[build] add a daily workflow to update the pinned CDDL specs

.github/workflows/update-cddl.yml

@@ -0,0 +1,81 @@
+name: Update CDDL
+
+on:
+  schedule:
+    - cron: 20 0 * * *
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  update:
+    name: Update CDDL Specs
+    uses: ./.github/workflows/bazel.yml
+    with:
+      name: Update CDDL Specs
+      run: ./go update_cddl
+      artifact-name: cddl-updates
+
+  create-pr:
+    name: Create Pull Request
+    if: github.event.repository.fork == false
+    runs-on: ubuntu-latest
+    needs: update
+    permissions:
+      contents: write
+      pull-requests: write
+      actions: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+      - name: Download patch
+        uses: actions/download-artifact@v8
+        with:
+          pattern: cddl-updates
+          merge-multiple: true
+      - name: Apply patch
+        id: apply
+        run: |
+          if [ -s changes.patch ]; then
+            git apply --index changes.patch
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+          fi
+          rm -f changes.patch
+      - name: Create Pull Request
+        if: steps.apply.outputs.changed == 'true'
+        uses: peter-evans/create-pull-request@v8
+        with:
+          token: ${{ secrets.SELENIUM_CI_TOKEN }}
+          commit-message: "update cddl spec files"
+          author: Selenium CI Bot <selenium-ci@users.noreply.github.com>
+          base: trunk
+          title: "[build] Automated CDDL Spec Update"
+          body: |
+            This is an automated pull request to repin the CDDL grammars and definition
+            indexes from w3c/webref, plus the rendered WebDriver BiDi spec from
+            w3c/webdriver-bidi.
+
+            Auto-generated by the [update-cddl workflow](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})
+          branch: automated-cddl-updates
+          labels: C-build
+
+  on-failure:
+    name: On CDDL Update Failure
+    runs-on: ubuntu-latest
+    needs: [update, create-pr]
+    if: failure() || cancelled()
+    steps:
+      - name: Slack Notification
+        uses: rtCamp/action-slack-notify@v2
+        env:
+          SLACK_ICON_EMOJI: ":rotating_light:"
+          SLACK_COLOR: failure
+          SLACK_CHANNEL: selenium-tlc
+          SLACK_USERNAME: GitHub Workflows
+          SLACK_TITLE: Needs Investigation
+          SLACK_MESSAGE: "Unable to create the daily CDDL Update PR"
+          MSG_MINIMAL: actions url
+          SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK_URL }}

Rakefile

@@ -70,10 +70,19 @@ task :update_multitool do |_task, _arguments|
   Bazel.execute('run', [], '//scripts:update_multitool_binaries')
 end
 
-desc 'Update pinned CDDL spec files from w3c/webref'
+desc 'Update pinned CDDL spec files from w3c/webref and regenerate what they feed'
 task :update_cddl do |_task, _arguments|
   puts 'Updating pinned CDDL spec references'
   Bazel.execute('run', [], '//scripts:update_cddl')
+
+  if SeleniumRake.git.diff('HEAD').path('common/webref_cddl.bzl').none?
+    puts 'Pins unchanged; skipping regeneration'
+    next
+  end
+
+  puts 'Updating the checked-in BiDi schema'
+  Bazel.execute('run', [], '//common/bidi:update-schema')
+  Rake::Task['rb:update_cddl'].invoke
 end
 
 desc 'Update Chrome DevTools support'

common/webref_cddl.bzl

@@ -5,6 +5,7 @@ load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_file")
 # Pinned to a single w3c/webref "main" commit (kept on main so pin-to-pin diffs
 # stay auditable) and regenerated by the //scripts:update_cddl Bazel target:
 # https://github.com/w3c/webref/tree/main/ed/cddl
+# Advanced only when a hash below changes, so it lags main's tip by design.
 _COMMIT = "5e914258243bbca0ccbfe184bdc62eb82d53c6b7"
 _BASE_URL = "https://raw.githubusercontent.com/w3c/webref/{commit}/ed/cddl".format(commit = _COMMIT)
 
@@ -19,8 +20,8 @@ _DFNS_BASE_URL = "https://raw.githubusercontent.com/w3c/webref/{commit}/ed/dfns"
 # snapshot). Only this file carries the readable prose section ids
 # (`#type-`/`#command-`/`#event-`/`#module-`) that webref does not extract; the schema
 # step runs extract_bidi_anchors.mjs over it to build the prose-anchor index. This is a
-# separate repo/branch from the webref pin above, so //scripts:update_cddl repins it to
-# gh-pages' own tip; both track the same editor's draft, within a day of each other.
+# separate repo/branch from the webref pin above, but it only annotates types that come from
+# the CDDL, so //scripts:update_cddl takes gh-pages' tip only when the CDDL content changes.
 _BIDI_SPEC_HTML_COMMIT = "975a118c247b6f0e0b64f8093b5f01238423bab1"
 _BIDI_SPEC_HTML_SHA256 = "ddfc94f2d7692a3da189c997cb3e88388044b661d2459e68cf7a977a11807446"
 _BIDI_SPEC_HTML_URL = "https://raw.githubusercontent.com/w3c/webdriver-bidi/{commit}/index.html".format(

rake_tasks/ruby.rake

@@ -155,6 +155,12 @@ task :install do
   end
 end
 
+desc 'Regenerate the BiDi protocol classes from the pinned CDDL schema'
+task :update_cddl do
+  puts 'Regenerating Ruby BiDi protocol'
+  Bazel.execute('run', [], '//rb/lib/selenium/webdriver:bidi-generate')
+end
+
 desc 'Update Ruby changelog'
 task :changelogs do
   header = "#{ruby_version} (#{Time.now.strftime('%Y-%m-%d')})\n========================="

scripts/update_cddl.py

@@ -17,23 +17,17 @@
 the per-spec ``dfns`` indexes (same webref commit), and the rendered core spec
 HTML pinned from ``w3c/webdriver-bidi``'s ``gh-pages`` branch (its prose section
 anchors are the source of the readable ``#type-``/``#command-`` spec links, and
-that branch is a separate repo, so it is pinned to its own tip). It regenerates:
+that branch is a separate repo, so it is resolved separately). It regenerates:
 
   - ``_COMMIT``, ``_CDDL_FILES``, ``_DFNS_FILES``, and the ``_BIDI_SPEC_HTML_*``
     pins in ``common/webref_cddl.bzl``
   - the matching ``use_repo(...)`` list for the extension in ``MODULE.bazel``
 
------------------------------------------------------------------------------
-usage: update_cddl.py [-h] [--commit COMMIT] [--branch BRANCH]
-
-options:
-  -h, --help       show this help message and exit
-  --commit COMMIT  pin this exact webref commit instead of the branch tip
-  --branch BRANCH  webref branch to resolve when --commit is omitted (default: main)
------------------------------------------------------------------------------
+Nothing is written unless the consumed webref content changed, so both commit pins record
+where the CDDL content last changed rather than the latest tip. The rendered spec is repinned
+in lockstep with the CDDL, since it only annotates types the grammar defines.
 """
 
-import argparse
 import hashlib
 import json
 import os
@@ -46,6 +40,7 @@
 root_dir = Path(os.path.realpath(__file__)).parent.parent
 
 REPO = "w3c/webref"
+BRANCH = "main"
 CDDL_PATH = "ed/cddl"
 DFNS_PATH = "ed/dfns"
 API_HEADERS = {"Accept": "application/vnd.github+json", "User-Agent": "selenium-update-cddl"}
@@ -74,10 +69,6 @@
 MODULE_FILE = root_dir / "MODULE.bazel"
 
 
-def resolve_commit(branch):
-    return resolve_commit_for(REPO, branch)
-
-
 def list_cddl_files(commit):
     r = http.request(
         "GET",
@@ -156,9 +147,18 @@ def sub_once(content, pattern, replacement, where):
     return content
 
 
-def update_pin(commit, cddl_entries, dfns_entries, bidi_commit, bidi_sha256):
-    content = BZL_FILE.read_text()
+def current_bidi_pin(content):
+    commit = re.search(r'_BIDI_SPEC_HTML_COMMIT = "([0-9a-f]+)"', content).group(1)
+    sha256 = re.search(r'_BIDI_SPEC_HTML_SHA256 = "([0-9a-f]+)"', content).group(1)
+    return commit, sha256
+
+
+def drop_commit(content):
+    """Content with the webref commit blanked, so a pin bump alone does not read as a change."""
+    return re.sub(r'(?<![A-Z_])_COMMIT = "[0-9a-f]+"', "", content)
 
+
+def update_pin(content, commit, cddl_entries, dfns_entries, bidi_commit, bidi_sha256):
     # Anchor so this does not also match the tail of `_BIDI_SPEC_HTML_COMMIT = "…"`.
     content = sub_once(content, r'(?<![A-Z_])_COMMIT = "[0-9a-f]+"', f'_COMMIT = "{commit}"', "_COMMIT assignment")
     content = sub_once(
@@ -180,7 +180,7 @@ def update_pin(commit, cddl_entries, dfns_entries, bidi_commit, bidi_sha256):
         "_BIDI_SPEC_HTML_SHA256 assignment",
     )
 
-    BZL_FILE.write_text(content)
+    return content
 
 
 def update_module(repo_names):
@@ -199,19 +199,11 @@ def update_module(repo_names):
 
 
 def main():
-    parser = argparse.ArgumentParser()
-    parser.add_argument("--commit", help="pin this exact webref commit instead of the branch tip")
-    parser.add_argument(
-        "--branch",
-        default="main",
-        help="webref branch to resolve when --commit is omitted (default: main)",
-    )
-    args = parser.parse_args()
-
-    commit = args.commit or resolve_commit(args.branch)
+    commit = resolve_commit_for(REPO, BRANCH)
     print(f"Pinning {REPO}@{commit}")
 
-    before = existing_repo_names(BZL_FILE.read_text())
+    old = BZL_FILE.read_text()
+    before = existing_repo_names(old)
 
     filenames = list_cddl_files(commit)
     print(f"Found {len(filenames)} CDDL files in {CDDL_PATH}")
@@ -220,10 +212,16 @@ def main():
     dfns_entries = build_dfns_entries(commit)
     print(f"Refreshed {len(dfns_entries)} dfns indexes in {DFNS_PATH}")
 
+    # Probe with the pin already in the file so a gh-pages rebuild cannot open the gate.
+    webref_only = update_pin(old, commit, cddl_entries, dfns_entries, *current_bidi_pin(old))
+    if drop_commit(webref_only) == drop_commit(old):
+        print("No pinned spec content changed; leaving the pins at their current commits.")
+        return
+
     bidi_commit, bidi_sha256 = resolve_bidi_spec(BIDI_SPEC_BRANCH)
     print(f"Pinning {BIDI_SPEC_REPO}@{bidi_commit} ({BIDI_SPEC_FILE})")
 
-    update_pin(commit, cddl_entries, dfns_entries, bidi_commit, bidi_sha256)
+    BZL_FILE.write_text(update_pin(old, commit, cddl_entries, dfns_entries, bidi_commit, bidi_sha256))
 
     cddl_names = {name for name, _, _ in cddl_entries}
     repo_names = cddl_names | {name for name, _, _ in dfns_entries} | {BIDI_SPEC_REPO_NAME}