refactor(ui): finalize diff row facade

.changeset/quiet-row-facade.md

@@ -0,0 +1,2 @@
+---
+---

docs/browser-review-seam-audit.md

@@ -109,13 +109,13 @@ whether a client needs more than that is Phase 5's first question.
   _Repaid (Phase 1 PR 2, model side)_: `splitLineCount`/`unifiedLineCount` carried on
   `ReviewFileV1` by `core/review/document.ts`; the browser consumes them in Phase 5.
 - **A8. Empty-diff explanation — 3 variants with different precedence.** Terminal
-  `renderRows.tsx` `diffMessage` (rename-pure first), web `ReviewStream.tsx` (binary first),
+  `plannedRowText.ts` `diffMessage` (rename-pure first), web `ReviewStream.tsx` (binary first),
   `staticDiffPager.ts` (extra cases). Same file can explain itself differently per client.
   Fix: `reviewEmptyDiffReason(file)` in core.
   _Repaid (Phase 1 PR 2)_: `reviewEmptyDiffReason` in `core/review/document.ts` with one canonical
   precedence — what the change _is_ outranks how it is stored (`rename-only` -> `binary` ->
   `too-large` -> `new-file` -> `deleted-file` -> `no-hunks`), the review stream's existing order.
-  `renderRows.tsx` and `staticDiffPager.ts` keep their own wording and share the reason; fixture
+  `plannedRowText.ts` and `staticDiffPager.ts` keep their own wording and share the reason; fixture
   `binary-rename-with-no-rows`. The static pager's own order put storage first, so a renamed
   binary or oversized rename now reports as a rename there too.
 - **A9. STML tag vocabulary — parse shared, tag semantics forked.** Terminal

docs/extension-architecture.md

@@ -130,8 +130,11 @@ text. `src/ui/diff/rowStyle.ts` resolves tones against the actual line
 background with the word-diff minimum-contrast guarantee.
 `src/ui/diff/CodeRowView.tsx` applies the transform through the cell painter,
 which keeps highlights out of `buildDiffSectionRowPlan`, its caches, and every
-geometry measurement: a highlight change is a repaint, never a re-plan. The
-static pager never runs extension code, so highlights are interactive-only.
+geometry measurement: a highlight change is a repaint, never a re-plan.
+`src/ui/diff/DiffRowView.tsx` remains only the memoized dispatch facade; raw-row
+adaptation there supports the public OpenTUI and extension current-line surfaces, while
+`src/ui/diff/cursorHighlight.ts` owns stable-key cursor matching. The static pager never
+runs extension code, so highlights are interactive-only.
 
 Agent attention marks (`hunk session highlight add` / `clear`) join this same
 pipeline rather than growing a second one: `useTerminalReview.ts` validates

src/opentui/HunkDiffBody.tsx

@@ -3,7 +3,7 @@ import { DEFAULT_TAB_WIDTH } from "../core/run/tabWidth";
 import { findMaxLineNumber } from "../ui/diff/codeColumns";
 import { buildSplitRows, buildStackRows } from "../ui/diff/diffRows";
 import { diffMessage, fitText } from "../ui/diff/plannedRowText";
-import { DiffRowView } from "../ui/diff/renderRows";
+import { DiffRowView } from "../ui/diff/DiffRowView";
 import { useHighlightedDiff } from "../ui/diff/useHighlightedDiff";
 import { resolveTheme } from "../ui/themes";
 import { toInternalDiffFile } from "./model";

src/ui/components/panes/DiffPane.tsx

@@ -27,7 +27,7 @@ import {
 } from "../../../core/review/state";
 import type { FileSourceStatus } from "../../diff/expandCollapsedRows";
 import type { ActiveAddNoteAffordance } from "../../diff/DiffSectionBody";
-import type { CursorHighlight } from "../../diff/renderRows";
+import type { CursorHighlight } from "../../diff/cursorHighlight";
 import { isNestedRowMouseAction } from "../../diff/rowMouseActions";
 import type { DraftReviewNote } from "../../lib/reviewNoteMapping";
 import {

src/ui/components/panes/DiffSection.tsx

@@ -4,7 +4,7 @@ import type { LayoutMode } from "../../../core/run/commandInputs";
 import type { UserNoteLineTarget } from "../../../core/liveComments";
 import type { FileSourceStatus } from "../../diff/expandCollapsedRows";
 import { DiffSectionBody, type ActiveAddNoteAffordance } from "../../diff/DiffSectionBody";
-import type { CursorHighlight } from "../../diff/renderRows";
+import type { CursorHighlight } from "../../diff/cursorHighlight";
 import type { VisibleBodyBounds } from "../../diff/rowWindowing";
 import type { DiffSectionGeometry } from "../../diff/diffSectionGeometry";
 import type { DiffSectionRowPlan } from "../../diff/diffSectionRowPlan";

src/ui/components/panes/FileView.tsx

@@ -9,7 +9,7 @@ import type {
 } from "../../../extension-api/types";
 import type { AppTheme } from "../../themes";
 import type { DiffSectionGeometry } from "../../diff/diffSectionGeometry";
-import { plannedRowMatchesCursor, type CursorHighlight } from "../../diff/renderRows";
+import { plannedRowMatchesCursor, type CursorHighlight } from "../../diff/cursorHighlight";
 import { cursorLineHighlightBg } from "../../diff/rowStyle";
 import { resolveVisibleRowIndexWindow, type VisibleBodyBounds } from "../../diff/rowWindowing";
 import { reviewRowId } from "../../lib/ids";

src/ui/components/ui-components.test.tsx

@@ -36,7 +36,7 @@ const { DiffFileHeaderRow } = await import("./panes/DiffFileHeaderRow");
 const { DiffSectionBody } = await import("../diff/DiffSectionBody");
 const { measurePlannedRenderedRowHeight, measureRenderedRowHeight } =
   await import("../diff/codeRowLayout");
-const { DiffRowView } = await import("../diff/renderRows");
+const { DiffRowView } = await import("../diff/DiffRowView");
 
 function createTestDiffFile(
   id: string,

src/ui/diff/CodeCellView.test.tsx

@@ -11,7 +11,7 @@ import {
 import { legacyPlannedDiffRow, planCodeRowLayout } from "./codeRowLayout";
 import type { DiffRow } from "./diffRows";
 import { lineHighlightPaintKey, type LineHighlightPaintIndex } from "./lineHighlightPaint";
-import { DiffRowView } from "./renderRows";
+import { DiffRowView } from "./DiffRowView";
 import { resolveTheme, withTransparentSurfaces } from "../themes";
 
 /** Capture one code-row component and always release its OpenTUI renderer. */

src/ui/diff/CodeRowView.tsx

@@ -1,6 +1,5 @@
 /** Mounts split and stack code rows from the canonical code-row layout and paint plans. */
 import type { UserNoteLineTarget } from "../../core/liveComments";
-import type { CursorLine } from "../../core/run/commandInputs";
 import type { CopySelectedRowRange } from "../lib/diffSpatial";
 import type { AppTheme } from "../themes";
 import { CODE_ROW_ADD_NOTE_BADGE_TEXT, CODE_ROW_ADD_NOTE_BADGE_WIDTH } from "./codeRowAffordance";
@@ -10,6 +9,7 @@ import {
   type PlannedDiffReviewRow,
 } from "./codeRowLayout";
 import { codeCellView, FULL_CODE_CELL_COL_RANGE, type CodeCellHighlight } from "./CodeCellView";
+import type { CursorHighlight } from "./cursorHighlight";
 import type { DiffRow } from "./diffRows";
 import type { LineHighlightPaintIndex } from "./lineHighlightPaint";
 import {
@@ -29,13 +29,6 @@ export type PlannedCodeReviewRow = Omit<PlannedDiffReviewRow, "row"> & {
   row: CodeDiffRow;
 };
 
-/** Cursor paint inputs consumed by mounted code rows. */
-export interface CodeRowCursorHighlight {
-  stableKey: string;
-  style: Exclude<CursorLine, "off">;
-  side: "old" | "new";
-}
-
 export interface CodeRowViewProps {
   plannedRow: PlannedCodeReviewRow;
   width: number;
@@ -47,7 +40,7 @@ export interface CodeRowViewProps {
   selected: boolean;
   copySelectedRowRange?: CopySelectedRowRange;
   copySelectedSide?: "left" | "right";
-  cursorHighlight?: CodeRowCursorHighlight;
+  cursorHighlight?: CursorHighlight;
   lineHighlights?: LineHighlightPaintIndex;
   showAddNoteBadge?: boolean;
   onHoverRow?: (rowKey: string) => void;

src/ui/diff/renderRows.tsx → src/ui/diff/DiffRowView.tsx

@@ -1,35 +1,15 @@
+/** Adapts and dispatches diff rows to their focused mounted row views. */
 import { memo } from "react";
 import type { UserNoteLineTarget } from "../../core/liveComments";
-import type { CursorLine } from "../../core/run/commandInputs";
 import type { CopySelectedRowRange } from "../lib/diffSpatial";
 import type { AppTheme } from "../themes";
 import { CodeRowView, type PlannedCodeReviewRow } from "./CodeRowView";
 import { legacyPlannedDiffRow, type PlannedDiffReviewRow } from "./codeRowLayout";
+import type { CursorHighlight } from "./cursorHighlight";
 import { DiffMetaRowView, type PlannedDiffMetaReviewRow } from "./DiffMetaRowView";
 import type { DiffRow } from "./diffRows";
 import type { LineHighlightPaintIndex } from "./lineHighlightPaint";
 
-export { isNestedRowMouseAction, markNestedRowMouseAction } from "./rowMouseActions";
-
-export interface CursorHighlight {
-  /** The render plan anchor of the row the cursor rests on, shared with reveal lookups. */
-  stableKey: string;
-  style: Exclude<CursorLine, "off">;
-  /** Which half of a split row the cursor sits on, and where a note would anchor. */
-  side: "old" | "new";
-}
-
-/** Report whether one planned row carries the anchor the cursor rests on. */
-export function plannedRowMatchesCursor(
-  row: { stableKey: string; stableAliasKeys?: readonly string[] },
-  cursor: CursorHighlight | undefined,
-) {
-  return (
-    cursor !== undefined &&
-    (row.stableKey === cursor.stableKey || row.stableAliasKeys?.includes(cursor.stableKey) === true)
-  );
-}
-
 /** Dispatch one planned diff row to its focused metadata or code view. */
 function renderRow(
   plannedRow: PlannedDiffReviewRow,
@@ -95,7 +75,8 @@ function renderRow(
   );
 }
 
-interface DiffRowViewProps {
+/** Inputs accepted by the memoized diff-row facade. */
+export interface DiffRowViewProps {
   /** Complete review-stream row; preferred when the caller owns the shared render plan. */
   plannedRow?: PlannedDiffReviewRow;
   /** Raw row fallback for renderer-only surfaces outside the shared review stream. */

src/ui/diff/DiffSectionBody.tsx

@@ -24,7 +24,8 @@ import { plannedReviewRowVisible } from "./reviewRowGeometry";
 import { buildDiffSectionRowPlan, type DiffSectionRowPlan } from "./diffSectionRowPlan";
 import { resolveVisiblePlannedRowWindow, type VisibleBodyBounds } from "./rowWindowing";
 import { diffMessage, fitText } from "./plannedRowText";
-import { DiffRowView, plannedRowMatchesCursor, type CursorHighlight } from "./renderRows";
+import { DiffRowView } from "./DiffRowView";
+import { plannedRowMatchesCursor, type CursorHighlight } from "./cursorHighlight";
 import { useHighlightedDiff } from "./useHighlightedDiff";
 import { useHighlightedSource } from "./useHighlightedSource";
 

src/ui/diff/cursorHighlight.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, test } from "bun:test";
+import { plannedRowMatchesCursor, type CursorHighlight } from "./cursorHighlight";
+
+const CURSOR: CursorHighlight = {
+  stableKey: "line:new:2",
+  style: "row",
+  side: "new",
+};
+
+describe("plannedRowMatchesCursor", () => {
+  test("matches canonical and alias stable keys", () => {
+    expect(plannedRowMatchesCursor({ stableKey: CURSOR.stableKey }, CURSOR)).toBe(true);
+    expect(
+      plannedRowMatchesCursor(
+        { stableKey: "line:old:2", stableAliasKeys: [CURSOR.stableKey] },
+        CURSOR,
+      ),
+    ).toBe(true);
+  });
+
+  test("rejects absent and unrelated cursors", () => {
+    expect(plannedRowMatchesCursor({ stableKey: "line:new:3" }, CURSOR)).toBe(false);
+    expect(plannedRowMatchesCursor({ stableKey: CURSOR.stableKey }, undefined)).toBe(false);
+  });
+});

src/ui/diff/cursorHighlight.ts

@@ -0,0 +1,22 @@
+/** Defines cursor paint inputs and matches them to stable planned-row identities. */
+import type { CursorLine } from "../../core/run/commandInputs";
+
+/** Cursor paint inputs shared by review planning and mounted code rows. */
+export interface CursorHighlight {
+  /** The render plan anchor of the row the cursor rests on, shared with reveal lookups. */
+  stableKey: string;
+  style: Exclude<CursorLine, "off">;
+  /** Which half of a split row the cursor sits on, and where a note would anchor. */
+  side: "old" | "new";
+}
+
+/** Report whether one planned row carries the anchor the cursor rests on. */
+export function plannedRowMatchesCursor(
+  row: { stableKey: string; stableAliasKeys?: readonly string[] },
+  cursor: CursorHighlight | undefined,
+) {
+  return (
+    cursor !== undefined &&
+    (row.stableKey === cursor.stableKey || row.stableAliasKeys?.includes(cursor.stableKey) === true)
+  );
+}

src/ui/lib/extensionCurrentLine.tsx

@@ -1,6 +1,6 @@
 import type { ExtensionCurrentLinePaint } from "../../extension-api/types";
 import type { DiffRow, SplitLineCell, StackLineCell } from "../diff/diffRows";
-import { DiffRowView } from "../diff/renderRows";
+import { DiffRowView } from "../diff/DiffRowView";
 import type { DiffSectionRowPlan } from "../diff/diffSectionRowPlan";
 import type { LineCursor } from "./lineCursors";
 import type { AppTheme } from "../themes";