ng-eventually/packages/polyfill/test/listing-surfaces-failure.test.ts

/**
 * `listMyEntityDocs` answers a VERIFIED listing, or it surfaces — never a half-truth.
 *
 * The call stands on two reads of the same store document, one behind the other: the Main
 * branch says WHICH documents are in there, the Store branch hands back the KEY of each
 * (the emulated `AddRepo { read_cap }`). Both have to answer for the array it returns to
 * mean what a caller reads into it — *these are your documents, here they are*.
 *
 * Neither failure is visible from the outside, and that is the whole reason this file
 * exists. A listing whose keys never arrived is the SAME `Nuri[]` as one whose keys did:
 * the caller learns nothing at the call, and finds out at the next read, which comes back
 * empty with the cause long gone. An empty listing over a store that did not answer is
 * worse still — it says "you created nothing", and an application renders that.
 *
 * That is the shape this library shipped twice already: `resolveAccount` answering "no such
 * account" for a read that FAILED (`8c8ade7`), and `connectedUser` resolving over a restore
 * that never ran (`f6d1734`, which reached a consuming application). The listing was the
 * last member of the family, tolerated on the argument that this caller already holds the
 * array by the time the key read fails — which is exactly what makes returning it a lie
 * rather than a shortcut.
 *
 * ── The fault is the broker's, and it is one a real one produces ──────────
 * The two reads are two round-trips. Between them the connection can die — that is all
 * that is simulated here: the broker answers normally, then stops answering, and every
 * later query rejects the way the wasm binding rejects a `RepoNotFound`/transport error.
 * Nothing reaches into the library to make one of its functions throw artificially, and
 * nothing plants a state the wallet could not be in: the documents below were CREATED
 * through the surface, over the same wallet, in the session before.
 */

import { test, expect, describe, mock, beforeEach } from "bun:test";
import { makeUseShapeHook } from "./use-shape-fake";
import { configure, storeRegistry, docs } from "../src/index";
import { configureStoreRegistry } from "../src/shared-wallet/bootstrap";
import { sparqlUpdate } from "../src/surface/docs";
import type { NgLike, Nuri, StoreType, UseShapeLike } from "../src/model/types";
import { listMyEntityDocs } from "../src/shared-wallet/account-registry";
import { SESSION, forgetEverything, makeWallet, signIn, storeOfType, type Quad } from "./wallet-fake";

const SHIM = "urn:ng-eventually:shim";
/** The Main-branch read — "which documents are in this store". */
const LISTING_READ = `<${SHIM}:contains>`;
/** The Store-branch read — "and what is the key of each". */
const KEY_READ = `<${SHIM}:readCap>`;

const TITLE = "urn:test:title";

/**
 * The titles `doc` carries, read the way an APPLICATION reads one document since
 * `1.0.0-dev.8`: the published anchored `docs.sparqlQuery`, naming the document. It
 * replaces `readUnion([doc])`, which was the same anchored query with a batch around it.
 */
async function titlesIn(doc: Nuri): Promise<string[]> {
  const res = await docs.sparqlQuery(
    SESSION.sessionId,
    "SELECT ?s ?p ?o WHERE { ?s ?p ?o }",
    undefined,
    doc,
    "readDoc",
  );
  const rows = (res as { results?: { bindings?: Array<Record<string, { value: string }>> } })
    .results?.bindings ?? [];
  return rows.filter((r) => r["p"]?.value === TITLE).map((r) => r["o"]!.value);
}


/**
 * Wire the library onto `quads` over a broker that STOPS ANSWERING from the first query
 * `lostAt` accepts — that one included, and every one after it, for the rest of the page.
 *
 * A dropped connection is not selective, so neither is this: the switch decides *when* the
 * link dies, never *which* call is unlucky. Passing `() => false` is a broker that stays up.
 */
function bootPage(quads: Quad[], lostAt: (query: string) => boolean): void {
  const wallet = makeWallet(quads);
  let lost = false;
  const ng = {
    doc_create: wallet.doc_create,
    sparql_update: wallet.sparql_update,
    sparql_query: mock(async (...a: unknown[]) => {
      if (lost || lostAt(a[1] as string)) {
        lost = true;
        throw new Error("BrokerError: connection lost");
      }
      return wallet.sparql_query(...a);
    }),
  };
  configure({ ng: ng as unknown as NgLike, useShape: makeUseShapeHook().hook });
  configureStoreRegistry({ getSession: async () => SESSION, normalizeId: (id) => id.trim() });
}

/**
 * The session before: alice signs in and creates one document, over a broker that works.
 *
 * Returns the reference she keeps, and the quads the wallet now holds — the durable half
 * that outlives the page.
 */
async function aFirstSessionThatCreated(scope: StoreType): Promise<{ quads: Quad[]; note: Nuri }> {
  const quads: Quad[] = [];
  forgetEverything();
  bootPage(quads, () => false);
  await signIn("alice");
  const note = await storeRegistry.createEntityDoc(await storeOfType(scope));
  await sparqlUpdate(
    SESSION.sessionId,
    `INSERT DATA { <urn:test:note> <${TITLE}> "the note" }`,
    note,
  );
  return { quads, note };
}

/**
 * The page comes back over the same wallet and alice signs in — and only THEN does the link
 * die, on `read`. Signing in succeeds, so the failure lands inside the one call under test
 * rather than upstream of it, which is what makes the assertion about `listMyEntityDocs`.
 */
async function aSecondSessionLosingTheBrokerOn(quads: Quad[], read: string): Promise<void> {
  let armed = false;
  forgetEverything();
  bootPage(quads, (query) => armed && query.includes(read));
  await signIn("alice");
  armed = true;
}

const ALL_SCOPES: StoreType[] = ["public", "protected", "private"];

beforeEach(() => {
  forgetEverything();
});

describe("listMyEntityDocs answers a verified listing or surfaces", () => {
  // The NORMAL case first, and it is not a formality: a call that threw unconditionally
  // would pass both failure branches below. This is what the two of them are a departure
  // from — the listing answers, and every document it names opens.
  for (const scope of ALL_SCOPES) {
    test(`[${scope}] a broker that answers gives a listing whose documents open`, async () => {
      const { quads, note } = await aFirstSessionThatCreated(scope);

      forgetEverything();
      bootPage(quads, () => false);
      await signIn("alice");

      expect(await listMyEntityDocs("alice", scope)).toContain(note);
      // Read the way an application reads one document now that `readUnion` is gone: the
      // published anchored query, naming the document it was just handed.
      expect(await titlesIn(note)).toEqual(["the note"]);
    });
  }

  // The tolerance this file was written to remove: the listing is IN HAND when the key read
  // fails, so returning it costs the library nothing and tells the caller something false.
  for (const scope of ALL_SCOPES) {
    test(`[${scope}] the keys not answering surfaces, instead of a keyless listing`, async () => {
      const { quads, note } = await aFirstSessionThatCreated(scope);
      await aSecondSessionLosingTheBrokerOn(quads, KEY_READ);

      await expect(listMyEntityDocs("alice", scope)).rejects.toThrow(/BrokerError/);
      // And the point of the refusal, stated as the caller sees it: nothing came back that
      // could be mistaken for "here are your documents".
      const answered = await listMyEntityDocs("alice", scope).catch(() => null);
      expect(answered).toBeNull();
      expect(answered).not.toEqual([note]);
    });
  }

  // The other half of the same promise, and the more dangerous value of the two: an empty
  // array reads as "this account created nothing", which an application renders as an
  // empty screen rather than as a breakdown.
  for (const scope of ALL_SCOPES) {
    test(`[${scope}] the listing itself not answering surfaces, instead of "you own nothing"`, async () => {
      const { quads } = await aFirstSessionThatCreated(scope);
      await aSecondSessionLosingTheBrokerOn(quads, LISTING_READ);

      await expect(listMyEntityDocs("alice", scope)).rejects.toThrow(/BrokerError/);
      const answered = await listMyEntityDocs("alice", scope).catch(() => null);
      expect(answered).toBeNull();
      expect(answered).not.toEqual([]);
    });
  }
});