ci: Add CI step to check for draftlog

.github/PULL_REQUEST_TEMPLATE.md

@@ -18,5 +18,5 @@ Before opening a pull request, developer should:
 7. select the _Allow edits from maintainers_ option (see this [article](https://help.github.com/articles/allowing-changes-to-a-pull-request-branch-created-from-a-fork/) for more details).
 
 After opening a pull request, developer:
- - should create a new small markdown log file using the PR number e.g. `1010_fix.md` or `1010_add.md` inside `draftlogs` folder as described in this [README](https://github.com/plotly/plotly.js/blob/master/draftlogs/README.md), commit it and push.
+ - should create a new small markdown log file using the PR number e.g. `1010_fix.md` or `1010_add.md` inside `draftlogs` folder as described in this [README](https://github.com/plotly/plotly.js/blob/master/draftlogs/README.md), commit it and push. A CI check enforces this; PRs that don't warrant a CHANGELOG entry can opt out by applying the `no-draftlog` label.
  - should **not** force push (i.e. `git push -f`) to remote branches associated with opened pull requests. Force pushes make it hard for maintainers to keep track of updates. Therefore, if required, please fetch `upstream/master` and "merge" with master instead of "rebase".

.github/workflows/check-draftlog.yml

@@ -0,0 +1,77 @@
+name: Check Draftlog
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize, labeled, unlabeled, ready_for_review]
+
+concurrency:
+  group: check-draftlog-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  check-draftlog:
+    if: github.event.pull_request.draft == false
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          fetch-depth: 0
+
+      - name: Check for a new draftlog entry
+        env:
+          PR_LABELS: ${{ toJson(github.event.pull_request.labels.*.name) }}
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
+        run: |
+          set -euo pipefail
+
+          if echo "$PR_LABELS" | grep -q '"no-draftlog"'; then
+            echo "Skipping draftlog check: 'no-draftlog' label is set."
+            exit 0
+          fi
+
+          ADDED=$(git diff --name-only --diff-filter=A "$BASE_SHA"...HEAD -- 'draftlogs/*.md' | grep -v '^draftlogs/README\.md$' || true)
+
+          if [ -z "$ADDED" ]; then
+            echo "::error::No new draftlog entry was added under draftlogs/."
+            echo ""
+            echo "Most PRs should add a markdown file under draftlogs/ for the next CHANGELOG."
+            echo "See draftlogs/README.md for the filename convention."
+            echo ""
+            echo "If this PR genuinely does not need a changelog entry (e.g. CI-only,"
+            echo "internal refactor, docs typo), add the 'no-draftlog' label to this PR."
+            exit 1
+          fi
+
+          INVALID_NAMES=$(echo "$ADDED" | grep -vE '^draftlogs/[0-9]+_(fix|add|remove|change|deprecate)\.md$' || true)
+          if [ -n "$INVALID_NAMES" ]; then
+            echo "::error::Invalid draftlog filename(s):"
+            echo "$INVALID_NAMES" | sed 's/^/  - /'
+            echo ""
+            echo "Expected pattern: draftlogs/<number>_(fix|add|remove|change|deprecate).md"
+            echo "See draftlogs/README.md for details."
+            exit 1
+          fi
+
+          MISSING_LINK=""
+          while IFS= read -r f; do
+            [ -z "$f" ] && continue
+            if ! grep -qE '\[\[#[0-9]+\]\(https://github\.com/plotly/plotly\.js/pull/[0-9]+\)\]' "$f"; then
+              MISSING_LINK="$MISSING_LINK$f"$'\n'
+            fi
+          done <<< "$ADDED"
+
+          if [ -n "$MISSING_LINK" ]; then
+            echo "::error::Draftlog entry(ies) missing a PR link:"
+            printf '%s' "$MISSING_LINK" | sed 's/^/  - /'
+            echo ""
+            echo "Each entry must include a link in the form:"
+            echo "  [[#1234](https://github.com/plotly/plotly.js/pull/1234)]"
+            echo "See draftlogs/README.md for an example."
+            exit 1
+          fi
+
+          echo "Found new draftlog entry(ies):"
+          echo "$ADDED" | sed 's/^/  - /'

CONTRIBUTING.md

@@ -71,6 +71,7 @@ We use the following [labels](https://github.com/plotly/plotly.js/labels) to tra
 | `status: in progress` | PRs that required some initial feedback but not ready to merge |
 | `status: reviewable` | PRs that are completed from the author's perspective |
 | `status: on hold` | PRs that are put on hold |
+| `no-draftlog` | PR opted out of the [draftlog](./draftlogs/README.md) check |
 
 ## Development
 

draftlogs/README.md

@@ -19,4 +19,15 @@ If your PR falls into more than one category - for example adding a new feature
 which would render
  - Add `icicle` trace type [[#5546](https://github.com/plotly/plotly.js/pull/5546)]
 
-> Please start your single-line or multiple lined message with a verb. You could basically use the PR description while providing a link to the PR similar to the above example is appreciated too.
+> Please start your single-line or multiple lined message with a verb.
+
+Each entry must include a link back to the PR in the form shown above:
+`[[#1234](https://github.com/plotly/plotly.js/pull/1234)]` (a link to
+`/issues/1234` is also accepted, since GitHub redirects between the two).
+
+### Skipping the draftlog
+
+A CI check enforces that every pull request adds a new file under
+`draftlogs/`. If your PR genuinely does not warrant a CHANGELOG entry
+(e.g. a CI-only change, internal refactor, or docs typo), add the
+`no-draftlog` label to the PR to opt out.