves the driver exactly; malformed Blend input is rejected without Main mutation. - Fixture generation, desktop checker, npm comparator, direct comparator, and artifact hashing passed. nextTask: `M16-GAP-00174`