feat(cli): add issue reconciliation scripts and GitHub helper

apps/cli/github.ts

@@ -0,0 +1,93 @@
+/**
+ * GitHub REST plumbing shared by the issue reconcilers (close-solved,
+ * close-topics).
+ *
+ * Importing this module is side-effect free — nothing resolves credentials or
+ * touches the network until github() is awaited — so a script can import it
+ * without inheriting another script's pipeline.
+ *
+ * Repo:  GITHUB_REPOSITORY, else the `origin` remote.
+ * Auth:  GH_TOKEN / GITHUB_TOKEN, else `gh auth token`.
+ */
+import { $ } from "bun";
+import { join } from "node:path";
+
+const ROOT = join(import.meta.dir, "..", "..");
+
+/** Page size used for every list endpoint; also the "more pages" threshold. */
+const PER_PAGE = 100;
+
+export interface GitHub {
+  /** `owner/name`. */
+  repo: string;
+  /** One authenticated request against api.github.com; throws on non-2xx. */
+  api(path: string, init?: RequestInit): Promise<unknown>;
+  /** Every page of a list endpoint, flattened into one stream of elements. */
+  list(path: string): AsyncGenerator<unknown, void, void>;
+  /** Comment on an issue, then close it as completed. */
+  closeIssue(issue: number, comment: string): Promise<void>;
+}
+
+async function resolveRepo(): Promise<string> {
+  if (process.env.GITHUB_REPOSITORY) return process.env.GITHUB_REPOSITORY;
+  const url = (await $`git -C ${ROOT} remote get-url origin`.text()).trim();
+  const m = url.match(/github\.com[:/](.+?)(?:\.git)?$/);
+  if (!m) throw new Error(`cannot derive owner/repo from remote: ${url}`);
+  return m[1]!;
+}
+
+async function resolveToken(): Promise<string> {
+  const env = process.env.GH_TOKEN || process.env.GITHUB_TOKEN;
+  if (env) return env;
+  const token = (await $`gh auth token`.text()).trim();
+  if (!token) throw new Error("no credentials: set GH_TOKEN or run `gh auth login`");
+  return token;
+}
+
+export async function github(): Promise<GitHub> {
+  const repo = await resolveRepo();
+  const token = await resolveToken();
+
+  async function api(path: string, init: RequestInit = {}): Promise<unknown> {
+    const res = await fetch(`https://api.github.com${path}`, {
+      ...init,
+      headers: {
+        accept: "application/vnd.github+json",
+        authorization: `Bearer ${token}`,
+        "x-github-api-version": "2022-11-28",
+        ...(init.body ? { "content-type": "application/json" } : {}),
+      },
+    });
+    if (!res.ok) {
+      throw new Error(`${init.method ?? "GET"} ${path} -> ${res.status} ${await res.text()}`);
+    }
+    return res.json();
+  }
+
+  async function* list(path: string): AsyncGenerator<unknown, void, void> {
+    const sep = path.includes("?") ? "&" : "?";
+    for (let page = 1; ; page++) {
+      const batch = await api(`${path}${sep}per_page=${PER_PAGE}&page=${page}`);
+      if (!Array.isArray(batch)) throw new Error(`unexpected ${path} payload: not an array`);
+      yield* batch;
+      if (batch.length < PER_PAGE) return;
+    }
+  }
+
+  /**
+   * Comment before closing: if the PATCH fails, the issue still carries a
+   * visible note of what the automation decided, instead of failing silently.
+   */
+  async function closeIssue(issue: number, comment: string): Promise<void> {
+    await api(`/repos/${repo}/issues/${issue}/comments`, {
+      method: "POST",
+      body: JSON.stringify({ body: comment }),
+    });
+    await api(`/repos/${repo}/issues/${issue}`, {
+      method: "PATCH",
+      body: JSON.stringify({ state: "closed", state_reason: "completed" }),
+    });
+  }
+
+  return { repo, api, list, closeIssue };
+}