Add a release script for lockstep version bumps

scripts/release.mjs sets every packages/* and compat/* package to a new version in lockstep (explicit x.y.z or a patch/minor/major bump), refusing to run if they are not already in sync. Inter-package and shim deps use pnpm workspace:*, rewritten to the exact version at publish, so only each package's own version field changes. Wired as `npm run release`.

Author: MesTTo

package.json

@@ -9,6 +9,7 @@
   },
   "scripts": {
     "build": "pnpm -r build",
+    "release": "node scripts/release.mjs",
     "test": "vitest run",
     "test:watch": "vitest",
     "typecheck": "pnpm -r --filter \"./packages/*\" --filter \"./compat/*\" exec tsc --noEmit",

scripts/release.mjs

@@ -0,0 +1,75 @@
+// SPDX-FileCopyrightText: 2026 MesTTo
+// SPDX-License-Identifier: MIT
+
+// Bump every publishable package to a new version in lockstep. A MeTTaScript release versions all of
+// packages/* and compat/* together; their inter-package and shim dependencies use pnpm `workspace:*`,
+// which `pnpm publish` rewrites to the exact version, so only each package's own `version` field changes
+// here. The private root package carries no version and is left untouched.
+//
+// Usage:
+//   node scripts/release.mjs 2.5.1          set an explicit version
+//   node scripts/release.mjs patch          bump the shared patch version (also: minor, major)
+//   npm run release -- patch                same, via the package script
+//
+// After bumping: add the RELEASE_NOTES.md section, commit as "MeTTaScript <version>", tag `v<version>`,
+// and push the commit and tag. `.github/workflows/release.yml` builds and publishes on the pushed `v*` tag.
+
+import { readFileSync, writeFileSync, readdirSync, existsSync } from "node:fs";
+import { join, dirname } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const root = join(dirname(fileURLToPath(import.meta.url)), "..");
+
+/** Every publishable package.json under packages/* and compat/*. */
+function packageManifests() {
+  return ["packages", "compat"].flatMap((base) => {
+    const dir = join(root, base);
+    if (!existsSync(dir)) return [];
+    return readdirSync(dir, { withFileTypes: true })
+      .filter((entry) => entry.isDirectory())
+      .map((entry) => join(dir, entry.name, "package.json"))
+      .filter(existsSync);
+  });
+}
+
+/** The target version for an explicit `x.y.z` (optionally with a prerelease suffix) or a semver bump keyword. */
+function nextVersion(current, spec) {
+  if (/^\d+\.\d+\.\d+(-[0-9A-Za-z.]+)?$/.test(spec)) return spec;
+  const [major, minor, patch] = current.split(".").map((n) => Number.parseInt(n, 10));
+  if (spec === "major") return `${major + 1}.0.0`;
+  if (spec === "minor") return `${major}.${minor + 1}.0`;
+  if (spec === "patch") return `${major}.${minor}.${patch + 1}`;
+  return undefined;
+}
+
+function fail(message) {
+  console.error(message);
+  process.exit(1);
+}
+
+const spec = process.argv[2];
+if (spec === undefined) fail("usage: node scripts/release.mjs <version | patch | minor | major>");
+
+const manifests = packageManifests();
+if (manifests.length === 0) fail("no publishable packages found under packages/ or compat/");
+
+const current = new Set(manifests.map((file) => JSON.parse(readFileSync(file, "utf8")).version));
+if (current.size !== 1)
+  fail(`packages are not in lockstep, refusing to bump: ${[...current].sort().join(", ")}`);
+const from = [...current][0];
+
+const to = nextVersion(from, spec);
+if (to === undefined) fail(`not a version or a patch/minor/major bump: ${spec}`);
+if (to === from) fail(`already at ${to}`);
+
+for (const file of manifests) {
+  const text = readFileSync(file, "utf8");
+  // Replace only the package's own top-level version field. `workspace:*` dependencies carry no literal
+  // version, so this string is unambiguous and formatting (indentation, key order) is preserved.
+  const bumped = text.replace(/"version":\s*"[^"]+"/, `"version": "${to}"`);
+  if (bumped === text) fail(`no version field in ${file}`);
+  writeFileSync(file, bumped);
+}
+
+console.log(`bumped ${manifests.length} packages: ${from} -> ${to}`);
+console.log(`next: update RELEASE_NOTES.md, commit "MeTTaScript ${to}", tag v${to}, push commit + tag`);