---
phase: 01-foundation
plan: "04"
subsystem: store
tags: [typescript, react, useReducer, context, tdd, vitest, security]

# Dependency graph
requires:
  - 01-02 (BackendType from registry.ts, reducer.test.ts TDD stub)
  - 01-03 (completes schemas layer alongside store layer)
provides:
  - WizardState interface, WizardAction union type, INITIAL_STATE constant (src/store/types.ts)
  - Pure wizardReducer function (src/store/reducer.ts)
  - WizardContext, WizardProvider, useWizard hook (src/store/context.tsx)
  - App.tsx wired with WizardProvider as root context
affects:
  - Phase 2 (script generator reads WizardState.remote and WizardState.deployment)
  - Phase 3 (form components call useWizard to read/write state)

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Pure reducer pattern: wizardReducer has no side effects, no localStorage, no async"
    - "useReducer + Context API: centralized state without external state library"
    - "Null-guarded hook: useWizard throws if used outside WizardProvider"
    - "SECU-03 enforcement via comment contract in types.ts — in-memory only, tab close clears credentials"

key-files:
  created:
    - src/store/types.ts
    - src/store/reducer.ts
    - src/store/context.tsx
  modified:
    - src/App.tsx

key-decisions:
  - "useReducer + Context API chosen over external state library — zero dependencies, sufficient for 4-step wizard"
  - "useWizard throws on missing provider — fail fast prevents silent undefined state propagation"
  - "INITIAL_STATE.deployment.scriptTargets defaults to both ['intune', 'rmm'] — users deselect rather than discover"

requirements-completed: []

# Metrics
duration: 2min
completed: 2026-03-26
---

# Phase 01 Plan 04: WizardState Store Summary

**Pure reducer + React Context store for wizard state: types, wizardReducer (8 tests green), WizardProvider, and useWizard hook wired into App.tsx with zero browser storage access (SECU-03)**

## Performance

- **Duration:** ~2 min
- **Started:** 2026-03-26T10:23:09Z
- **Completed:** 2026-03-26T10:24:49Z
- **Tasks:** 2
- **Files modified:** 4

## Accomplishments

- `src/store/types.ts` created: `WizardState` interface with `remote` (name, backendType, params) and `deployment` (includeInstall, configPath, scriptTargets) sub-objects; `WizardAction` union type (6 action variants); `INITIAL_STATE` constant; re-exports `BackendType` from registry for single-import convenience
- `src/store/reducer.ts` created: pure `wizardReducer` handling all 6 action types via spread operators — no mutation, no side effects
- All 8 tests in `src/store/reducer.test.ts` pass GREEN (covering INIT, SET_STEP, SET_BACKEND_TYPE, SET_REMOTE_NAME, SET_REMOTE_PARAMS, SET_DEPLOYMENT, RESET, purity check)
- `src/store/context.tsx` created: `WizardProvider` (useReducer wrapper), `useWizard` hook (throws on missing provider), typed `WizardContextValue` interface
- `src/App.tsx` updated: content wrapped in `<WizardProvider>` — all future components can call `useWizard()` without prop drilling
- Full test suite: 23 tests pass across 3 files (registry.test.ts, schemas/index.test.ts, store/reducer.test.ts)
- `npm run build` exits 0 — no TypeScript errors
- SECU-03 verified: no `localStorage`, `sessionStorage`, or `IndexedDB` method calls in any store file

## Task Commits

Each task was committed atomically:

1. **Task 1: Implement WizardState types and pure reducer** - `3fade79` (feat)
2. **Task 2: Create WizardContext provider and wire into App** - `2eef722` (feat)

**Plan metadata:** _(committed after SUMMARY.md — see final commit)_

## Files Created/Modified

- `src/store/types.ts` — WizardState, WizardAction, INITIAL_STATE, re-exports BackendType
- `src/store/reducer.ts` — pure wizardReducer function (8 tests)
- `src/store/context.tsx` — WizardContext, WizardProvider, useWizard hook
- `src/App.tsx` — wrapped with WizardProvider

## Decisions Made

- `useReducer + Context API` chosen over Zustand/Redux — zero external dependencies, sufficient for a 4-step linear wizard
- `useWizard()` throws `Error('useWizard must be used inside <WizardProvider>')` on missing provider — fail fast, no silent undefined propagation
- `scriptTargets` defaults to `['intune', 'rmm']` (both selected) — users opt-out rather than opt-in, reducing the chance of incomplete output

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None. TDD RED→GREEN flow was clean. Build passed on first attempt.

## User Setup Required

None.

## Next Phase Readiness

- All store types exported from `src/store/types.ts` — Phase 3 form components import `WizardState`, `WizardAction`, `useWizard`
- `src/store/context.tsx` exports `useWizard` — components call `const { state, dispatch } = useWizard()` to read/write wizard data
- Phase 2 script generator reads `state.remote.backendType`, `state.remote.name`, `state.remote.params` and `state.deployment` for config/script output
- Foundation layer complete: registry + schemas + store all implemented and tested (23 tests green)

---
*Phase: 01-foundation*
*Completed: 2026-03-26*

## Self-Check: PASSED

- src/store/types.ts: FOUND
- src/store/reducer.ts: FOUND
- src/store/context.tsx: FOUND
- src/App.tsx: FOUND
- .planning/phases/01-foundation/01-04-SUMMARY.md: FOUND
- Commit 3fade79 (Task 1): FOUND
- Commit 2eef722 (Task 2): FOUND