# Visual Graph Diff with Change Highlights

## Module
Web

## Status
VERIFIED

## Description
Full graph diff component with change type highlighting (added/removed/changed), layout engine, split-view, connected element detection, and Storybook stories. Originally marked TODO in advisory but now implemented.

## Implementation Details
- **Feature directory**: `src/Web/StellaOps.Web/src/app/shared/components/graph-diff/`
- **Components**:
  - `graph-diff` (`src/Web/StellaOps.Web/src/app/shared/components/graph-diff/graph-diff.component.ts`)
  - `graph-split-view` (`src/Web/StellaOps.Web/src/app/shared/components/graph-diff/graph-split-view.component.ts`)
- **Engine/Models**:
  - `src/Web/StellaOps.Web/src/app/shared/components/graph-diff/graph-diff-engine.ts`
  - `src/Web/StellaOps.Web/src/app/shared/components/graph-diff/graph-diff.models.ts`
- **Behavior coverage**:
  - `src/Web/StellaOps.Web/src/tests/graph/visual-graph-diff-with-change-highlights.behavior.spec.ts`
- **Source**: Feature matrix scan

## E2E Test Plan
- **Setup**:
  - [ ] Log in with a user that has appropriate permissions
  - [ ] Navigate to the relevant page/section where this feature appears
  - [ ] Ensure test data exists (scanned artifacts, SBOM data, or seed data as needed)
- **Core verification**:
  - [ ] Verify side-by-side comparison view renders correctly with two versions
  - [ ] Verify additions, removals, and changes are visually highlighted
  - [ ] Verify diff data matches the expected delta between versions
- **Edge cases**:
  - [ ] Verify graceful handling when backend API is unavailable (error state)
  - [ ] Verify responsive layout at different viewport sizes
  - [ ] Verify accessibility (keyboard navigation, screen reader labels, ARIA attributes)

## Verification
- Run ID: `docs/qa/feature-checks/runs/web/visual-graph-diff-with-change-highlights/run-001/`
- Date (UTC): 2026-02-11
- Tier 0: PASS (graph-diff component, split-view component, engine/models, and supported behavior harness paths/symbols verified).
- Tier 1: PASS (`npm run test` focused + regression include suite: 40 files / 184 tests; `npm run build` passed with baseline warnings only).
- Tier 2: PASS (change-highlight rendering, connected-element emphasis, split/unified interaction behavior, and deterministic ordering semantics verified via Angular behavior harness).