# Implementation Plan: Compare Job Legacy Drift Path Cleanup

**Branch**: `205-compare-job-cleanup` | **Date**: 2026-04-14 | **Spec**: `/Users/ahmeddarrazi/Documents/projects/TenantAtlas/specs/205-compare-job-cleanup/spec.md`
**Input**: Feature specification from `/Users/ahmeddarrazi/Documents/projects/TenantAtlas/specs/205-compare-job-cleanup/spec.md`

**Note**: This plan treats Spec 205 as a mechanical closure cleanup. It removes only the dead pre-strategy drift-compute path from `CompareBaselineToTenantJob`, keeps the current strategy-driven compare execution unchanged, and uses focused regression plus guard coverage to prove no behavior drift.

## Summary

Delete `computeDrift()` and its exclusive helper cluster from `CompareBaselineToTenantJob`, preserve the existing `CompareStrategyRegistry` -> `IntuneCompareStrategy` execution path, remove dead imports and misleading internal descriptions that survive only because of the retained legacy block, and verify unchanged behavior through focused compare execution, finding, and guard tests.

## Technical Context

**Language/Version**: PHP 8.4.15  
**Primary Dependencies**: Laravel 12, Filament v5, Livewire v4, Pest v4, Laravel Sail, existing `BaselineCompareService`, `CompareBaselineToTenantJob`, `CompareStrategyRegistry`, `IntuneCompareStrategy`, `CurrentStateHashResolver`, and current finding lifecycle services  
**Storage**: PostgreSQL via existing baseline snapshots, baseline snapshot items, inventory items, `operation_runs`, findings, and current run-context JSON; no new storage planned  
**Testing**: Pest feature and guard tests run through Laravel Sail, with focused compare execution and file-content guard coverage  
**Target Platform**: Laravel web application under `apps/platform` with queue-backed compare execution in Sail/Docker  
**Project Type**: web application in a monorepo (`apps/platform` plus `apps/website`)  
**Performance Goals**: Preserve current compare start latency and compare job throughput, add no new remote calls or DB writes, and keep operator-facing compare and monitoring surfaces behaviorally unchanged  
**Constraints**: No behavior change, no new abstraction or persistence, no operator-facing surface changes, no `OperationRun` lifecycle changes, and keep the PR mechanically small and reviewable  
**Scale/Scope**: One queued compare job, one compare start service boundary, one active strategy registry, one active Intune strategy, existing finding and run writers, and a small focused regression slice

## Constitution Check

*GATE: Passed before Phase 0 research. Re-checked after Phase 1 design and still passing because the feature removes code without altering scope, auth, persistence, or UI contracts.*

| Principle | Pre-Research | Post-Design | Notes |
|-----------|--------------|-------------|-------|
| Inventory-first / snapshots-second | PASS | PASS | Compare still reads existing workspace baseline snapshots and inventory-backed current state; no new compare truth is introduced. |
| Read/write separation | PASS | PASS | Existing compare runs still write only current run, finding, and audit truth; the cleanup adds no new write path. |
| Graph contract path | PASS | PASS | No new Microsoft Graph path or contract is introduced. |
| Deterministic capabilities | PASS | PASS | Existing strategy selection and capability behavior remain unchanged because the registry and strategy classes stay intact. |
| Workspace + tenant isolation | PASS | PASS | No workspace, tenant, or route-scope behavior changes are planned. |
| RBAC-UX authorization semantics | PASS | PASS | No authorization rules, capability checks, or cross-plane behavior are changed. |
| Run observability / Ops-UX | PASS | PASS | Existing `baseline_compare` run creation, summary counts, and completion semantics remain authoritative and unchanged. |
| Data minimization | PASS | PASS | No new persisted diagnostics or helper truth is added; dead internal code is removed instead. |
| Proportionality / anti-bloat | PASS | PASS | The feature deletes an obsolete path and introduces no new structure. |
| No premature abstraction | PASS | PASS | No new factory, resolver, registry, strategy, or support layer is introduced. |
| Persisted truth / behavioral state | PASS | PASS | No new table, stored artifact, status family, or reason family is added. |
| UI semantics / few layers | PASS | PASS | No new presentation layer or surface behavior is introduced. |
| Filament v5 / Livewire v4 compliance | PASS | PASS | No Filament or Livewire API changes are part of this cleanup. |
| Provider registration location | PASS | PASS | No panel or provider change is required; Laravel 11+ provider registration remains in `bootstrap/providers.php`. |
| Global search hard rule | PASS | PASS | No searchable resource or search behavior is touched. |
| Destructive action safety | PASS | PASS | No destructive action is added or changed. |
| Asset strategy | PASS | PASS | No new assets are introduced and existing `filament:assets` deployment behavior remains unchanged. |

## Filament-Specific Compliance Notes

- **Livewire v4.0+ compliance**: Unchanged. The feature touches no Filament surface or Livewire component and does not introduce legacy APIs.
- **Provider registration location**: Unchanged. If any panel/provider review is needed later, Laravel 11+ still requires `bootstrap/providers.php`.
- **Global search**: No globally searchable resource is added or changed.
- **Destructive actions**: No destructive action is introduced; existing confirmation and authorization rules remain untouched.
- **Asset strategy**: No new panel or shared assets are required. Deployment handling of `cd apps/platform && php artisan filament:assets` remains unchanged.
- **Testing plan**: Focus on the required compare cleanup pack only: compare execution and findings regressions, gap and reason-code coverage, `Spec116OneEngineGuardTest`, `Spec118NoLegacyBaselineDriftGuardTest`, existing `OperationRun` and summary-count guards, and the enqueue-path matrix action regression. No new page, widget, relation manager, or action surface coverage is required.

## Phase 0 Research

Research outcomes are captured in `/Users/ahmeddarrazi/Documents/projects/TenantAtlas/specs/205-compare-job-cleanup/research.md`.

Key decisions:

- Treat the current `CompareStrategyRegistry` -> `IntuneCompareStrategy` execution path as the only supported compare engine.
- Delete the dead `computeDrift()` cluster rather than retaining it as deprecated or archived code.
- Preserve `CompareSubjectResult`, finding upsert, summary aggregation, gap handling, and run completion semantics exactly as they currently operate through the live strategy path.
- Use one focused compare pack covering execution fidelity, finding lifecycle, gap and reason outcomes, `OperationRun` lifecycle guards, summary-count guards, and the no-legacy orchestration guard as the minimum reliable regression slice.
- Keep the contract artifact logical and internal, documenting invariants of the unchanged execution boundary instead of inventing a new external API.

## Phase 1 Design

Design artifacts are created under `/Users/ahmeddarrazi/Documents/projects/TenantAtlas/specs/205-compare-job-cleanup/`:

- `research.md`: cleanup decisions, rationale, and rejected alternatives
- `data-model.md`: existing persisted truth and internal compare contracts preserved by the cleanup
- `contracts/compare-job-legacy-drift-cleanup.logical.openapi.yaml`: logical internal contract for the unchanged compare start and execution boundaries plus the no-legacy guard invariant
- `quickstart.md`: implementation and verification order for the cleanup

Design decisions:

- `CompareBaselineToTenantJob` remains the compare execution entry point, but only the live orchestration methods stay after cleanup.
- `CompareStrategyRegistry`, `IntuneCompareStrategy`, `CompareStrategySelection`, `CompareOrchestrationContext`, `CompareSubjectResult`, and `CompareFindingCandidate` remain reused unchanged.
- Existing persisted truth in baseline snapshots, inventory, findings, and `operation_runs` remains authoritative; no migration or compatibility layer is added.
- Guard coverage remains the explicit enforcement point preventing legacy drift computation from re-entering the orchestration file.
- Existing `OperationRun` lifecycle and summary-count guards remain part of the required verification surface because the cleanup still edits the compare executor.
- No route, UI, RBAC, or `OperationRun` design change is planned.

## Project Structure

### Documentation (this feature)

```text
specs/205-compare-job-cleanup/
├── plan.md
├── research.md
├── data-model.md
├── quickstart.md
├── spec.md
├── contracts/
│   └── compare-job-legacy-drift-cleanup.logical.openapi.yaml
└── checklists/
    └── requirements.md
```

### Source Code (repository root)

```text
apps/platform/
├── app/
│   ├── Jobs/
│   │   └── CompareBaselineToTenantJob.php
│   ├── Services/
│   │   └── Baselines/
│   │       ├── BaselineCompareService.php
│   │       ├── CurrentStateHashResolver.php
│   │       └── Evidence/
│   └── Support/
│       └── Baselines/
│           └── Compare/
│               ├── CompareStrategyRegistry.php
│               ├── CompareStrategySelection.php
│               ├── CompareSubjectResult.php
│               ├── CompareFindingCandidate.php
│               └── IntuneCompareStrategy.php
└── tests/
    ├── Feature/
    │   ├── BaselineDriftEngine/
    │   │   └── FindingFidelityTest.php
    │   ├── Baselines/
    │   │   ├── BaselineCompareFindingsTest.php
    │   │   ├── BaselineCompareGapClassificationTest.php
    │   │   ├── BaselineCompareWhyNoFindingsReasonCodeTest.php
    │   │   └── BaselineCompareMatrixCompareAllActionTest.php
    │   └── Guards/
    │       ├── Spec116OneEngineGuardTest.php
    │       ├── Spec118NoLegacyBaselineDriftGuardTest.php
    │       └── OperationLifecycleOpsUxGuardTest.php
    │   ├── Operations/
    │   │   └── BaselineOperationRunGuardTest.php
    │   └── OpsUx/
    │       ├── OperationSummaryKeysSpecTest.php
    │       └── SummaryCountsWhitelistTest.php
```

**Structure Decision**: Keep the cleanup inside the existing compare orchestration file and current compare regression surfaces. No new namespace, support layer, or package structure is introduced.

## Complexity Tracking

No constitution exception or complexity justification is required. Spec 205 removes an obsolete implementation branch and introduces no new persistence, abstraction, state family, or semantic framework.

## Proportionality Review

Not triggered. This feature introduces no new enum or status family, DTO or presenter layer, persisted artifact, interface or registry, or cross-domain taxonomy.

## Implementation Strategy

### Phase A - Confirm dead call graph

- Confirm that `handle()` no longer reaches `computeDrift()` or its candidate helper cluster.
- Confirm that the live path still runs through strategy selection, strategy resolution, `strategy->compare(...)`, normalization, finding upsert, and run completion.
- Record the final helper delete list before editing to avoid removing shared orchestration methods.

### Phase B - Delete the legacy drift cluster

- Remove `computeDrift()` and every helper method used exclusively by that legacy path.
- Remove only the imports, comments, and internal descriptions that become dead because of the delete.
- Keep shared orchestration helpers such as evidence resolution, result normalization, summary aggregation, gap merging, and finding lifecycle methods untouched.

### Phase C - Preserve the live orchestration contract

- Leave `BaselineCompareService`, `CompareStrategyRegistry`, and `IntuneCompareStrategy` behavior unchanged unless a direct compile or test failure requires a minimal follow-up.
- Preserve the existing `baseline_compare` run context shape, summary count rules, gap handling, reason translation, and finding lifecycle semantics.
- Avoid any naming sweep, contract redesign, or opportunistic cleanup outside the dead cluster.

### Phase D - Guard and regression verification

- Keep or tighten the existing no-legacy guard so the removed path cannot silently re-enter the orchestration file.
- Run focused compare execution, gap and reason-code regression, and `OperationRun` lifecycle and summary-count guard tests to prove the delete is mechanically safe.
- Format the touched PHP files with Pint after the cleanup is implemented.

## Risk Assessment

| Risk | Impact | Likelihood | Mitigation |
|------|--------|------------|------------|
| A supposedly dead helper is still used by the live orchestration path | High | Medium | Confirm call sites before deletion and keep the initial regression pack focused on execution, findings, gap and reason outcomes, and run-lifecycle guards. |
| The cleanup grows into a broader refactor while the job file is open | Medium | Medium | Constrain edits to dead methods, direct import fallout, and guard or test changes required by the delete. |
| Existing guard tests are too weak or too token-specific to prevent reintroduction | Medium | Medium | Reuse `Spec118NoLegacyBaselineDriftGuardTest` and extend it with the removed method names only if the current assertions do not cover the dead-path cluster clearly enough. |
| A regression test depends on deleted internal structure rather than behavior | Medium | Low | Update such tests to assert live compare outcomes and orchestration invariants rather than private helper presence. |

## Test Strategy

- Run `tests/Feature/BaselineDriftEngine/FindingFidelityTest.php` as the primary execution and evidence-fidelity regression slice.
- Run `tests/Feature/Baselines/BaselineCompareFindingsTest.php` to protect finding generation, recurrence, summary counts, and run completion outcomes.
- Run `tests/Feature/Baselines/BaselineCompareGapClassificationTest.php` and `tests/Feature/Baselines/BaselineCompareWhyNoFindingsReasonCodeTest.php` to protect gap handling, warning outcomes, and reason translation behavior.
- Run `tests/Feature/Guards/Spec116OneEngineGuardTest.php` to keep the one-engine orchestration invariant explicit while the dead fallback cluster is removed.
- Run `tests/Feature/Guards/OperationLifecycleOpsUxGuardTest.php`, `tests/Feature/Operations/BaselineOperationRunGuardTest.php`, `tests/Feature/OpsUx/OperationSummaryKeysSpecTest.php`, and `tests/Feature/OpsUx/SummaryCountsWhitelistTest.php` to keep `OperationRun` lifecycle and summary-count guarantees intact.
- Run `tests/Feature/Guards/Spec118NoLegacyBaselineDriftGuardTest.php` to lock the orchestration boundary against legacy drift helper re-entry.
- Run `tests/Feature/Baselines/BaselineCompareMatrixCompareAllActionTest.php` as the required enqueue-path regression slice for the focused cleanup pack.
- Run `cd apps/platform && ./vendor/bin/sail bin pint --dirty --format agent` after the code change.