fix(sdk): agree removeElement/getElement on duplicate bare ids (#1511)

* fix(sdk): setStyle removes hyphenated properties (was kebab/camel key mismatch)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(sdk): agree removeElement/getElement on duplicate bare ids

A bare hf-id duplicated across a sub-composition element and a top-level
element resolved to different instances: removeElement → resolveScoped →
querySelector (document-order-first, the inner sub-comp dup) while getElement
preferred the canonical match (scopedId === id, the top-level dup). So
removeElement(bareId) removed the inner instance and getElement(bareId) still
found the surviving top-level one — they disagreed.

resolveScoped now resolves an ambiguous BARE id to the canonical (top-level)
instance via isCanonicalScope (walks ancestors for isNewHostBoundary), falling
back to document order when no canonical match exists — matching getElement.
Fully-scoped paths (hf-host/hf-dup) and non-duplicated bare ids are unchanged.

Surfaced by SDK shadow parity (op:delete expected removed, actual present).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/sdk/src/engine/model.ts

@@ -29,25 +29,57 @@ export function parseMutable(html: string): ParsedDocument {
 // ─── Element lookup ───────────────────────────────────────────────────────────
 
 export function findById(document: Document, id: string): Element | null {
-  // CSS.escape is browser-only; hf-ids are restricted identifiers so simple quote-escaping is safe.
+  // Delegate to resolveScoped so patch replay (undo/redo, override-set apply)
-  const escaped = id.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
+  // resolves an id the SAME way forward dispatch does: canonical-first for an
-  return document.querySelector(`[data-hf-id="${escaped}"]`);
+  // ambiguous bare id, and scoped-path ("hf-host/hf-leaf") aware. Otherwise the
+  // two paths disagree on which duplicate a bare id targets and undo reverts the
+  // wrong element. (function declaration is hoisted.)
+  return resolveScoped(document, id);
 }
 
 function escapeHfId(id: string): string {
   return id.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
 }
 
+/**
+ * True when an element lives at the top-level (canonical) scope — i.e. its
+ * scopedId equals its bare id because no ancestor opens a sub-composition
+ * boundary. This mirrors document.ts's scopedId construction (childPrefix only
+ * changes at isNewHostBoundary elements) without rebuilding the snapshot tree.
+ */
+function isCanonicalScope(el: Element): boolean {
+  for (let cur = el.parentElement; cur; cur = cur.parentElement) {
+    if (isNewHostBoundary(cur)) return false;
+  }
+  return true;
+}
+
 /**
  * Resolve a bare or scoped hf-id to its DOM element.
  *
- * Bare id ("hf-x"): equivalent to findById — top-level document search.
+ * Bare id ("hf-x"): top-level document search. When the bare id is ambiguous
+ * (duplicated across a sub-composition and the top level), prefer the canonical
+ * (top-level) instance — the one whose scopedId equals the bare id — falling
+ * back to document order when no canonical match exists. This matches
+ * getElement()'s resolution rule so removeElement / getElement agree on which
+ * instance an ambiguous bare id targets.
+ *
  * Scoped id ("hf-HOST/hf-LEAF", any depth): each segment narrows the search
  * into the subtree of the previous match. This unambiguously addresses an
  * element inside a sub-composition even when bare ids collide.
  */
 export function resolveScoped(document: Document, id: string): Element | null {
   const parts = id.split("/");
+
+  // Bare id: prefer the canonical (top-level) match when one exists, so
+  // resolution agrees with getElement (scopedId === id wins over document order).
+  if (parts.length === 1) {
+    const escaped = escapeHfId(id);
+    const matches = Array.from(document.querySelectorAll(`[data-hf-id="${escaped}"]`));
+    if (matches.length === 0) return null;
+    return matches.find((el) => isCanonicalScope(el)) ?? matches[0] ?? null;
+  }
+
   let context: Element | Document = document;
   for (const part of parts) {
     const escaped = escapeHfId(part);

packages/sdk/src/session.subcomp.test.ts

@@ -13,7 +13,7 @@
 import { describe, it, expect } from "vitest";
 import { parseHTML } from "linkedom";
 import { ensureHfIds } from "@hyperframes/core/hf-ids";
-import { resolveScoped } from "./engine/model.js";
+import { resolveScoped, findById } from "./engine/model.js";
 import { parseMutable } from "./engine/model.js";
 import { buildRoots, flatElements } from "./document.js";
 import { openComposition } from "./session.js";
@@ -49,6 +49,24 @@ describe("resolveScoped — flat id", () => {
     );
     expect(resolveScoped(doc as unknown as Document, "hf-xxxx")).toBeNull();
   });
+
+  // Regression: findById is the patch-replay/undo resolver. It must agree with
+  // resolveScoped (forward dispatch) on an ambiguous bare id — both pick the
+  // canonical (top-level) instance — or undo reverts the wrong duplicate.
+  it("findById resolves an ambiguous bare id to the canonical instance (== resolveScoped)", () => {
+    const doc = makeDoc(
+      inlinedHtml(`
+      <div data-hf-id="hf-host" data-composition-file="sub.html">
+        <p data-hf-id="hf-dup" class="inside">inside</p>
+      </div>
+      <p data-hf-id="hf-dup" class="outside">outside</p>
+    `),
+    ) as unknown as Document;
+    const viaFind = findById(doc, "hf-dup");
+    const viaResolve = resolveScoped(doc, "hf-dup");
+    expect(viaFind).toBe(viaResolve);
+    expect(viaFind?.getAttribute("class")).toBe("outside");
+  });
 });
 
 describe("resolveScoped — scoped id", () => {
@@ -366,6 +384,70 @@ describe("find({ composition })", () => {
   });
 });
 
+// ─── 5b. Ambiguous bare id: removeElement / getElement agreement ──────────────
+
+describe("ambiguous bare id — removeElement and getElement agree", () => {
+  // Inner sub-comp dup appears FIRST in document order; the canonical top-level
+  // dup appears AFTER it. querySelector document-order would return the inner one,
+  // but getElement prefers the canonical (top-level) match. The two APIs must agree.
+  const ambiguousHtml = () =>
+    inlinedHtml(`
+      <div data-hf-id="hf-root" data-hf-root>
+        <div data-hf-id="hf-host" data-composition-file="sub.html">
+          <p data-hf-id="hf-dup" class="inner">inner</p>
+        </div>
+        <p data-hf-id="hf-dup" class="outer">outer</p>
+      </div>
+    `);
+
+  it("bare id resolves to the canonical (top-level) instance, matching getElement", async () => {
+    const comp = await openComposition(ambiguousHtml());
+
+    // getElement prefers the canonical match (scopedId === id) → top-level "outer".
+    const got = comp.getElement("hf-dup");
+    expect(got?.scopedId).toBe("hf-dup");
+    expect(got?.classNames).toContain("outer");
+
+    // removeElement(bareId) must remove the SAME instance getElement returned.
+    comp.removeElement("hf-dup");
+
+    // The canonical top-level instance is gone — getElement(bareId) no longer
+    // finds it (and does NOT silently fall through to the inner sub-comp dup).
+    expect(comp.getElement("hf-dup")).toBeNull();
+
+    // The inner instance survives, addressable only via its fully-scoped path.
+    const inner = comp.getElement("hf-host/hf-dup");
+    expect(inner?.classNames).toContain("inner");
+  });
+
+  it("fully-scoped path still targets the inner instance exactly", async () => {
+    const comp = await openComposition(ambiguousHtml());
+    comp.removeElement("hf-host/hf-dup");
+
+    // Inner gone; canonical top-level survives.
+    const inner = comp.getElement("hf-host/hf-dup");
+    expect(inner).toBeNull();
+    const top = comp.getElement("hf-dup");
+    expect(top?.scopedId).toBe("hf-dup");
+    expect(top?.classNames).toContain("outer");
+  });
+
+  it("non-duplicated bare id still resolves and removes normally", async () => {
+    const html = inlinedHtml(`
+      <div data-hf-id="hf-root" data-hf-root>
+        <div data-hf-id="hf-host" data-composition-file="sub.html">
+          <p data-hf-id="hf-leaf">inside</p>
+        </div>
+        <p data-hf-id="hf-solo">solo</p>
+      </div>
+    `);
+    const comp = await openComposition(html);
+    expect(comp.getElement("hf-solo")?.scopedId).toBe("hf-solo");
+    comp.removeElement("hf-solo");
+    expect(comp.getElement("hf-solo")).toBeNull();
+  });
+});
+
 // ─── 6. Scoped id stability across serialize ──────────────────────────────────
 
 describe("scopedId stability across serialize/re-parse", () => {

packages/studio/src/utils/sdkShadow.test.ts

@@ -312,12 +312,15 @@ describe("runShadowDelete", () => {
     </div>
   </body></html>`;
 
-  it("CORRECTLY reports present/removed for the SDK duplicate-bare-id delete divergence", async () => {
+  it("reports clean delete for a duplicate bare id (SDK resolves removeElement/getElement to the same instance)", async () => {
     const session = await openComposition(DUP_ID_HTML);
     runShadowDelete(session, "hf-dup");
-    // removeElement dropped the inner instance; the top-level one survives, so the
+    // SDK fix (agree removeElement/getElement on duplicate bare ids): both now
-    // readback truthfully flags one mismatch (not silently passed).
+    // resolve a bare id to the canonical (top-level) instance, so removeElement
-    expect(lastShadow()).toMatchObject({ op: "delete", dispatched: true, mismatchCount: 1 });
+    // drops exactly the element the readback checks → no mismatch. (Previously
+    // removeElement dropped the inner instance while the top-level survived,
+    // which this shadow correctly flagged; that divergence is now fixed.)
+    expect(lastShadow()).toMatchObject({ op: "delete", dispatched: true, mismatchCount: 0 });
   });
 });