Merge 3b3fb41561 into 5656298164

.github/workflows/codeql.yml

@@ -20,7 +20,7 @@ jobs:
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v4
+      uses: github/codeql-action/init@v3
       # Override language selection by uncommenting this and choosing your languages
       # with:
       #   languages: go, javascript, csharp, python, cpp, java, ruby
@@ -28,7 +28,7 @@ jobs:
     # Autobuild attempts to build any compiled languages (C/C++, C#, Go, or Java).
     # If this step fails, then you should remove it and run the build manually (see below).
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v4
+      uses: github/codeql-action/autobuild@v3
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
@@ -42,4 +42,4 @@ jobs:
     #     make release
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v4
+      uses: github/codeql-action/analyze@v3

caching-strategies.md

@@ -287,3 +287,26 @@ steps:
   - name: Publish package to public
     run: ./publish.sh
 ```
+
+### Saving cache only if the build runs on the default branch
+
+Workflow runs can restore caches created in either the current branch or the default branch (usually `main`) [Reference](https://docs.github.com/en/actions/reference/workflows-and-actions/dependency-caching#restrictions-for-accessing-a-cache).
+
+By restricting caches to the default branch, we can reduce the risk that Github evicts a cache created on the default branch. If that happens, every PR will create its own cache, increasing the cache churn.
+
+We can condition the execution of the `actions/cache/save` action on the current branch:
+
+```yaml
+steps:
+  - uses: actions/checkout@v3
+  .
+  . // restore if need be
+  .
+  - name: Build
+    run: /build.sh
+  - uses: actions/cache/save@v3
+    if: ${{ github.ref == 'refs/heads/main' }} // check we are on the default branch
+    with:
+      path: path/to/dependencies
+      key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
+```