gitea: a merge poll looks only at repositories that moved, one pass at a time

With the poll the only announcer of a merge, its cost showed: every 30 s it
asked every repository for its pull requests, a pass outlasted the tick, and
passes piled up beside each other — a merge was announced four and a half
minutes late, and two passes at once could each announce it. A pass now asks
only repositories updated since a minute before the last look, and the next
pass starts when this one ends. hq issue 250.

modules/gitea/client.ts

@@ -17,6 +17,8 @@ export interface GiteaRepo {
   description?: string;
   html_url: string;
   default_branch?: string;
+  /** When anything last moved in it — a push, and so a merge. */
+  updated_at?: string;
 }
 
 /** An issue, with its labels flattened to names. */
@@ -356,6 +358,7 @@ export class GiteaClient {
       description: r.description || undefined,
       html_url: r.html_url,
       default_branch: r.default_branch,
+      updated_at: r.updated_at ?? undefined,
     };
   }
 
@@ -598,3 +601,11 @@ export class GiteaAdmin {
     GiteaAdmin.fail(`/admin/users/${username}`, res);
   }
 }
+
+/** The repositories that moved at or after a moment: every one when there is no moment yet, and one whose
+ *  update time is not known, so a forge that does not say is asked as before (novox/hq issue 250). */
+export function movedSince(repos: GiteaRepo[], floor: string): GiteaRepo[] {
+  if (!floor) return repos;
+  const at = Date.parse(floor);
+  return repos.filter((r) => !r.updated_at || !(Date.parse(r.updated_at) < at));
+}

modules/gitea/index.ts

@@ -14,7 +14,7 @@
 // the forge for an immediacy nobody asked for is not.
 
 import { emit } from "@novox/mesh-sdk/events";
-import { GiteaClient } from "./client.js";
+import { GiteaClient, movedSince } from "./client.js";
 
 // Without a way to a token — configured, or mintable with the admin account (token.ts) — there is
 // nothing to watch; log and stay quiet rather than crash the runtime. With one, the first poll mints
@@ -84,8 +84,16 @@ function keepAnnounced(): void {
   writeFileSync(tmp, JSON.stringify({ announced: [...announced].slice(-2000), since }));
   renameSync(tmp, mergedRecord);
 }
+// **Only the repositories that moved** (novox/hq issue 250). A merge is a push, and a push moves the
+// repository's update time; asking every repository for its pull requests on every tick took longer than the
+// tick itself, so ticks piled up and a merge was announced minutes late. A repository unchanged since a
+// minute before the last look is skipped — the minute absorbs the forge's clock against this one.
+let lastLook = "";
+const MARGIN_MS = 60_000;
 async function pollMerged(client: GiteaClient): Promise<void> {
-  const repos = await client.listAllRepos();
+  const began = new Date().toISOString();
+  const floor = lastLook && primedMerges ? new Date(Date.parse(lastLook) - MARGIN_MS).toISOString() : "";
+  const repos = movedSince(await client.listAllRepos(), floor);
   let changed = false;
   for (const repo of repos) {
     const pulls = await client.listPullRequests(repo.owner, repo.name, { state: "closed", sort: "recentupdate", limit: "20" });
@@ -124,6 +132,7 @@ async function pollMerged(client: GiteaClient): Promise<void> {
   if (!primedMerges) since = new Date().toISOString();
   if (!primedMerges || changed) keepAnnounced();
   primedMerges = true;
+  lastLook = began;
 }
 
 if (gitea) {
@@ -132,6 +141,9 @@ if (gitea) {
   // yet, the admin account refused on a restored forge) is one fact, and a recovery is worth a line.
   let failing: string | null = null;
   const tick = (fn: () => Promise<void>, everyMs: number): void => {
+    // **One pass at a time** (novox/hq issue 250): the next pass is scheduled when this one has ended, so a
+    // pass that outlasts its interval delays the next instead of running beside it — two passes at once
+    // could each announce the same merge before either recorded it.
     const run = (): void =>
       void fn()
         .then(() => {
@@ -142,8 +154,8 @@ if (gitea) {
           const why = err instanceof Error ? err.message : String(err);
           if (why !== failing) console.error(`[gitea] not watching until this clears — ${why}`);
           failing = why;
-        });
-    setInterval(run, everyMs);
+        })
+        .finally(() => setTimeout(run, everyMs));
     run();
   };
   tick(() => pollRepos(client), 60_000);

modules/gitea/test/pages.test.ts

@@ -22,3 +22,15 @@ test("every page of a pull request's files is read, though the forge caps a page
   assert.equal(got.truncated, false);
   assert.equal(new Set(got.paths).size, total);
 });
+
+test("a pass asks only the repositories that moved since the last look, every one before the first", async () => {
+  const { movedSince } = await import("../client.ts");
+  const repos = [
+    { full_name: "a/old", name: "old", owner: "a", private: false, html_url: "", updated_at: "2026-10-05T10:00:00Z" },
+    { full_name: "a/new", name: "new", owner: "a", private: false, html_url: "", updated_at: "2026-10-05T16:10:02Z" },
+    { full_name: "a/unknown", name: "unknown", owner: "a", private: false, html_url: "" },
+  ];
+  assert.deepEqual(movedSince(repos, "").map((r) => r.name), ["old", "new", "unknown"]);
+  assert.deepEqual(movedSince(repos, "2026-10-05T16:09:00.000Z").map((r) => r.name), ["new", "unknown"]);
+  assert.deepEqual(movedSince(repos, "2026-10-05T18:10:02+02:00").map((r) => r.name), ["new", "unknown"], "an offset is a moment, not a string");
+});