mosquitto: a consumer's grant is the topics it asks for, and its binding says the port

mqtt-topic served nothing: with two listens the mesh could not say which port a consumer dials, so a
consumer had to type 1883 into its config. It now serves the MQTT listener's port (the machine's,
once assigned) and the scheme, so `${bound:mqtt-topic:port}` fills.

The provisioner confined every consumer to `<as>/#`, which leaves nothing for the consumers the
broker exists for: Home Assistant discovers under homeassistant/# and tasmota/discovery/#, and
Node-RED's flows follow the devices' own topics. A consumer now contributes `topics` (MQTT topic
filters) to its mqtt-topic requirement and is granted exactly those; with none, its own subtree as
before. Settings merge into contributions, so an operator narrows a grant per assignment. The role
is brought to exactly the wanted ACLs (stale ones removed), `holds` checks the ACLs too, and an
invalid list is refused, never quietly narrowed. Only the role named for the consumer is touched:
a client carried from the predecessor's password file keeps its own.

modules/mosquitto/test/topics.test.ts

@@ -0,0 +1,72 @@
+// What a consumer of mqtt-topic is granted (topics.ts): its own subtree unless it contributed
+// `topics`; a contributed list is granted exactly, refused whole when it is not topic filters; and
+// the role is brought to exactly the wanted ACLs — missing ones added, stale ones removed — read from
+// `mosquitto_ctrl dynsec getRole` as eclipse-mosquitto 2.1.2 prints it.
+
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { filterProblem, missingAcls, parseRoleAcls, staleAcls, topicFilters, wantedAcls } from "../topics.ts";
+
+test("a consumer that contributed nothing gets its own subtree", () => {
+  assert.deepEqual(topicFilters({}, "mesh_ace_hass"), { ok: true, filters: ["mesh_ace_hass/#"], own: true });
+  assert.deepEqual(topicFilters(undefined, "x"), { ok: true, filters: ["x/#"], own: true });
+  // Settings merge into every contribution: keys that are not `topics` change nothing.
+  assert.deepEqual(topicFilters({ endpoints: { web: {} } }, "x"), { ok: true, filters: ["x/#"], own: true });
+});
+
+test("a contributed list is granted exactly, duplicates once", () => {
+  assert.deepEqual(topicFilters({ topics: ["#"] }, "x"), { ok: true, filters: ["#"], own: false });
+  assert.deepEqual(topicFilters({ topics: ["stat/+/POWER", "tele/#", "tele/#", "/octoprint/x"] }, "x"), {
+    ok: true,
+    filters: ["stat/+/POWER", "tele/#", "/octoprint/x"],
+    own: false,
+  });
+});
+
+test("a list that is not topic filters is refused whole", () => {
+  for (const topics of [[], "#", [""], ["a/#/b"], ["a#"], ["a/b+"], [42], ["a\u0000b"], {}]) {
+    const out = topicFilters({ topics } as Record<string, unknown>, "x");
+    assert.equal(out.ok, false, JSON.stringify(topics));
+  }
+  assert.equal(filterProblem("+/+/#"), undefined);
+  assert.equal(filterProblem("#"), undefined);
+});
+
+const GET_ROLE = `Warning: You are running mosquitto_ctrl without encryption.
+This means all of the configuration changes you are making are visible on the network, including passwords.
+
+Rolename: u1
+ACLs:     publishClientSend    : allow : # (priority: 0)
+          subscribePattern     : allow : u1/# (priority: 0)
+          publishClientReceive : deny : secret topic/with space (priority: -1)
+`;
+
+test("getRole's ACL lines are read, the warning and headings are not", () => {
+  assert.deepEqual(parseRoleAcls(GET_ROLE), [
+    { type: "publishClientSend", allow: true, topic: "#" },
+    { type: "subscribePattern", allow: true, topic: "u1/#" },
+    { type: "publishClientReceive", allow: false, topic: "secret topic/with space" },
+  ]);
+  assert.deepEqual(parseRoleAcls("Rolename: empty\nACLs:\n"), []);
+});
+
+test("the role is brought to exactly the wanted ACLs", () => {
+  const current = parseRoleAcls(GET_ROLE);
+  const wanted = wantedAcls(["u1/#"]);
+  assert.deepEqual(wanted, [
+    { type: "publishClientSend", allow: true, topic: "u1/#" },
+    { type: "publishClientReceive", allow: true, topic: "u1/#" },
+    { type: "subscribePattern", allow: true, topic: "u1/#" },
+  ]);
+  assert.deepEqual(missingAcls(current, wanted), [
+    { type: "publishClientSend", allow: true, topic: "u1/#" },
+    { type: "publishClientReceive", allow: true, topic: "u1/#" },
+  ]);
+  assert.deepEqual(staleAcls(current, wanted), [
+    { type: "publishClientSend", allow: true, topic: "#" },
+    { type: "publishClientReceive", allow: false, topic: "secret topic/with space" },
+  ]);
+  assert.deepEqual(staleAcls(wanted, wanted), []);
+  assert.deepEqual(missingAcls(wanted, wanted), []);
+});