feat(cli): add completion helper and handle review issue releases/closures

apps/cli/topics.ts

@@ -25,12 +25,13 @@
 import type { Problem } from "../api/src/reviews.ts";
 import type { GitHub } from "./github.ts";
 
+/** Completion of a required set: a topic's core problems, or every problem of a review. */
 export interface Core {
-  /** Core sub-issues, closed and open alike, lowest number first. */
+  /** The required problems, closed and open alike, in the order given. */
   all: number[];
-  /** The core sub-issues still open — non-empty means the topic stays open. */
+  /** The required problems still open — non-empty means the issue stays open. */
   pending: number[];
-  /** When the last core sub-issue closed; null until the topic is finished. */
+  /** When the last required problem closed; null until the set is finished (never, if empty). */
   finishedAt: string | null;
 }
 
@@ -71,13 +72,18 @@ export function labelValue(problem: Problem, prefix: string): string | undefined
   return problem.labels.find((l) => l.startsWith(prefix))?.slice(prefix.length);
 }
 
+/** A topic's rule: its `set:core` problems are the required set. */
 export function coreSet(problems: Problem[]): Core {
-  const core = problems.filter((p) => labelValue(p, "set:") === "core");
-  const pending = core.filter((p) => !p.closedAt).map((p) => p.number);
+  return completion(problems.filter((p) => labelValue(p, "set:") === "core"));
+}
+
+/** The shared rule: finished when non-empty and every required problem is closed. */
+export function completion(required: Problem[]): Core {
+  const pending = required.filter((p) => !p.closedAt).map((p) => p.number);
   // ISO instants from the API share one format, so string order is time order.
   const finishedAt =
-    core.length && !pending.length
-      ? core.map((p) => p.closedAt!).reduce((a, b) => (a > b ? a : b))
+    required.length && !pending.length
+      ? required.map((p) => p.closedAt!).reduce((a, b) => (a > b ? a : b))
       : null;
-  return { all: core.map((p) => p.number), pending, finishedAt };
+  return { all: required.map((p) => p.number), pending, finishedAt };
 }