CI: Add a workflow which automates some labeling (#2812)

* Initial content-based labeling

* Improve labeling rules around docs and /worlds/generic

* Improve labeling rules around docs and webhost

* Formatting

* Update matching for webhost

* back to square 1 on is:docu

* Try a better glob for docs

* Formatting

* Manage PR state labels

* Correct syntax for conditions

* Correct syntax for conditions

* add trigger on reopening

* add trigger on closing

* keep labels in sync as pr updates

* Change edit event to sync

* Restrict only to PRs to main

* address review comments

* apply only to PRs into main

.github/labeler.yml

@@ -0,0 +1,30 @@
+'is: documentation':
+- changed-files:
+  - all-globs-to-all-files: '{**/docs/**,**/README.md}'
+
+'affects: webhost':
+- changed-files:
+  - all-globs-to-any-file: 'WebHost.py'
+  - all-globs-to-any-file: 'WebHostLib/**/*'
+
+'affects: core':
+- changed-files:
+  - all-globs-to-any-file:
+    - '!*Client.py'
+    - '!README.md'
+    - '!LICENSE'
+    - '!*.yml'
+    - '!.gitignore'
+    - '!**/docs/**'
+    - '!typings/kivy/**'
+    - '!test/**'
+    - '!data/**'
+    - '!.run/**'
+    - '!.github/**'
+    - '!worlds_disabled/**'
+    - '!worlds/**'
+    - '!WebHost.py'
+    - '!WebHostLib/**'
+  - any-glob-to-any-file: # exceptions to the above rules of "stuff that isn't core"
+    - 'worlds/generic/**/*.py'
+    - 'CommonClient.py'

.github/workflows/label-pull-requests.yml

@@ -0,0 +1,44 @@
+name: Label Pull Request
+on:
+  pull_request_target:
+    types: ['opened', 'reopened', 'synchronize', 'ready_for_review', 'converted_to_draft', 'closed']
+    branches: ['main']
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  labeler:
+    name: 'Apply content-based labels'
+    if: github.event.action == 'opened' || github.event.action == 'reopened' || github.event.action == 'synchronize'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/labeler@v5
+        with:
+          sync-labels: true
+  peer_review:
+    name: 'Apply peer review label'
+    if: >-
+      (github.event.action == 'opened' || github.event.action == 'reopened' || 
+      github.event.action == 'ready_for_review') && !github.event.pull_request.draft
+    runs-on: ubuntu-latest
+    steps:
+      - name: 'Add label'
+        run: "gh pr edit \"$PR_URL\" --add-label 'waiting-on: peer-review'"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  unblock_draft_prs:
+    name: 'Remove waiting-on labels'
+    if: github.event.action == 'converted_to_draft' || github.event.action == 'closed'
+    runs-on: ubuntu-latest
+    steps:
+      - name: 'Remove labels'
+        run: |-
+          gh pr edit "$PR_URL" --remove-label 'waiting-on: peer-review' \
+            --remove-label 'waiting-on: core-review' \
+            --remove-label 'waiting-on: world-maintainer' \
+            --remove-label 'waiting-on: author'
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}