ng-eventually/packages/polyfill/test/use-shape.test.ts

/**
 * The published `useShape` - what an identity may see of what the SDK handed back.
 *
 * -- Why this file exists, and what it is the answer to --------------------
 * One shared wallet hosts every identity, so the hook's own answer is every identity's
 * objects and the capability filter is the whole of the isolation. Until 2026-09-24 that
 * filter was written for the collection `@ng-org/orm@0.1.2-alpha.18` returned, while the
 * version this package builds against - `alpha.21` - returns a `UseShapeResult` ENVELOPE
 * around it. Three plain members of that envelope (`data`, `promise`, `subscription`) each
 * carried the items and each came back RAW, and no test in this repository could see it,
 * because no fake returned the shape the SDK ships. `test/use-shape-fake.ts` now does, read
 * off the installed package's own `.d.ts`, and this file is what it made possible.
 *
 * Every document below is OBTAINED through the published placement call under the identity
 * that owns it - never named by the test - so "hers" and "his" are facts of the system.
 * Nothing hands a `ReadCap` across the boundary: the stranger holds what a stranger holds.
 */
import { test, expect, afterEach } from "bun:test";
import { configure, storeRegistry, useShape } from "../src/index";
import {
  configureStoreRegistry,
  resetCaps,
  resetConfig,
  resetStoreRegistry,
  setCurrentUser,
} from "../src/shared-wallet/bootstrap";
import { resetRegistryCache } from "../src/shared-wallet/account-registry";
import { makeWallet, SESSION, type Quad } from "./wallet-fake";
import { makeUseShapeHook } from "./use-shape-fake";
import type { FakeShapeHook } from "./use-shape-fake";
import type { NgLike, Nuri, ShapeResult, UseShapeLike } from "../src/model/types";
import type { BaseType, ShapeType } from "@ng-org/shex-orm";
// TYPE-only: no `@ng-org/orm` module is loaded at runtime here. What this line checks is
// the claim the injection type MAKES - that the SDK's OWN React hook is assignable to
// `UseShapeLike` as it stands, with no wrapper and no cast, so `configure({ useShape })`
// is the whole of what a caller writes. It is also what keeps that type honest: it was
// `(...args: any[]) => any`, which no shape could ever contradict.
import type { reactUseShape } from "@ng-org/orm/all";
type _TheSdkHookFits = typeof reactUseShape extends UseShapeLike ? true : never;
const _sdkFits: _TheSdkHookFits = true;
void _sdkFits;

const NoteShape = {
  shape: "urn:use-shape-test:NoteShape",
  schema: {
    "urn:use-shape-test:NoteShape": {
      iri: "urn:use-shape-test:NoteShape",
      predicates: [
        {
          iri: "http://www.w3.org/1999/02/22-rdf-syntax-ns#type",
          readablePredicate: "@type",
          dataTypes: [{ valType: "iri", literals: ["urn:use-shape-test:Note"] }],
          minCardinality: 1,
          maxCardinality: 1,
        },
      ],
    },
  },
} satisfies ShapeType<BaseType>;

/** Everything the local dataset holds - the scope under which this filter is the only
 *  thing between the caller and every identity's objects. */
const EVERYTHING = { graphs: "did:ng:i" };

function inject(hook: FakeShapeHook): void {
  const quads: Quad[] = [];
  const ng: NgLike = makeWallet(quads);
  configure({ ng, useShape: hook.hook });
  configureStoreRegistry({ getSession: async () => SESSION, normalizeId: (id) => id.trim() });
  resetRegistryCache();
  resetCaps();
  setCurrentUser(null);
}

/** A document that really belongs to `who` - created by them, through the published call,
 *  which is also what files its cap in their keyring. */
async function documentOf(who: string): Promise<Nuri> {
  setCurrentUser(who);
  return storeRegistry.createEntityDoc(await storeRegistry.protectedStore());
}

/** One ORM object placed in `doc`, as the ORM itself carries it. */
function noteIn(doc: Nuri, id: string): BaseType {
  return { "@id": `${doc}:q:${id}`, "@graph": doc } as BaseType;
}

afterEach(() => {
  resetConfig();
  resetStoreRegistry();
  resetCaps();
  setCurrentUser(null);
});

// -- THE RIGHTS CASE: the stranger ------------------------------------------

// The defect, stated as a test. Each of the three members below is one the `alpha.21`
// declaration gives the items to, and each used to hand back the unfiltered collection.
test("useShape: no member of the result reaches a document this identity holds no cap for", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"), noteIn(his, "b1"));

  setCurrentUser("bob");
  const result: ShapeResult = useShape(NoteShape, EVERYTHING);

  // `data` - what the SDK's own example destructures first.
  expect([...(result.data as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([his]);
  expect((result.data as { size: number }).size).toBe(1);
  // `promise` - the same collection, one await away.
  expect([...((await result.promise) as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([his]);
  // `subscription` - the SDK's own handle, which reads and writes with no filter at all.
  expect(() => result.subscription).toThrow(/RdfOrmSubscription/);

  // and the collection underneath really does hold both, so it is the filter that
  // removed one rather than the fake never having offered it.
  expect([...(hook.raw() as Iterable<BaseType>)]).toHaveLength(2);
});

// Iterating is not the only way in, and the members a reactive set puts forward are the
// ones a consumer reaches for first. Same rule as the collection view's own regression.
test("useShape: the item-yielding members of `data` are filtered too, not just iteration", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  const foreign = noteIn(hers, "a1");
  hook.items.push(foreign, noteIn(his, "b1"));

  setCurrentUser("bob");
  const data = useShape(NoteShape, EVERYTHING).data as {
    values(): Iterable<BaseType>;
    forEach(cb: (v: BaseType) => void): void;
    has(v: BaseType): boolean;
  };
  expect([...data.values()].map((o) => o["@graph"])).toEqual([his]);
  const seen: string[] = [];
  data.forEach((o) => seen.push(o["@graph"]));
  expect(seen).toEqual([his]);
  expect(data.has(foreign)).toBe(false);
});

// -- THE OTHER DIRECTION: the holder is served ------------------------------

// A repair that closes a leak by making the call unusable has traded one defect for
// another. Every member the declaration offers a holder is exercised here on their OWN
// data, and the two page commands with it.
test("useShape: the holder reads their own items through every member the SDK offers", async () => {
  const hook = makeUseShapeHook({ paginated: true });
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"), noteIn(his, "b1"), noteIn(hers, "a2"));

  setCurrentUser("alice");
  const result: ShapeResult = useShape(NoteShape, EVERYTHING);

  expect([...(result.data as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([hers, hers]);
  expect((result.data as { size: number }).size).toBe(2);
  expect([...((await result.promise) as Iterable<BaseType>)]).toHaveLength(2);
  // The load state is a boolean and passes on its own, with no entry naming it. It reads
  // `true` on a payload that HAS arrived, because the shipped hook computes it as
  // `ormSubscription.isReady` while the declaration beside it says the opposite. That
  // inversion is upstream's; the fake reproduces it rather than correcting it, and this
  // assertion is what stops anyone here quietly making the target nicer than it is.
  expect(result.isLoading).toBe(true);
  // The page commands forward: they return `void`, and what they load lands in a
  // collection only ever read back through the filter.
  result.nextPage?.();
  result.previousPage?.();
  expect(hook.pages).toEqual(["next", "previous"]);
  // Reading `data` twice hands back the same view, so a caller may put it in a
  // dependency array without it looking like new data on every read.
  expect(result.data).toBe(result.data);
});

// Before the first cap exists the emulation is not in force, exactly as `getObjects` and
// `useShapeQuery` behave: a consumer that never touches caps keeps reading everything,
// and gets the SDK's own object back untouched.
test("useShape: passthrough while no cap has been issued", () => {
  const hook = makeUseShapeHook();
  inject(hook);
  hook.items.push(noteIn("did:ng:o:someone" as Nuri, "x"));
  const result: ShapeResult = useShape(NoteShape, EVERYTHING);
  expect([...(result.data as Iterable<BaseType>)]).toHaveLength(1);
  expect(result.subscription).not.toBeUndefined();
});

// Upstream: "If the conf is explicitly set to `undefined`, the returned data is
// `undefined` and `isLoading` is false". Nothing was opened, so there is nothing to
// refuse, and `subscription` answers the SDK's own value rather than throwing.
test("useShape: an undefined config answers undefined rather than refusing", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  await documentOf("alice");
  setCurrentUser("alice");
  const result: ShapeResult = useShape(NoteShape, undefined);
  expect(result.data).toBeUndefined();
  expect(result.promise).toBeUndefined();
  expect(result.subscription).toBeUndefined();
  expect(result.isLoading).toBe(false);
});

// -- A MUTATION MAY NOT REACH PAST WHAT THE VIEW SHOWS ---------------------

// THE RIGHTS CASE, second kind, and it is the member the SDK's own example reaches for
// first (`expenses.add({...})`). `Set.prototype.add` RETURNS THE COLLECTION so calls can
// be chained - measured, not assumed - so a mutation forwarded bound to the target handed
// the unfiltered collection back as its return value. The view filtered every way IN and
// gave the whole set away on the way OUT.
test("useShape: adding an item does not hand back the unfiltered collection", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"), noteIn(his, "b1"));

  setCurrentUser("bob");
  const data = useShape(NoteShape, EVERYTHING).data as {
    add(item: BaseType): unknown;
    [Symbol.iterator](): Iterator<BaseType>;
  };
  expect([...data].map((o) => o["@graph"])).toEqual([his]); // the way in is filtered

  const handedBack = data.add(noteIn(his, "b2"));
  expect(handedBack).not.toBe(hook.raw());
  // Chaining still works, and what it chains onto is the VIEW: still bob's documents only.
  expect([...(handedBack as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([his, his]);
  // and the write really did reach the collection underneath.
  expect([...(hook.raw() as Iterable<BaseType>)]).toHaveLength(3);
});

// `has(item)` has always refused to answer about an item the holder may not read. Acting
// on one is the same question with a worse consequence, and the two disagreed: `has` said
// no while `delete` removed it.
test("useShape: deleting reaches only what the view shows", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  const hersItem = noteIn(hers, "a1");
  hook.items.push(hersItem, noteIn(his, "b1"));

  setCurrentUser("bob");
  const data = useShape(NoteShape, EVERYTHING).data as {
    delete(item: BaseType): boolean;
    has(item: BaseType): boolean;
    clear(): void;
  };
  expect(data.has(hersItem)).toBe(false);
  expect(data.delete(hersItem)).toBe(false);
  expect([...(hook.raw() as Iterable<BaseType>)]).toHaveLength(2); // hers survives

  // and emptying the view empties the view, not the collection every identity shares.
  data.clear();
  expect([...(hook.raw() as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([hers]);
});

// The page commands forward, and their RESULT is held to the same rule as every other
// member. `nextPage` is declared `() => void` and yields nothing today, so this pins the
// RULE rather than a live defect - which is the point: "it returns void" was the written,
// never-executed ground on which `add` was forwarded, and `add` returns the collection.
test("useShape: a page command that handed something back would be refused, not forwarded", async () => {
  const base = makeUseShapeHook({ paginated: true });
  const leaky: FakeShapeHook = {
    ...base,
    hook: ((shapeType, conf) => ({
      ...base.hook(shapeType, conf),
      nextPage: (): void => base.raw() as undefined,
    })) as UseShapeLike,
  };
  inject(leaky);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  base.items.push(noteIn(hers, "a1"), noteIn(his, "b1"));

  setCurrentUser("bob");
  const result: ShapeResult = useShape(NoteShape, EVERYTHING);
  expect(() => result.nextPage?.()).toThrow(/not filtered/i);
});

// THE THIRD MUTATION, and the one that was ungated. `delete` and `clear` asked `keep` and
// `add` did not, which made the published rule true by coincidence: the ungated `add`
// MANUFACTURED the state the other two then handled partially. Bob plants an object into
// ALICE's document, never sees it again - the view filters it straight back out - and the
// ORM's two-way binding commits it there. Then `clear()` leaves it behind.
//
// Each of the three is run here against a document this identity does not hold, and the
// collection underneath is checked afterwards. That is the contract's mutation sentence,
// clause by clause, executed rather than read.
test("useShape: none of the three mutations reaches a document this identity holds no cap for", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  const hersItem = noteIn(hers, "a1");
  hook.items.push(hersItem, noteIn(his, "b1"));

  setCurrentUser("bob");
  const data = useShape(NoteShape, EVERYTHING).data as {
    add(item: BaseType): unknown;
    delete(item: BaseType): boolean;
    clear(): void;
    has(item: BaseType): boolean;
  };

  // add - refuses, because it has no return value meaning "it did not happen".
  expect(() => data.add(noteIn(hers, "PLANT"))).toThrow(/does not hold the cap/i);
  // delete - answers `false`, which is the Set contract's own word for "not there" and is
  // true of the view.
  expect(data.has(hersItem)).toBe(false);
  expect(data.delete(hersItem)).toBe(false);
  // clear - empties the view, which holds none of hers.
  data.clear();

  // The collection underneath is exactly as it was, minus bob's own item.
  expect([...(hook.raw() as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([hers]);
  // And the holder's OWN write still goes through and still reaches the collection.
  expect([...(data.add(noteIn(his, "b2")) as Iterable<BaseType>)].map((o) => o["@graph"]))
    .toEqual([his]);
  expect([...(hook.raw() as Iterable<BaseType>)]).toHaveLength(2);
});

// A write to the collection itself is refused. Upstream's ordered `readOnlyArray` refuses
// these too, so here the two agree - which is the point of the fake now building the REAL
// collection kinds. That the VIEW refuses on its own account, whatever the target allows,
// is proved one floor down in `read-filter.test.ts` against a plain array, because relying
// on the target's guarantee is relying on something this view does not promise and does
// not control. `length = 0` in particular defeated the gated `clear` outright.
test("useShape: a write to the view itself is refused, whatever the collection underneath allows", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"), noteIn(hers, "a2"));

  setCurrentUser("bob");
  const data = useShape(NoteShape, { ...EVERYTHING, orderBy: { liveMark: "asc" } }).data as
    Record<number, unknown> & { length: number };
  expect(() => {
    data[0] = { "@id": "SPY", "@graph": "did:ng:o:spy" };
  }).toThrow(/not filtered/i);
  expect(() => {
    delete data[0];
  }).toThrow(/not filtered/i);
  expect(() => {
    data.length = 0;
  }).toThrow(/not filtered/i);
  // The collection underneath is untouched.
  expect([...(hook.raw() as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([hers, hers]);
});

// The descriptor trap handed an ACCESSOR back untouched, so the getter behind it - which
// reads the TARGET - was a door around the view. Not reachable on the shape that ships,
// where every member reports a data descriptor; reachable on the next one, which is what
// this view claims to be safe for.
test("useShape: an accessor member is read through the view, not around it", async () => {
  const base = makeUseShapeHook();
  const withGetter: FakeShapeHook = {
    ...base,
    hook: ((shapeType, conf) => {
      const built = base.hook(shapeType, conf);
      const raw = base.raw();
      return {
        isLoading: built.isLoading,
        promise: built.promise,
        subscription: built.subscription,
        get data(): unknown {
          return raw;
        },
      };
    }) as UseShapeLike,
  };
  inject(withGetter);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  base.items.push(noteIn(hers, "a1"), noteIn(his, "b1"));

  setCurrentUser("bob");
  const result: ShapeResult = useShape(NoteShape, EVERYTHING);
  const described = Object.getOwnPropertyDescriptor(result, "data");
  expect(typeof described?.get).toBe("function");
  const throughTheDescriptor = described?.get?.();
  expect(throughTheDescriptor).not.toBe(base.raw());
  expect([...(throughTheDescriptor as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([his]);
});

// -- SAFE FOR A SHAPE NOBODY HAS SEEN --------------------------------------

/** What a later `@ng-org/orm` might hand back: the six members of `alpha.21` plus three
 *  nobody has declared - one holding the collection, one COUNTING it, one yielding an item. */
interface LaterResult extends ShapeResult {
  readonly rows: unknown;
  readonly totalCount: number;
  readonly sample: () => unknown;
}

// WHAT A MEMBER NOBODY HAS DECIDED ANSWERS, and the third version of this test, because the
// first two were wrong in the same way. It asserted that `totalCount` PASSING was correct,
// on the ground that "a primitive cannot hold a reference to anything" - six lines above a
// test whose own comment calls an unfiltered count the defect. The suite asserted both that
// the leak was correct and that it was the defect, which is worse than the leak: it would
// have kept it green for ever.
//
// A count IS a primitive and DOES describe the items, and no type-level test separates it
// from a page size. So nothing undecided passes now, whatever its type.
test("useShape: no member this package has not decided is answered, whatever its type", async () => {
  const base = makeUseShapeHook();
  const later: FakeShapeHook = {
    ...base,
    hook: ((shapeType, conf) => {
      const result: LaterResult = {
        ...base.hook(shapeType, conf),
        rows: base.raw(),
        totalCount: 7,
        sample: () => [...(base.raw() as Iterable<BaseType>)][0],
      };
      return result;
    }) as UseShapeLike,
  };
  inject(later);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  base.items.push(noteIn(hers, "a1"), noteIn(his, "b1"));

  setCurrentUser("bob");
  const result = useShape(NoteShape, EVERYTHING) as LaterResult;

  // An OBJECT member holds the collection, so it is refused at the read - there is no
  // later moment to refuse it at.
  expect(() => result.rows).toThrow(/not filtered/i);
  // A FUNCTION member is refused at the CALL, so reading it (a logger, a `typeof` guard)
  // is not itself refused.
  expect(typeof result.sample).toBe("function");
  expect(() => result.sample()).toThrow(/not filtered/i);
  // A PRIMITIVE is refused too, and this is the case the earlier version of this test had
  // backwards: `totalCount` counts items the holder may not read. Three exist, one may be
  // read, and the number that may not be published is 3.
  expect([...(result.data as Iterable<BaseType>)]).toHaveLength(1);
  expect(() => result.totalCount).toThrow(/not filtered/i);
  // A member the SDK does not carry at all answers `undefined`: there is nothing behind it
  // to derive anything from, so refusing would refuse a question nobody asked.
  expect((result as unknown as { neverShipped?: unknown }).neverShipped).toBeUndefined();
});

// An `orderBy` config makes the collection an ARRAY (upstream `SubscriptionData`), whose
// count is spelled `length` and is a number - so it used to pass as a harmless primitive
// while publishing how many items the holder may NOT read.
test("useShape: an ordered result does not publish the unfiltered count", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"), noteIn(his, "b1"), noteIn(his, "b2"));

  setCurrentUser("alice");
  const data = useShape(NoteShape, { ...EVERYTHING, orderBy: { liveMark: "asc" } }).data;
  expect(Array.isArray(hook.raw())).toBe(true);
  expect((hook.raw() as BaseType[]).length).toBe(3);
  expect((data as { length: number }).length).toBe(1);
  expect([...(data as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([hers]);
  // An index names a position in the READABLE items, so the holder reads their own by
  // index and the positions past them do not exist at all. `Object.keys` and `in` have to
  // agree with `length`, or the count comes back out through the other three.
  expect((data as Record<number, BaseType>)[0]!["@graph"]).toBe(hers);
  expect((data as Record<number, BaseType>)[1]).toBeUndefined();
  expect(Object.keys(data as object)).toEqual(["0"]);
  expect(1 in (data as object)).toBe(false);
  expect(JSON.parse(JSON.stringify(data)) as BaseType[]).toHaveLength(1);
});

// REGRESSION, found by re-running the adversary on the first fix (2026-09-24).
// `Object.getOwnPropertyDescriptor` reads a property WITHOUT the `get` trap, so a view
// that filtered `get` alone handed the raw value straight back to whoever asked for the
// descriptor - including `subscription`, the one member `get` refuses outright. Everything
// built on it goes the same way: a spread, `Object.entries`, a console inspection.
test("useShape: the descriptor of a member answers exactly what reading it answers", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"), noteIn(his, "b1"));

  setCurrentUser("bob");
  const result: ShapeResult = useShape(NoteShape, EVERYTHING);

  const described = Object.getOwnPropertyDescriptor(result, "data");
  expect(described?.value).toBe(result.data);
  expect(described?.value).not.toBe(hook.raw());
  expect([...(described?.value as Iterable<BaseType>)].map((o) => o["@graph"])).toEqual([his]);
  expect(() => Object.getOwnPropertyDescriptor(result, "subscription")).toThrow(
    /RdfOrmSubscription/,
  );
});

// REGRESSION (fourth adversarial pass). The envelope view had TWO traps where the
// collection view had nine, so the SDK's own result object could be written to through it -
// the same fix applied in one of two places, which is the shape of every defect this file
// has had. Both views now take the write traps from ONE object, so one cannot be repaired
// without the other.
test("useShape: the result object cannot be written to through the view either", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"));

  setCurrentUser("bob");
  const result: ShapeResult = useShape(NoteShape, EVERYTHING);
  const asRecord = result as unknown as Record<string, unknown>;
  expect(() => {
    delete asRecord["data"];
  }).toThrow(/not filtered/i);
  expect(() => {
    asRecord["isLoading"] = true;
  }).toThrow(/not filtered/i);
  expect(() => Object.setPrototypeOf(result, { stolen: 1 })).toThrow(/not filtered/i);
  expect(() => Object.preventExtensions(result)).toThrow(/not filtered/i);
  // The request state still reads, because it is DECIDED rather than passed: it describes
  // the request, not the items.
  expect(typeof result.isLoading).toBe("boolean");
});

// REGRESSION (fourth adversarial pass). The write gate asked `keep`, which answers `true`
// for an object naming NO document - right for a read, where there is no cap to ask about,
// and VACUOUS for a write: the object landed in the collection every identity shares. The
// only thing stopping it was upstream raising "@graph is missing", which is a guarantee
// borrowed from the target - the very thing removed for `set`/`deleteProperty` one round
// earlier and left standing here.
test("useShape: adding an object that names no document at all is refused", async () => {
  const hook = makeUseShapeHook();
  inject(hook);
  const hers = await documentOf("alice");
  const his = await documentOf("bob");
  hook.items.push(noteIn(hers, "a1"));

  setCurrentUser("bob");
  const data = useShape(NoteShape, EVERYTHING).data as { add(item: BaseType): unknown };
  expect(() => data.add({ "@id": "PLANT" } as BaseType)).toThrow(/names no document/i);
  expect([...(hook.raw() as Iterable<BaseType>)]).toHaveLength(1);
  // A write that names a document this identity holds still goes through.
  data.add(noteIn(his, "b1"));
  expect([...(hook.raw() as Iterable<BaseType>)]).toHaveLength(2);
});