Migration — Setup (Pre-Migration Bootstrap)

Complete this once, before migrating an individual slice in ../SKILL.md → Recommended Order.

Step 1 — Install Dependencies

Use ../../../setup/SKILL.md → Installation workflow for package/peer installation and explicit skill installation. Select the Svelte bundle for this existing app; do not repeat greenfield first-slice creation during migration. That canonical setup owner links the installation, refresh/collision, cleanup, rollback/uninstall ordering, and maintainer workflow in @themislib/themis/docs/INSTALLATION.md.

Step 2 — Import the Package Runtime

Use the npm package directly; do not copy package sources into the app. Replace flat package-root, removed utilities-barrel, and source-shaped deep imports using ../../../core/import-boundaries/SKILL.md → Setup — the package export surface. Utility exports are explicit leaf subpaths, not wildcard domains. For Svelte Store imports use ../../store/SKILL.md → Correct import and class choice.

The package publishes compiled ESM files and TypeScript declarations from dist/, so application code should keep only app-specific store setup and slice files under src/lib/store/.

Step 3 — Create the Store and Bootstrap It

Create a single Store instance at module scope, add reducers to the constructor map, and register sagas as slices are migrated:

// src/lib/store/store.ts
import { Store } from "@themislib/themis/svelte-store";
import type { StoreState } from "@themislib/themis/types";

export const store = new Store({
  // counter: counterReducer,
});
export type AppState = StoreState<typeof store>;

For state inference, reserved internals, initialization, and disposal, follow ../../store/SKILL.md → Lifecycle rules. Apply ../../component-integration/SKILL.md → Root layout wiring to this configured Store. App sagas start explicitly, not automatically on init(); component mount/remount and imperative cancellation rules live in ../../store/SKILL.md → App saga lifetime. Do not copy a second lifecycle implementation here.

Step 4 — Start With Empty Registrations

Start with an empty app-owned reducer map and no app sagas. Add one reducer-map entry per migrated slice, plus explicit startup if it has a saga. Package-owned internals remain managed by Store; see ../../store/SKILL.md → Lifecycle rules.

After Setup

Return to ../SKILL.md → Recommended Order for the per-slice sequence, starting with the simplest isolated shared/domain store. Create slice/selectors/types and any needed saga using ../../../core/file-structure/SKILL.md → Setup — slice directory layout; then add the reducer and explicitly start its saga under the selected lifetime.

Setup Examples

Add each migrated slice through the reducer map

import { Store } from "@themislib/themis/svelte-store";
import type { StoreState } from "@themislib/themis/types";
import { counterReducer } from "$lib/store/slices/counter/counter-slice";

export const store = new Store({ counter: counterReducer });

export type AppState = StoreState<typeof store>;

Layout startup/cleanup examples are in ../../component-integration/SKILL.md → Root layout wiring; cancellation for services/tests receiving an already component-initialized Store is in ../../store/SKILL.md → App saga lifetime. Fresh standalone Svelte Store.init() is not supported. Keep init-before-run and reserved-name checks in that owner rather than duplicating lifecycle examples in the migration adapter.

5. Prove empty bootstrap has no app-owned registrations

import { Store } from "@themislib/themis/svelte-store";

const store = new Store({});
const composedReducers = store.getReducers();

export const emptyBootstrapEvidence = {
  reducerDomainsVisibleToApp: Object.keys(composedReducers).filter((key) => !key.startsWith("@internal_")),
};

getReducers() includes package-owned internal reducers even for new Store({}). Only the constructor input is app-owned; never register reserved keys manually.

Verification cues

• Empty-bootstrap evidence lists no app reducers until a slice is migrated.
• Each migrated reducer/saga has one registration owner; follow ../../store/SKILL.md → Verification cues for lifecycle checks and ../cleanup/SKILL.md → Final Checklist Per Slice before deleting legacy state.