Merge pull request 'A provisioner is told what the mesh derived for each consumer (hq ADR 0201, issue 124)' (#10) from feat/a-provider-declares-what-it-derives into main

test/sdk.test.ts

@@ -74,6 +74,55 @@ test("provisioner creates each consumer with the mesh's login and password, remo
   stop();
 });
 
+test("provisioner hands the adapter what the mesh derived, and still has it at withdrawal", async () => {
+  // novox/hq ADR 0201: the provider declares what it derives for each consumer and the mesh fills
+  // it. The adapter must be able to read it on create, must see a changed derivation as a change
+  // worth re-applying, and must still be told it when the consumer is withdrawn — by which time
+  // the mesh has already dropped it from the file.
+  const dir = await mkdtemp(join(tmpdir(), "prov-derived-"));
+  const created: unknown[] = [];
+  const removed: unknown[] = [];
+
+  await writeFile(join(dir, "ncloud.secret"), "minted-pw\n");
+  const receives = join(dir, "store.json");
+  const doc = (given: unknown[]): string =>
+    JSON.stringify({ contributions: 1, requirement: "s3-bucket", given });
+  const entry = (bucket: string) => ({
+    from: "nextcloud", node: "anchor", as: "mesh_anchor_ncloud",
+    secret: join(dir, "ncloud.secret"), values: {}, derived: { bucket },
+  });
+  await writeFile(receives, doc([entry("mesh-anchor-ncloud")]));
+
+  const stop = runProvisioner(
+    "s3-bucket",
+    {
+      async create(p) {
+        created.push(p.derived);
+      },
+      async remove(p) {
+        removed.push(p.derived);
+      },
+    },
+    { receives, everyMs: 20 },
+  );
+
+  await waitFor(() => created.length === 1, 2000);
+  assert.deepEqual(created[0], { bucket: "mesh-anchor-ncloud" });
+
+  // A changed derivation is a changed consumer: the login and the password are the same, and the
+  // resource it is being given is not. Trusted from memory, this would never be applied.
+  await writeFile(receives, doc([entry("mesh-anchor-files")]));
+  await waitFor(() => created.length === 2, 2000);
+  assert.deepEqual(created[1], { bucket: "mesh-anchor-files" });
+
+  // Withdrawn: the file no longer says anything about this consumer, and the adapter is still
+  // told which bucket to take away.
+  await writeFile(receives, doc([]));
+  await waitFor(() => removed.length === 1, 2000);
+  assert.deepEqual(removed[0], { bucket: "mesh-anchor-files" });
+  stop();
+});
+
 test("provisioner applies again what the backend no longer holds, and trusts memory without holds", async () => {
   const dir = await mkdtemp(join(tmpdir(), "prov-holds-"));
   await writeFile(join(dir, "webapp.secret"), "minted-pw\n");