Files
ng-eventually/packages/client/test/cross-user-access.test.ts
T
Sylvain Duchesne ae9c32e271 Align the cap emulation on NextGraph's model, and confine it to a virtual user
Two batches, verified against nextgraph-rs throughout.

P1a — the capability surface. Reading was an ACL (Map<doc, Set<principal>>),
the exact inversion of key possession. It is now possession: `capFor(nuri)` is
the only question, there is no principal parameter anywhere, and nothing turns
a bare reference into a cap. Sharing is `shareCap(cap, toInbox)`, a Link
deposit; receiving needs no operation. `Nuri` and `ReadCap` are template
literal types, so passing a bare reference where a cap belongs is a compile
error, with runtime guards behind it for JavaScript callers.

The virtual user boundary. Every access function is now confined to the
connected user, through two rules on one criterion (possession), implemented in
two places so a lapse in either is caught by the other: authorization at the
passage points, and "do not even attempt" at the callers. The polyfill's own
machinery moved to physical.ts — unguarded, never exported — which replaced an
exemption list: the machinery no longer gets waved through the guard, it calls
something the guard never saw.

Removed, as emulating capabilities the target does not have:
- discovery.ts and its global index. There is no discovery in NextGraph; you
  follow links. It also pooled user data across wallets.
- the cross-account fan-out (listEntityDocs, resolveReadGraphs, allAccounts,
  loadShim), which was cross-user enumeration by construction.
- resolveInboxAnchor, a single inbox common to every user.

Caps are now stored where NextGraph stores them, and read back rather than
recomputed: AddRepo on the store's Store branch for documents a user creates,
AddLink on its User branch for caps received. Inboxes belong to someone — the
user's own, plus one per document — and connecting a user drains them all;
that is the library's job, not the app's.

Corrections worth recording: a ReadCap is `r:`, not `:k:` (reported by
NextGraph's developer, verified in BlockRef::readcap_nuri); received caps DO
have a register (AddLink), contrary to what this repo's notes claimed; and
"wallet" upstream means keyring — what owns three stores is a user, so the
vocabulary follows.

The cap value is the constant OK: the only question the emulation answers is
whether a cap is held. P1b replaces that one constant with a real key.

After this the shape is right and the isolation is still fake. Nothing here may
be described as anonymous or private.
2026-08-03 11:22:01 +02:00

425 lines
17 KiB
TypeScript

/**
* Cross-user access — the scenario that proves the model end to end.
*
* Alice owns a PROTECTED document and a PUBLIC one, and the public one carries a
* REFERENCE to the protected one. Then:
*
* - **Bob** has the public document's link. He reads it, sees the reference, and
* cannot read what it points at. Naming is not reading, and publication is
* **not recursive**: a public object may point at private content without
* disclosing it.
* - **Charlie** has the public document's link AND was given the protected
* document's cap. Same reference, same path — he reads through it.
* - **Bob, dynamically**: Alice delivers the cap to Bob's inbox. Processing the
* inbox files it, which fires the held-caps signal, which re-runs the read — the
* protected document appears with nothing else happening.
*
* The difference between Bob and Charlie is ONLY what what they hold holds. There is
* no authorization list anywhere, and nobody was named to the registry.
*/
import { test, expect, mock, afterAll } from "bun:test";
import { createEntityDoc, documentInbox, resetRegistryCache, walletInbox } from "../src/store-registry";
import type { RegistrySession } from "../src/store-registry";
import {
configure,
configureStoreRegistry,
resetStoreRegistry,
resetConfig,
capFor,
getCaps,
resetCaps,
setCurrentUser,
shareCap,
connectedUser,
} from "../src/polyfill";
import { post, read as readInbox } from "../src/inbox";
import { readUnion } from "../src/read-model";
import { sparqlUpdate } from "../src/docs";
import type { Nuri } from "../src/types";
afterAll(() => {
resetConfig();
resetStoreRegistry();
resetCaps();
setCurrentUser(null);
});
const SESSION: RegistrySession = { sessionId: "sid-x", privateStoreId: "PRIV-X" };
const SHIM = "urn:ng-eventually:shim";
const INBOX = "urn:ng-eventually:inbox";
/** The predicate Alice uses to point from her public doc at her protected one. */
const REFERS_TO = "urn:e2e:refersTo";
const SECRET = "urn:e2e:secret";
interface Quad { g: string; s: string; p: string; o: string }
function unescapeLiteral(s: string): string {
let out = "";
for (let i = 0; i < s.length; i++) {
if (s[i] === "\\" && i + 1 < s.length) {
const next = s[++i];
out += next === "n" ? "\n" : next === "r" ? "\r" : next === "t" ? "\t" : next!;
} else out += s[i];
}
return out;
}
/** A stateful fake `ng`: the shim SPARQL, the inbox SPARQL, and the anchored
* per-doc `?s ?p ?o` read the read-model uses. */
function makeFakeNg() {
const quads: Quad[] = [];
let docCounter = 0;
const doc_create = mock(async () => `did:ng:o:doc${++docCounter}`);
const sparql_update = mock(async (...a: unknown[]) => {
const query = a[1] as string;
const anchor = a[2] as string | undefined;
if (!anchor) return undefined;
const body = query.replace(/^\s*INSERT DATA\s*\{/, "").replace(/\}\s*$/, "");
const sm = body.match(/<([^>]+)>/);
if (!sm) return undefined;
const s = sm[1]!;
const pairRe = /(?:a|<([^>]+)>)\s+(?:"((?:[^"\\]|\\.)*)"|<([^>]+)>)/g;
let m: RegExpExecArray | null;
const after = body.slice(body.indexOf(sm[0]) + sm[0].length);
while ((m = pairRe.exec(after)) !== null) {
const p = m[1] ?? (query.includes(`${INBOX}:Deposit`) ? `${INBOX}:Deposit` : `${SHIM}:Account`);
const o = m[2] !== undefined ? unescapeLiteral(m[2]) : (m[3] ?? "");
quads.push({ g: anchor, s, p, o });
}
return undefined;
});
const sparql_query = mock(async (...a: unknown[]) => {
const query = a[1] as string;
const anchor = a[3] as string | undefined;
if (query.includes(`<${SHIM}:shimDoc>`)) {
return { results: { bindings: quads.filter((q) => q.g === anchor && q.p === `${SHIM}:shimDoc`).map((q) => ({ shimDoc: { value: q.o } })) } };
}
if (query.includes(`<${SHIM}:id>`)) {
const subjM = query.match(/<([^>]+)>\s+a\s+<urn:ng-eventually:shim:Account>/);
const only = subjM ? subjM[1]! : null;
const bySubject = new Map<string, Record<string, string>>();
for (const q of quads) {
if (q.g !== anchor) continue;
if (only !== null && q.s !== only) continue;
const rec = bySubject.get(q.s) ?? {};
if (q.p === `${SHIM}:id`) rec.id = q.o;
if (q.p === `${SHIM}:docPublic`) rec.docPublic = q.o;
if (q.p === `${SHIM}:docProtected`) rec.docProtected = q.o;
if (q.p === `${SHIM}:docPrivate`) rec.docPrivate = q.o;
bySubject.set(q.s, rec);
}
return {
results: {
bindings: [...bySubject.values()].filter((r) => r.id).map((r) => ({
id: { value: r.id! },
docPublic: { value: r.docPublic ?? "" },
docProtected: { value: r.docProtected ?? "" },
docPrivate: { value: r.docPrivate ?? "" },
})),
},
};
}
if (query.includes(`<${INBOX}:payload>`)) {
const bySubject = new Map<string, Record<string, string>>();
for (const q of quads) {
if (q.g !== anchor) continue;
const rec = bySubject.get(q.s) ?? {};
if (q.p === `${INBOX}:payload`) rec.payload = q.o;
if (q.p === `${INBOX}:ts`) rec.ts = q.o;
if (q.p === `${INBOX}:from`) rec.from = q.o;
bySubject.set(q.s, rec);
}
return {
results: {
bindings: [...bySubject.values()]
.filter((r) => r.payload !== undefined && r.ts !== undefined)
.map((r) => {
const row: Record<string, { value: string }> = { payload: { value: r.payload! }, ts: { value: r.ts! } };
if (r.from !== undefined) row.from = { value: r.from };
return row;
}),
},
};
}
// User-branch `link` SELECT (the emulated AddLink records).
// User-branch `inboxCap` SELECT (the emulated AddInboxCap records).
if (query.includes(`<${SHIM}:inboxCap>`)) {
return { results: { bindings: quads.filter((q) => q.g === anchor && q.p === `${SHIM}:inboxCap`).map((q) => ({ c: { value: q.o } })) } };
}
// Store-branch `readCap` SELECT (the emulated AddRepo records).
if (query.includes(`<${SHIM}:readCap>`)) {
return { results: { bindings: quads.filter((q) => q.g === anchor && q.p === `${SHIM}:readCap`).map((q) => ({ c: { value: q.o } })) } };
}
if (query.includes(`<${SHIM}:link>`)) {
return { results: { bindings: quads.filter((q) => q.g === anchor && q.p === `${SHIM}:link`).map((q) => ({ c: { value: q.o } })) } };
}
if (query.includes(`<${SHIM}:contains>`)) {
return { results: { bindings: quads.filter((q) => q.g === anchor && q.p === `${SHIM}:contains`).map((q) => ({ e: { value: q.o } })) } };
}
// Anchored per-doc read (readUnion `SELECT ?s ?p ?o`) — the document's content.
return {
results: {
bindings: quads
.filter((q) => q.g === anchor)
.map((q) => ({ s: { value: q.s }, p: { value: q.p }, o: { value: q.o } })),
},
};
});
return { doc_create, sparql_update, sparql_query, _quads: quads };
}
function inject() {
const ng = makeFakeNg();
configure({ ng: ng as any, useShape: (() => {}) as any });
configureStoreRegistry({ getSession: async () => SESSION, normalizeId: (id) => id.trim().toLowerCase() });
resetRegistryCache();
resetCaps();
setCurrentUser(null);
return ng;
}
/** Write one triple into `doc`, as the consumer's write path would. */
async function write(doc: Nuri, p: string, o: string): Promise<void> {
await sparqlUpdate(SESSION.sessionId, `INSERT DATA { <${doc}> <${p}> "${o}" }`, doc, "test");
}
/** The values `p` carries in the documents `docs`, as the current holder reads them. */
async function readValues(docs: Nuri[], p: string): Promise<string[]> {
const subjects = await readUnion(docs);
return subjects.flatMap((s) => s.props[p] ?? []);
}
/**
* Alice's world: a protected document holding a secret, and a public document that
* REFERS to it by bare NURI. Returns what each actor could plausibly come to hold.
*/
async function aliceSetsUpHerDocuments() {
setCurrentUser("alice");
const protDoc = await createEntityDoc("alice", "protected");
await write(protDoc, SECRET, "the-protected-content");
const pubDoc = await createEntityDoc("alice", "public");
// The reference is the BARE NURI of the protected document: it names it, and
// grants nothing. This is the whole point of the scenario.
await write(pubDoc, REFERS_TO, protDoc);
const pubLink = capFor(pubDoc)!; // the shareable repo link of the public doc
const protCap = capFor(protDoc)!; // the cap Alice may hand to whoever she chooses
return { protDoc, pubDoc, pubLink, protCap };
}
/** Follow the reference found in the public document — what a reader actually does. */
function referenceFoundIn(values: string[]): Nuri {
const ref = values[0];
expect(ref).toBeDefined();
return ref as Nuri;
}
test("Bob: reads the public document, sees the reference, and cannot read through it", async () => {
inject();
const { protDoc, pubDoc, pubLink } = await aliceSetsUpHerDocuments();
setCurrentUser("bob");
// Bob was given the public document's link — "whoever has the URL reads it".
getCaps().learn(pubLink);
// He reads the public document and finds the reference.
const refs = await readValues([pubDoc], REFERS_TO);
const ref = referenceFoundIn(refs);
expect(ref).toBe(protDoc); // he can NAME Alice's protected document
// …and that is all it gets him: no cap, no read. Publication is NOT recursive.
expect(capFor(ref)).toBeUndefined();
expect(await readValues([ref], SECRET)).toEqual([]);
});
test("Charlie: same public document, same reference — and he reads through it", async () => {
inject();
const { protDoc, pubDoc, pubLink, protCap } = await aliceSetsUpHerDocuments();
const CHARLIE_INBOX = await walletInbox("charlie");
// Alice decides Charlie may read that ONE document, and delivers its cap to his
// inbox. She names no principal to the registry; she addresses an inbox.
setCurrentUser("alice");
await shareCap(protCap, CHARLIE_INBOX);
setCurrentUser("charlie");
getCaps().learn(pubLink);
await readInbox(CHARLIE_INBOX); // processing the inbox files the cap
const ref = referenceFoundIn(await readValues([pubDoc], REFERS_TO));
expect(ref).toBe(protDoc);
expect(capFor(ref)).toBe(protCap);
expect(await readValues([ref], SECRET)).toEqual(["the-protected-content"]);
});
test("the ONLY difference between Bob and Charlie is what what they hold holds", async () => {
inject();
const { protDoc, pubLink, protCap } = await aliceSetsUpHerDocuments();
const CHARLIE_INBOX = await walletInbox("charlie");
setCurrentUser("alice");
await shareCap(protCap, CHARLIE_INBOX);
setCurrentUser("bob");
getCaps().learn(pubLink);
const bobSees = await readValues([protDoc], SECRET);
setCurrentUser("charlie");
getCaps().learn(pubLink);
await readInbox(CHARLIE_INBOX);
const charlieSees = await readValues([protDoc], SECRET);
expect(bobSees).toEqual([]);
expect(charlieSees).toEqual(["the-protected-content"]);
});
// The dynamic version: Bob is refused, then the cap lands in his inbox and the read
// that was empty becomes full — with nothing re-declared and nobody re-authorized.
test("dynamic: a cap delivered to Bob's inbox makes the refused document readable, and signals it", async () => {
inject();
const { pubDoc, pubLink, protCap } = await aliceSetsUpHerDocuments();
const BOB_INBOX = await walletInbox("bob");
setCurrentUser("bob");
getCaps().learn(pubLink);
const ref = referenceFoundIn(await readValues([pubDoc], REFERS_TO));
// Before: named, unreadable.
expect(await readValues([ref], SECRET)).toEqual([]);
// A reader that re-reads whenever what it holds changes — this is exactly what
// `watchShape` wires internally, played here on an ad-hoc read.
let reread = 0;
let latest: string[] = [];
const unsub = getCaps().onChange(() => {
reread += 1;
void readValues([ref], SECRET).then((v) => (latest = v));
});
// Alice delivers the cap. Bob's client processes his inbox — the only thing that
// happens; no "receive" call exists.
setCurrentUser("alice");
await shareCap(protCap, BOB_INBOX);
setCurrentUser("bob");
await readInbox(BOB_INBOX);
// Filing the cap fired the signal…
expect(reread).toBeGreaterThan(0);
await Promise.resolve();
await new Promise((r) => setTimeout(r, 0));
// …and the read that was empty now yields the content.
expect(capFor(ref)).toBe(protCap);
expect(latest).toEqual(["the-protected-content"]);
expect(await readValues([ref], SECRET)).toEqual(["the-protected-content"]);
unsub();
});
test("a bare reference to the PUBLIC document is not enough either — the link is", async () => {
inject();
const { pubDoc, pubLink } = await aliceSetsUpHerDocuments();
setCurrentUser("bob");
// Bob knows the public document's NURI but was never given its link.
expect(await readValues([pubDoc], REFERS_TO)).toEqual([]);
getCaps().learn(pubLink);
expect((await readValues([pubDoc], REFERS_TO)).length).toBe(1);
});
// THE POINT OF THE LINK: a cap survives because it was APPLIED, not because the
// inbox is re-read. Upstream, processing an inbox message files it — `AddLink
// { read_cap }` on the User branch of the private store — and the queue is consumed.
// Re-reading a queue to recover state is using it as a database.
test("a Link is APPLIED durably: the cap survives with the inbox emptied", async () => {
const ng = inject();
const { protDoc, protCap } = await aliceSetsUpHerDocuments();
const bobInbox = await walletInbox("bob");
setCurrentUser("alice");
await shareCap(protCap, bobInbox);
// Bob connects: the library restores + drains, with nothing asked of the app.
setCurrentUser("bob");
await connectedUser();
expect(await readValues([protDoc], SECRET)).toEqual(["the-protected-content"]);
// Now EMPTY the inbox — as a consumed queue would be — and drop every in-memory
// cap, then re-arm the emulation so the boundary is actually in force again.
for (let k = ng._quads.length - 1; k >= 0; k--) {
if (ng._quads[k]!.g === bobInbox) ng._quads.splice(k, 1);
}
resetCaps();
setCurrentUser("alice");
await createEntityDoc("alice", "private"); // re-arms: a cap exists again
setCurrentUser("bob");
expect(await readValues([protDoc], SECRET)).toEqual([]); // bob holds nothing yet
// Connecting restores it — from the User branch, since the inbox has nothing left.
await connectedUser();
expect(capFor(protDoc)).toBe(protCap);
expect(await readValues([protDoc], SECRET)).toEqual(["the-protected-content"]);
});
test("connecting a user that does not exist provisions nothing", async () => {
inject();
setCurrentUser("nobody");
await connectedUser();
// No account, no stores, no caps — connecting must not create a user as a side
// effect, or the emulation would arm itself in the background.
expect(getCaps().isEnforcing()).toBe(false);
});
// PER-DOCUMENT INBOXES. Upstream a repo carries `inbox: Option<PrivKey>` and its
// owner records the private half with `AddInboxCap` on the User branch — the same
// branch as `AddLink`. So "which inboxes may I read" has one answer, and connecting
// drains them all: the user's own, and one per document it opened an inbox on.
test("a document has its own inbox: anyone deposits, only the owner reads", async () => {
inject();
setCurrentUser("alice");
const doc = await createEntityDoc("alice", "public");
const docInbox = await documentInbox(doc);
expect(docInbox).not.toBe(await walletInbox("alice"));
// Bob deposits into the document's inbox — the cross-user act, open to all.
setCurrentUser("bob");
await post(docInbox, { payload: { joining: true }, ts: 1 });
// …and cannot read it back: depositing grants nothing.
await expect(readInbox(docInbox)).rejects.toThrow(/does not belong to the connected wallet/i);
// Alice reads her document's inbox, because she opened it.
setCurrentUser("alice");
const deposits = await readInbox(docInbox);
expect(deposits.map((d) => d.payload)).toEqual([{ joining: true }]);
});
test("connecting drains BOTH levels: the user's inbox and its documents'", async () => {
inject();
setCurrentUser("alice");
const protDoc = await createEntityDoc("alice", "protected");
const pubDoc = await createEntityDoc("alice", "public");
const docInbox = await documentInbox(pubDoc);
const aliceInbox = await walletInbox("alice");
// Two deposits, one at each level, both made by someone else.
setCurrentUser("carol");
const carolDoc = await createEntityDoc("carol", "protected");
await shareCap(capFor(carolDoc)!, aliceInbox); // a Link, to alice herself
await post(docInbox, { payload: { onTheDocument: true }, ts: 2 });
// Alice connects: one call, both queues.
setCurrentUser("alice");
await connectedUser();
expect(capFor(carolDoc)).toBeDefined(); // the Link was applied
expect(await readValues([protDoc], SECRET)).toEqual([]); // (protDoc holds no secret here)
const left = await readInbox(docInbox);
expect(left.map((d) => d.payload)).toEqual([{ onTheDocument: true }]); // consumer data stays
});