---
id: EANCH-WP-0003
type: workplan
title: "Non-PDF selectors: HTML/Markdown DOM range + structural anchoring"
domain: infotech
repo: evidence-anchor
status: proposed
owner: codex
topic_slug: citation_evidence_mvp
created: "2026-07-08"
updated: "2026-07-08"
spec_refs:
  - INTENT.md
  - SCOPE.md
  - ../citation-evidence/wiki/SharedContracts.md
  - ../citation-evidence/docs/decisions/ADR-0006-selector-ownership-split.md
---

# EANCH-WP-0003 — Non-PDF Selectors (HTML / Markdown)

## Goal

Extend anchoring beyond PDFs to non-paginated documents (HTML, Markdown),
delivering the `DomRangeSelector` and `StructuralSelector` concepts that
`INTENT.md` names but the MVP left as `never`. The extracted package already
models format-neutral resolution (`DocumentViewerAdapter`, canonical-text
selectors); this workplan fills in the DOM branch of `SelectionCapture` and a
concrete HTML/Markdown viewer adapter.

Depends on the extraction (`EANCH-WP-0001`) being complete. Independent of the
resolution-hardening track (`EANCH-WP-0002`) except where both touch the shared
enum — coordinate contract changes in the umbrella wiki first.

## Background

- `src/types.ts`: `DomSelectionCapture = never` (reserved) — the capture union
  only has a PDF branch today.
- `citation-engine` shared selector types already declare `DomRangeSelector`
  and `StructuralSelector` as `never` placeholders; promoting them is a
  shared-contract change and must land in `citation-engine` first (ADR-0006:
  selector *types* live in engine).

## Task Breakdown

## T01 — Contract: promote DomRange/Structural selector types in citation-engine

```task
id: EANCH-WP-0003-T01
status: todo
priority: high
```

Define the real `DomRangeSelector` and `StructuralSelector` shapes (DOM path +
range offsets; heading/section/block/AST path) in `citation-engine`'s shared
selector module, plus the `DomSelectionCapture` payload contract in the wiki.
Land this in the engine + `SharedContracts.md` before writing anchor behavior.

## T02 — Selector creation from a DOM/Markdown selection

```task
id: EANCH-WP-0003-T02
status: todo
priority: high
depends_on: [T01]
```

Implement `createSelectors` for the DOM branch: build TextQuote + TextPosition
(against canonical text) plus DomRange + Structural selectors from a captured
DOM selection. Add unit tests mirroring the PDF create tests.

## T03 — Resolution for non-paginated documents

```task
id: EANCH-WP-0003-T03
status: todo
priority: high
depends_on: [T02]
```

Extend `resolveSelectors` to resolve DomRange/Structural selectors and rank
them in the confidence ladder alongside the existing text selectors, keeping
paginated (PDF) and non-paginated resolution on shared concepts. Tests for
re-render stability (structural fallback when offsets shift).

## T04 — HTML/Markdown viewer adapter

```task
id: EANCH-WP-0003-T04
status: todo
priority: medium
depends_on: [T03]
```

Add a `DocumentViewerAdapter` implementation for rendered HTML/Markdown
(selection capture, scroll-to-target, highlight render), behind a subpath
export analogous to `evidence-anchor/pdf`, with viewer-specific deps confined
to that boundary.

## T05 — Verification + close-out

```task
id: EANCH-WP-0003-T05
status: todo
priority: high
depends_on: [T04]
```

Package green (`pnpm test`/`typecheck`/`lint`); engine contract change verified
in `citation-engine`; any umbrella consumer green; `fix-consistency` clean;
progress note.