review: group dependabot updates and automerge patches

.github/dependabot.yaml

@@ -1,4 +1,4 @@
-# https://docs.github.com/en/code-security/dependabot/working-with-dependabot/dependabot-options-reference#package-ecosystem-
+# https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/optimizing-pr-creation-version-updates#setting-up-a-cooldown-period-for-dependency-updates
 
 version: 2
 updates:
@@ -8,11 +8,42 @@ updates:
       - tests/wasm-workspace
     schedule:
       interval: weekly
+    # https://docs.github.com/en/code-security/dependabot/working-with-dependabot/dependabot-options-reference#groups--
+    # 1 PR per week and group
+    groups:
+      major:
+        update-types: ["major"]
+      minor:
+        update-types: ["minor"]
+      patch:
+        update-types: ["patch"]
   - package-ecosystem: github-actions
     directory: /
     schedule:
       interval: weekly
+    groups:
+      actions:
+        # Combine all images of the last week
+        patterns: ["*"]
   - package-ecosystem: npm
     directory: /
     schedule:
       interval: weekly
+      prd-major:
+        dependency-type: "production"
+        update-types: ["major"]
+      prd-minor:
+        dependency-type: "production"
+        update-types: ["minor"]
+      prd-patch:
+        dependency-type: "production"
+        update-types: ["patch"]
+      dev-major:
+        dependency-type: "development"
+        update-types: ["major"]
+      dev-minor:
+        dependency-type: "development"
+        update-types: ["minor"]
+      dev-patch:
+        dependency-type: "development"
+        update-types: ["patch"]

.github/workflows/dependabot.yml

@@ -0,0 +1,25 @@
+# https://docs.github.com/en/code-security/dependabot/working-with-dependabot/automating-dependabot-with-github-actions#enabling-automerge-on-a-pull-request
+
+name: Dependabot Automation
+on: pull_request
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.user.login == 'dependabot[bot]' && github.repository == 'Swatinem/rust-cache'
+    steps:
+      - name: Fetch metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v2
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+      - name: Auto-merge Patch PRs
+        if: steps.metadata.outputs.update-type == 'version-update:semver-patch'
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}