chore: use package@version tags in release workflow

Author: StephanMeijer

.changeset/README.md

@@ -19,3 +19,5 @@ Publish locally (usually handled by GitHub Actions):
 ```bash
 npm run release
 ```
+
+GitHub Actions creates and pushes `package@version` tags after publish.

.github/workflows/release.yml

@@ -28,13 +28,73 @@ jobs:
         run: npm run build
 
       - name: Create release PR or publish
+        id: changesets
         uses: changesets/action@v1
         with:
           commit: "chore: release packages"
           title: "chore: release packages"
           version: npm run version-packages
           publish: npm run release
+          createGithubReleases: false
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
           NPM_CONFIG_PROVENANCE: true
+
+      - name: Create package@version tags
+        if: steps.changesets.outputs.published == 'true'
+        env:
+          PUBLISHED_PACKAGES: ${{ steps.changesets.outputs.publishedPackages }}
+        run: |
+          node <<'EOF'
+          const { spawnSync } = require("node:child_process");
+
+          const publishedPackages = JSON.parse(process.env.PUBLISHED_PACKAGES || "[]");
+
+          if (!Array.isArray(publishedPackages) || publishedPackages.length === 0) {
+            console.log("No published packages found in Changesets output.");
+            process.exit(0);
+          }
+
+          function run(command, args, options = {}) {
+            const result = spawnSync(command, args, { stdio: "inherit", ...options });
+            if (result.status !== 0) {
+              process.exit(result.status ?? 1);
+            }
+            return result;
+          }
+
+          function localTagExists(tag) {
+            const result = spawnSync("git", ["rev-parse", "-q", "--verify", `refs/tags/${tag}`], {
+              stdio: "ignore",
+            });
+            return result.status === 0;
+          }
+
+          function remoteTagExists(tag) {
+            const result = spawnSync("git", ["ls-remote", "--tags", "origin", `refs/tags/${tag}`], {
+              encoding: "utf8",
+            });
+            if (result.status !== 0) {
+              process.exit(result.status ?? 1);
+            }
+            return result.stdout.trim().length > 0;
+          }
+
+          for (const pkg of publishedPackages) {
+            const tag = `${pkg.name}@${pkg.version}`;
+
+            if (remoteTagExists(tag)) {
+              console.log(`Tag already exists on origin: ${tag}`);
+              continue;
+            }
+
+            if (!localTagExists(tag)) {
+              console.log(`Creating tag: ${tag}`);
+              run("git", ["tag", tag]);
+            }
+
+            console.log(`Pushing tag: ${tag}`);
+            run("git", ["push", "origin", tag]);
+          }
+          EOF

README.md

@@ -32,6 +32,8 @@ This package uses a PR-based release workflow with Changesets. Add a changeset i
 npm run changeset
 ```
 
+Published versions are tagged in Git using the `package@version` pattern (for example, `@typespecs/elixir-ast@0.2.0`).
+
 ## License
 
 [MIT](./LICENSE)

package.json

@@ -22,7 +22,7 @@
     "format": "tsp format lib/**/*.tsp",
     "changeset": "changeset",
     "version-packages": "changeset version",
-    "release": "changeset publish"
+    "release": "changeset publish --no-git-tag"
   },
   "peerDependencies": {
     "@typespec/compiler": "~1.9.0"