Reuse cached content in "build", "bcr_test_module", "test-indexers" jobs

.github/actions/bazel-cache/action.yaml

@@ -0,0 +1,63 @@
+name: Checkout Bazel server and disk caches
+inputs:
+  bazel-version:
+    description: Used custom bazel version (or .bazelversion if empty)
+    required: false
+  bazelrc:
+    description: Used custom rc file (or .bazelrc if empty)
+    required: false
+  disk-cache-max-size:
+    description: Max size for disk cache GC (e.g. 5G)
+    required: false
+    default: '5G'
+outputs:
+  disk-cache-flags:
+    description: Bazel flags for disk cache (use in bazel build/test)
+    value: ${{ steps.set-flags.outputs.disk-cache-flags }}
+runs:
+  using: 'composite'
+  steps:
+    - name: Bazel server cache
+      uses: actions/cache@v5
+      env:
+        BAZEL_VERSION: ${{ inputs.bazel-version || '.bazelversion' }}
+        BAZELRC: ${{ inputs.bazelrc || '.bazelrc' }}
+      with:
+        path: ${{ runner.os == 'Linux' && '/home/runner/.cache/bazel' || '/Users/runner/Library/Caches/Bazel' }}
+        # Richer hash than disk cache: server cache has no history, so it
+        # changes often; separate blobs avoid overwriting caches for different
+        # dep graphs.
+        key: >-
+          ${{format(
+            'bazel-{0}-{1}-{2}-{3}',
+            runner.os,
+            env.BAZEL_VERSION,
+            env.BAZELRC,
+            hashFiles('**/BUILD', '**/BUILD.bazel', '**/*.bzl', 'MODULE.bazel', '.bazelversion', '.bazelrc*')
+          )}}
+        restore-keys: |
+          ${{format(
+            'bazel-{0}-{1}-{2}-',
+            runner.os,
+            env.BAZEL_VERSION,
+            env.BAZELRC
+          )}}
+    - name: Bazel disk cache
+      uses: actions/cache@v5
+      env:
+        BAZEL_VERSION: ${{ inputs.bazel-version || '.bazelversion' }}
+        BAZELRC: ${{ inputs.bazelrc || '.bazelrc' }}
+      with:
+        path: ${{ runner.os == 'Linux' && '/home/runner/.bazel-disk-cache' || '/Users/runner/.bazel-disk-cache' }}
+        key: >-
+          ${{format(
+            'bazel-disk-{0}-{1}-{2}',
+            runner.os,
+            env.BAZEL_VERSION,
+            env.BAZELRC
+          )}}
+    - name: Set disk cache flags output
+      id: set-flags
+      run: |
+        echo "disk-cache-flags=--disk_cache=$HOME/.bazel-disk-cache --experimental_disk_cache_gc_max_size=${{ inputs.disk-cache-max-size }}" >> "$GITHUB_OUTPUT"
+      shell: bash

.github/workflows/ci.yaml

@@ -30,16 +30,21 @@ jobs:
       USE_BAZEL_VERSION: ${{ matrix.bazel-version }}
       BAZELRC: ${{ matrix.custom-bazelrc }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
+      - uses: ./.github/actions/bazel-cache
+        id: bazel-cache
+        with:
+          bazel-version: ${{ matrix.bazel-version }}
+          bazelrc: ${{ matrix.custom-bazelrc }}
       - name: Build
         run: |
-          bazel build //...
+          bazel build ${{ steps.bazel-cache.outputs.disk-cache-flags }} //...
       - name: Test
         run: |
-          bazel test --test_output=errors //...
+          bazel test --test_output=errors ${{ steps.bazel-cache.outputs.disk-cache-flags }} //...
 
   # Imitate the BCR test in .bcr/presubmit.yml. Keep in sync.
-  bcr_test_module:
+  bcr-test-module:
     strategy:
       matrix:
         os: [ubuntu-24.04, macos-26]
@@ -52,37 +57,43 @@ jobs:
       run:
         working-directory: "example/bzlmod"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
+      - uses: ./.github/actions/bazel-cache
+        id: bazel-cache
+        with:
+          bazel-version: ${{ matrix.bazel-version || '.bazelversion' }}
       - name: Run Gazelle
-        run: "bazel run //:gazelle"
+        run: "bazel run ${{ steps.bazel-cache.outputs.disk-cache-flags }} //:gazelle"
       - name: Build
-        run: "bazel build //..."
+        run: "bazel build ${{ steps.bazel-cache.outputs.disk-cache-flags }} //..."
       - name: Test
-        run: "bazel test //..."
+        run: "bazel test ${{ steps.bazel-cache.outputs.disk-cache-flags }} //..."
 
   test-indexers:
     runs-on: ubuntu-24.04
     timeout-minutes: 15
     steps:
-    - uses: actions/checkout@v4
-    - name: Install Conan
-      run: |
-        python3 -m pip install --upgrade pip
-        pip install conan
-    - name: Execute manual integration tests
-      run: bazel test --test_output=errors //index:integration_tests
+      - uses: actions/checkout@v6
+      - uses: ./.github/actions/bazel-cache
+        id: bazel-cache
+      - name: Install Conan
+        run: |
+          python3 -m pip install --upgrade pip
+          pip install conan
+      - name: Execute manual integration tests
+        run: bazel test --test_output=errors ${{ steps.bazel-cache.outputs.disk-cache-flags }} //index:integration_tests
 
   test-e2e:
     runs-on: ubuntu-24.04
     timeout-minutes: 15
     steps:
-    - uses: actions/checkout@v4  
-    - name: Execute end to end tests
-      run: bash .github/workflows/test_e2e.sh
+      - uses: actions/checkout@v6
+      - name: Execute end to end tests
+        run: bash .github/workflows/test_e2e.sh
 
   license-headers:
     runs-on: ubuntu-24.04
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v4
-      - run: ./scripts/license_check.sh 
+      - uses: actions/checkout@v6
+      - run: ./scripts/license_check.sh

.github/workflows/generate_bzldep_index.yaml

@@ -13,14 +13,14 @@ jobs:
   build-plan:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: coursier/cache-action@v6     
       - uses: coursier/setup-action@v1
         with:
           apps: scala
 
       # Reuse already resolved info if available
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: .cache/
           key: gen-mappings-indexer-cache

.gitignore

@@ -1,6 +1,8 @@
 # Build / tooling
-bazel-*
-sandbox/*
+/bazel-*
+/example/bzlmod/bazel-*
+/example/workspace/bazel-*
+/sandbox/*
 .cache
 .scala-build
 .metals