Merge pull request 'Serve a seat's verbs from the membership once one is issued (hq issue 218)' (#45) from fix/issue-218-the-membership-decides-the-seats into main

node-tools/src/runtime.ts

@@ -342,13 +342,16 @@ async function serveClaimedSeats(
     for (const module of served) {
       const m = typeof broker.membership === "function" ? broker.membership(module) : undefined;
       for (const s of m?.seats ?? []) add({ seat: s.seat, verb: s.verb, subject: s.subject, holder: module });
-      // The credential's claims, for the module's own runtime: where the mesh issued the verb when
+      // The credential's claims, for the module's own runtime, ONLY until the mesh issues a
-      // it has; the derived shape until then.
+      // membership (novox/hq issue 218). The credential names what the module claims; the membership
-      if (module !== self) continue;
+      // names what it holds on this machine. A seat held once for the mesh is claimed by every
+      // machine running the module and held by one, so once a membership exists it decides: a claim
+      // it leaves out is not held here, and serving it anyway announced the seat from a machine the
+      // bus then refused it on.
+      if (module !== self || m) continue;
       for (const claim of credential?.claims ?? []) {
         for (const verb of claim.serves ?? []) {
-          const subject = m?.seats?.find((s) => s.seat === claim.seat && s.verb === verb)?.subject
+          const subject = seatToolSubject(claim.seat, verb, claim.scope, credential?.node);
-            ?? seatToolSubject(claim.seat, verb, claim.scope, credential?.node);
           add({ seat: claim.seat, verb, subject, holder: module });
         }
       }

node-tools/test/fixtures/store-claimant.mjs

@@ -0,0 +1,13 @@
+// A copy for the issue 218 test: a fixture registers once per process, at import.
+// A module that is both software and a role: postgres's own tools under its name, and its
+// implementation of the mesh-store seat's verbs under the seat's (novox/hq ADR 0159, 0160).
+import { registerModuleTools } from "@novox/mesh-sdk/tools";
+
+registerModuleTools("postgres", () => [
+  { name: "postgres_create_database", description: "make one", input: {}, run: async () => ({ made: true }) },
+  { name: "databases", description: "postgres's own listing", input: {}, run: async () => ({ software: "postgres" }) },
+]);
+
+registerModuleTools("mesh-store", () => [
+  { name: "databases", description: "what the store holds", input: {}, run: async () => ({ seat: "mesh-store" }) },
+]);

node-tools/test/membership.test.ts

@@ -140,6 +140,36 @@ test("a seat's verbs are implemented under the seat's name, served where issued,
   }
 });
 
+// novox/hq issue 218: the store seat is claimed by every machine running postgres and held by one.
+// Where the mesh issued a membership without the seat, the claim in the credential serves nothing:
+// the module's own tools answer, the seat's verbs do not, and the runtime does not announce them.
+test("a claimant the membership does not make the holder serves none of the seat's verbs", async (t) => {
+  if (!url) return t.skip("MESH_TEST_NATS unset");
+  resetTools();
+  const stream = await anAssignmentsStream();
+  await stream.issue({
+    node: "elsewhere",
+    module: "postgres",
+    serves: [{ subject: "mesh.mod.postgres.tool.{tool}.elsewhere" }],
+    emits: "mesh.mod.postgres.event.{event}",
+    tools: "mesh.mod.postgres.tool.tools",
+  });
+  const credential = { url, node: "elsewhere", module: "postgres", claims: [{ seat: "mesh-store", scope: "mesh", serves: ["databases", "query"] }] };
+  const pg = await connectNats(credential);
+  const asker = await connectNats({ url, module: "console", node: "workstation" });
+  let stop = () => {};
+  try {
+    stop = await runTools({ broker: pg, credential, moduleEntrypoints: [fixture("store-claimant.mjs")] });
+    assert.deepEqual((await callTool(asker, "postgres.databases@elsewhere", {})).result, { software: "postgres" });
+    await assert.rejects(callTool(asker, "seat:mesh-store.databases", {}), /no responders|503/i, "the store is not held here");
+  } finally {
+    stop();
+    await asker.close();
+    await pg.close();
+    await stream.close();
+  }
+});
+
 test("a module named like its seat registers once, and answers as the module and as the seat", async (t) => {
   if (!url) return t.skip("MESH_TEST_NATS unset");
   resetTools();