chore: add a release automation script

2026-08-30 16:59:56 +00:00 · 2026-08-27 17:07:32 -07:00
parent 29afac60f6
commit c97e5c6f72
5 changed files with 157 additions and 2 deletions
@@ -0,0 +1,104 @@
+import { execFileSync } from "node:child_process";
+import { readFileSync, writeFileSync } from "node:fs";
+
+type Section = {
+  body: string;
+  start: number;
+  title: string;
+};
+
+const CHANGELOG = new URL("../CHANGELOG.md", import.meta.url);
+const PACKAGE = new URL("../package.json", import.meta.url);
+const SEMVER = /^\d+\.\d+\.\d+(?:-[0-9A-Za-z.]+)?$/;
+const BETA = "> This is a beta release. Please report any issues you encounter.";
+
+function die(message: string): never {
+  console.error(`release: ${message}`);
+  process.exit(1);
+}
+
+function git(...args: string[]) {
+  try {
+    return execFileSync("git", args, {
+      encoding: "utf8",
+      stdio: ["ignore", "pipe", "inherit"],
+    }).trim();
+  } catch {
+    die(`git ${args.join(" ")} failed`);
+  }
+}
+
+function readSections(text: string): Section[] {
+  const heads = [...text.matchAll(/^# (.+)$/gm)];
+  if (heads.length === 0) die("CHANGELOG.md has no sections");
+
+  return heads.map((head, index) => ({
+    body: text.slice(head.index + head[0].length, heads[index + 1]?.index),
+    start: head.index,
+    title: head[1],
+  }));
+}
+
+function cut(version: string) {
+  if (!SEMVER.test(version)) die(`\`${version}\` is not a version`);
+
+  const tag = `v${version}`;
+  if (git("status", "--porcelain", "--untracked-files=no")) die("the working tree is dirty");
+  if (git("tag", "--list", tag)) die(`${tag} already exists`);
+
+  const text = readFileSync(CHANGELOG, "utf8");
+  const [next, ...released] = readSections(text);
+  if (next.title !== "Next") die("CHANGELOG.md must open with a `# Next` section");
+
+  const notes = next.body.trim();
+  if (!notes) die("`# Next` is empty");
+
+  const date = new Date().toLocaleDateString("en-US", {
+    month: "long",
+    day: "numeric",
+    year: "numeric",
+  });
+
+  const beta = version.includes("-") ? `${BETA}\n\n` : "";
+  const section = `# ${version} (${date})\n\n${beta}${notes}\n\n---\n\n`;
+  writeFileSync(CHANGELOG, `# Next\n\n${section}${text.slice(released[0].start)}`);
+
+  const pkg = readFileSync(PACKAGE, "utf8");
+  const bumped = pkg.replace(/^(\s*"version": ")[^"]+(",)$/m, `$1${version}$2`);
+  if (bumped === pkg) die("could not find the version field in package.json");
+  writeFileSync(PACKAGE, bumped);
+
+  git("add", "CHANGELOG.md", "package.json");
+  git("commit", "-m", `chore: ${tag}`);
+  git("tag", "-m", tag, tag);
+
+  console.log(`${tag} is committed and tagged. To ship it:\n`);
+  console.log("  git push origin main --follow-tags");
+}
+
+function notes(tag?: string) {
+  const text = readFileSync(CHANGELOG, "utf8");
+  const section = readSections(text).find((entry) => /^\d/.test(entry.title));
+  if (!section) die("CHANGELOG.md has no released version");
+
+  const version = section.title.split(" ")[0];
+  if (tag && tag !== `v${version}`) die(`${tag} is not the top section (${version})`);
+
+  console.log(section.body.replace(/---\s*$/, "").trim());
+}
+
+const [command, argument] = process.argv.slice(2);
+
+switch (command) {
+  case "cut":
+    if (!argument) die("usage: release.ts cut <version>");
+    cut(argument);
+    break;
+
+  case "notes":
+    notes(argument);
+    break;
+
+  default:
+    die("usage: release.ts <cut|notes> [tag]");
+}