Struct IdentityMigration 

pub struct IdentityMigration<W> { /* private fields */ }

A no-op StateMigration for workflows whose state schema did not change between two BDEW format versions.

Use this when the FV transition only added new optional AHB rules, segment cardinality changes, or code-list entries — no field was renamed, removed, or made mandatory. The migrated snapshot repoints workflow_id to the new FV while keeping the state value identical.

Example

use mako_engine::migration::IdentityMigration;
use mako_engine::version::WorkflowId;
use mako_gpke::lf_anmeldung::{GpkeLfAnmeldungWorkflow, WORKFLOW_NAME};

let migration = IdentityMigration::<GpkeLfAnmeldungWorkflow>::new(
    WorkflowId::new(WORKFLOW_NAME, "FV2025-10-01"),
    WorkflowId::new(WORKFLOW_NAME, "FV2026-10-01"),
);

Implementations

impl<W: Workflow> IdentityMigration<W>

pub fn new(source: WorkflowId, target: WorkflowId) -> Self

Construct a new identity migration between two format versions.

Trait Implementations

impl<W> StateMigration for IdentityMigration<W>

where W: Workflow + Send + Sync + 'static, W::State: Clone,

type FromWorkflow = W

The old workflow definition whose events are stored in matched streams.

type ToWorkflow = W

The new workflow definition that continues execution after migration.

fn source_workflow_id(&self) -> &WorkflowId

The WorkflowId (name + old BDEW FV) that identifies streams to migrate.

fn target_workflow_id(&self) -> &WorkflowId

The WorkflowId (name + new BDEW FV) stamped into the migrated snapshot.

fn migrate(&self, state: W::State) -> Result<W::State, String>

Map the fully-replayed old state to the new state type.