ci: publish a preview of every package on every push

A change to the CLI or a plugin can now be run straight from a branch,
without a release:

    npx https://pkg.pr.new/datocms@<commit-sha> environments:list

Nothing reaches npm, no version is spent, and there is nothing to clean
up afterwards. Also gives `@datocms/cli-utils` the `repository` field it
was missing, which is what pkg.pr.new reads to mint the short URL form —
the other four packages already had one.

Runs only on pushes to branches of this repo, so a fork cannot mint a URL
under our namespace without a maintainer pushing the code first.

Claude-Session: https://claude.ai/code/session_01TbxhxyU1XBsSKtoCJXwAoD

Author: stefanoverna

.github/workflows/continuous-releases.yml

@@ -0,0 +1,44 @@
+# Every commit pushed to a branch of this repo gets an installable preview of
+# every package, without publishing anything to npm:
+#
+#     npx https://pkg.pr.new/datocms@<commit-sha> environments:list
+#
+# The point is to cross a repo boundary while developing. A change here can be
+# tried inside a consumer that lives in another repository — `cms`, a demo, a
+# customer project — from a real tarball, instead of `npm link` or pinning a
+# git branch by hand and remembering to unpin it later. Installing one preview
+# pulls in the previews of its siblings from the same commit, so a change that
+# spans several packages is tried as one coherent set.
+#
+# Pull requests opened from forks are deliberately not published: this runs on
+# pushes to branches of *this* repo, which only people with write access can
+# make, so an unreviewed fork cannot mint a URL under our namespace. If we ever
+# want fork previews too, pkg.pr.new documents an "approved pull requests only"
+# recipe that gates them behind a maintainer's review.
+name: Continuous releases
+
+on:
+  push:
+    # Every branch. Defining `branches` on its own also means tag pushes don't
+    # trigger this, which is what we want: a tag points at a commit that was
+    # already published when it landed on its branch.
+    branches: ["**"]
+
+permissions: {}
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v7
+      - name: Use Node.js
+        uses: actions/setup-node@v7
+        with:
+          node-version-file: .nvmrc
+          cache: "npm"
+      - run: npm ci
+      - run: npm run build
+      # Once for all the packages, not once per package: pkg.pr.new expects a
+      # single invocation per workflow run, and rejects the rest as spam.
+      - run: npm exec -- pkg-pr-new publish --commentWithSha './packages/*'

README.md

@@ -33,6 +33,24 @@ live APIs: they need a `.env` at the root (copy `.env.sample`) and, for
 WordPress, `docker compose up` in `packages/cli-plugin-wordpress`. Each suite
 checks its prerequisites first and tells you which one is missing.
 
+## Trying a change before it's released
+
+Every push to a branch here publishes a preview of all the packages, which you
+can run or install anywhere — no npm release, no `npm link`:
+
+```
+npx https://pkg.pr.new/datocms@<commit-sha> environments:list
+npm i https://pkg.pr.new/@datocms/cli-plugin-wordpress@<commit-sha>
+```
+
+The exact URLs show up in the commit's check run on GitHub, and in a comment on
+the pull request once there is one. Installing one preview pulls in the previews
+of its siblings built from the same commit, so a change spanning several
+packages can be tried as one coherent set.
+
+Previews are throwaway: they are never published to npm, and the URL stops
+resolving after a while. Never commit one to a `package.json` that ships.
+
 ## Releasing
 
 Maintainers only. A release publishes the packages that changed, and gives them

package-lock.json

@@ -30,6 +30,7 @@
     "lint-staged": "^13.1.0",
     "mocha": "^10",
     "oclif": "^4",
+    "pkg-pr-new": "^0.0.88",
     "rimraf": "^3.0.2",
     "ts-node": "^10.2.1",
     "tslib": "^2.3.1",

package.json

@@ -5,6 +5,11 @@
   "author": "Stefano Verna <s.verna@datocms.com>",
   "homepage": "https://github.com/datocms/cli",
   "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/datocms/cli.git",
+    "directory": "packages/cli-utils"
+  },
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
   "directories": {