ci: enforce changesets for affected packages on PRs

Author: mgabor3141

.github/scripts/check-changesets.mjs

@@ -0,0 +1,118 @@
+#!/usr/bin/env node
+/**
+ * Verify that every affected publishable package in this PR has at least
+ * one new changeset entry.
+ *
+ * "Affected" = a release-worthy file under `packages/<pkg>/` was added,
+ * modified, renamed, or deleted in the PR diff. Tests, build/test config,
+ * and CHANGELOG.md are excluded since they don't ship to consumers.
+ *
+ * "Covered" = a `.changeset/*.md` file added in this PR has a frontmatter
+ * entry naming the package (any bump level).
+ *
+ * Exits 0 on success, 1 if any affected package is missing a changeset,
+ * 2 on usage/setup error.
+ */
+import { execSync } from "node:child_process";
+import { existsSync, readFileSync, readdirSync } from "node:fs";
+import { join } from "node:path";
+
+const baseSha = process.env.BASE_SHA;
+const headSha = process.env.HEAD_SHA || "HEAD";
+if (!baseSha) {
+	console.error("BASE_SHA env var is required");
+	process.exit(2);
+}
+
+// Make sure we have the base commit locally (shallow clones may lack it).
+try {
+	execSync(`git cat-file -e ${baseSha}^{commit}`, { stdio: "ignore" });
+} catch {
+	execSync(`git fetch --no-tags --depth=1 origin ${baseSha}`, { stdio: "inherit" });
+}
+
+const diffRange = `${baseSha}...${headSha}`;
+const changedFiles = execSync(`git diff --name-only --diff-filter=ACMRTD ${diffRange}`, {
+	encoding: "utf8",
+})
+	.split("\n")
+	.filter(Boolean);
+
+// Discover publishable workspace packages.
+const packagesDir = "packages";
+const pkgNameByDir = new Map();
+for (const entry of readdirSync(packagesDir, { withFileTypes: true })) {
+	if (!entry.isDirectory()) continue;
+	const pjPath = join(packagesDir, entry.name, "package.json");
+	if (!existsSync(pjPath)) continue;
+	const pj = JSON.parse(readFileSync(pjPath, "utf8"));
+	if (pj.private) continue;
+	pkgNameByDir.set(entry.name, pj.name);
+}
+
+/** Return the package name if `file` is release-worthy, else null. */
+function packageForFile(file) {
+	const m = file.match(/^packages\/([^/]+)\/(.+)$/);
+	if (!m) return null;
+	const [, dir, rest] = m;
+	const name = pkgNameByDir.get(dir);
+	if (!name) return null;
+	// Excluded: tests, build/test config, generated CHANGELOG.
+	if (/(^|\/)(test|tests|__tests__)\//.test(rest)) return null;
+	if (/\.test\.[jt]sx?$/.test(rest)) return null;
+	if (/^(tsup\.config|vitest\.config|tsconfig|biome)\b/.test(rest)) return null;
+	if (rest === "CHANGELOG.md") return null;
+	return name;
+}
+
+const affected = new Set();
+for (const f of changedFiles) {
+	const name = packageForFile(f);
+	if (name) affected.add(name);
+}
+
+// Collect packages covered by changeset files *added* in this PR.
+const addedChangesetFiles = execSync(
+	`git diff --name-only --diff-filter=A ${diffRange} -- ".changeset/*.md"`,
+	{ encoding: "utf8" },
+)
+	.split("\n")
+	.filter(Boolean)
+	.filter((f) => !f.endsWith("README.md"));
+
+const covered = new Set();
+for (const file of addedChangesetFiles) {
+	// Read from the head ref so the script works even if the file has
+	// already been consumed by a later `changeset version` run.
+	const text = execSync(`git show ${headSha}:${file}`, { encoding: "utf8" });
+	const fm = text.match(/^---\s*\n([\s\S]*?)\n---/);
+	if (!fm) continue;
+	for (const line of fm[1].split("\n")) {
+		// Match `"@scope/name": patch` or `name: minor` etc.
+		const m = line.match(/^\s*["']?([^"'\s:]+)["']?\s*:\s*(patch|minor|major)\s*$/);
+		if (m) covered.add(m[1]);
+	}
+}
+
+const missing = [...affected].filter((p) => !covered.has(p)).sort();
+
+if (affected.size === 0) {
+	console.log("No publishable package files changed; no changeset required.");
+	process.exit(0);
+}
+
+console.log(`Affected packages (${affected.size}): ${[...affected].sort().join(", ")}`);
+console.log(`Covered by new changesets (${covered.size}): ${[...covered].sort().join(", ") || "(none)"}`);
+
+if (missing.length === 0) {
+	console.log("✓ All affected packages have a changeset.");
+	process.exit(0);
+}
+
+console.error("");
+console.error("✗ Missing changeset entries for:");
+for (const p of missing) console.error(`  - ${p}`);
+console.error("");
+console.error("Run `yarn changeset` locally, pick the affected packages, and commit");
+console.error("the resulting file under .changeset/.");
+process.exit(1);

.github/workflows/changeset-check.yml

@@ -0,0 +1,25 @@
+name: Changeset check
+
+on:
+  pull_request:
+    branches: [main]
+
+jobs:
+  changeset:
+    # Skip the auto-generated release PR opened by the changesets action.
+    if: ${{ !startsWith(github.head_ref, 'changeset-release/') }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+
+      - name: Verify changesets cover affected packages
+        env:
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+        run: node .github/scripts/check-changesets.mjs