feat: --json output for release list

src/cli.js

@@ -1,14 +1,14 @@
-// repo-releases CLI: `list <owner/repo> [--fixture path] [--limit N]`.
+// repo-releases CLI: `list <owner/repo> [--fixture path] [--limit N] [--json]`.
 // Uses a local cache over the releases seam; with --fixture it reads a canned
 // upstream response instead of the network (the fast/offline path).
 import { readFileSync } from "node:fs";
 import { rawReleases, parseReleases } from "./github.js";
 import { ReleaseCache } from "./cache.js";
-import { formatTags } from "./format.js";
+import { formatTags, formatJson } from "./format.js";
 
 const cache = new ReleaseCache({ ttlMs: 60_000 });
 
-async function list(slug, { fixture, limit }) {
+async function list(slug, { fixture, limit, json }) {
   const [owner, repo] = String(slug).split("/");
   if (!owner || !repo) throw new Error(`expected <owner/repo>, got "${slug}"`);
   const key = `${owner}/${repo}`;
@@ -20,7 +20,7 @@ async function list(slug, { fixture, limit }) {
     parsed = parseReleases(raw);
     cache.put(key, parsed);
   }
-  return formatTags(parsed, limit);
+  return json ? formatJson(parsed, limit) : formatTags(parsed, limit);
 }
 
 function parseArgs(argv) {
@@ -29,13 +29,14 @@ function parseArgs(argv) {
   for (let i = 0; i < rest.length; i++) {
     if (rest[i] === "--fixture") opts.fixture = rest[++i];
     else if (rest[i] === "--limit") opts.limit = Number(rest[++i]);
+    else if (rest[i] === "--json") opts.json = true;
   }
   return { cmd, slug, opts };
 }
 
 const { cmd, slug, opts } = parseArgs(process.argv.slice(2));
 if (cmd !== "list" || !slug) {
-  process.stderr.write("usage: repo-releases list <owner/repo> [--fixture path] [--limit N]\n");
+  process.stderr.write("usage: repo-releases list <owner/repo> [--fixture path] [--limit N] [--json]\n");
   process.exit(2);
 }
 list(slug, opts)

src/format.js

@@ -1,3 +1,8 @@
+// Render domain releases as a JSON array, newest first, top N (machine-readable).
+export function formatJson(releases, limit = 10) {
+  return JSON.stringify(releases.slice(0, limit), null, 2);
+}
+
 // Render domain releases as aligned "tag  name  date" lines, newest first, top N.
 export function formatTags(releases, limit = 10) {
   const rows = releases.slice(0, limit);

tests/e2e/json.test.js

@@ -0,0 +1,10 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { spawnSync } from "node:child_process";
+
+test("e2e: `list --json` emits valid JSON with the newest tag", () => {
+  const r = spawnSync("node", ["src/cli.js", "list", "cli/cli", "--json", "--fixture", "fixtures/releases.cli-cli.json"], { encoding: "utf8" });
+  assert.equal(r.status, 0, "cli exits 0");
+  const arr = JSON.parse(r.stdout);
+  assert.equal(arr[0].tag, "v2.62.0", "newest tag first");
+});

tests/format.test.js

@@ -1,7 +1,7 @@
 import { test } from "node:test";
 import assert from "node:assert/strict";
 import { parseReleases } from "../src/github.js";
-import { formatTags } from "../src/format.js";
+import { formatTags, formatJson } from "../src/format.js";
 
 test("parse maps real API fields and drops drafts", () => {
   const parsed = parseReleases([
@@ -15,3 +15,8 @@ test("format lists tag and name", () => {
   const out = formatTags([{ tag: "v2", name: "two", publishedAt: "2024-02-01T00:00:00Z" }], 5);
   assert.match(out, /v2\s+two/);
 });
+
+test("formatJson emits a JSON array of {tag,name,publishedAt}", () => {
+  const out = formatJson([{ tag: "v2", name: "two", publishedAt: "2024-02-01T00:00:00Z" }], 5);
+  assert.deepEqual(JSON.parse(out), [{ tag: "v2", name: "two", publishedAt: "2024-02-01T00:00:00Z" }]);
+});