From dd08415c849e77ea41db81e3d5a9eae763c6f55a Mon Sep 17 00:00:00 2001
From: Ricki Hirner <hirner@bitfire.at>
Date: Wed, 10 Apr 2024 12:36:52 +0200
Subject: [PATCH] [CI] Improve caching behavior

---
 .github/workflows/codeql.yml   | 10 +++----
 .github/workflows/test-dev.yml | 50 +++++++++++++---------------------
 2 files changed, 24 insertions(+), 36 deletions(-)

diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index f9593017..0ac158e3 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -36,14 +36,14 @@ jobs:
     - uses: gradle/actions/setup-gradle@v3
       with:
         cache-encryption-key: ${{ secrets.gradle_encryption_key }}
+        cache-read-only: true         # gradle user home cache is generated by test jobs
 
-    - name: Use app/build and gradle configuration cache
+    - name: Use incremental build cache
       uses: actions/cache/restore@v4
       with:
-        key: app_build-tests-without-emulator
-        path: |
-          .gradle/configuration-cache
-          app/build
+        key: incremental-build-tests
+        restore-keys: incremental-build-tests   # restore cache from main branch
+        path: app/build
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
diff --git a/.github/workflows/test-dev.yml b/.github/workflows/test-dev.yml
index fdb31c46..36e7f180 100644
--- a/.github/workflows/test-dev.yml
+++ b/.github/workflows/test-dev.yml
@@ -24,29 +24,19 @@ jobs:
       - uses: gradle/actions/setup-gradle@v3
         with:
           cache-encryption-key: ${{ secrets.gradle_encryption_key }}
-          cache-write-only: ${{ env.is_main_branch }}     # otherwise build cache will grow larger and larger
+          cache-read-only: true       # gradle user home cache is generated by test_on_emulator
 
-      - name: Create app/build and gradle configuration cache
-        if: ${{ env.is_main_branch }}
-        uses: actions/cache@v4
-        with:
-          key: app_build-tests-without-emulator-${{ github.run_id }}
-          path: |
-            .gradle/configuration-cache
-            app/build
-      - name: Use app/build and gradle configuration cache
-        if: ${{ !env.is_main_branch }}
+      - name: Use incremental build cache
         uses: actions/cache/restore@v4
         with:
-          key: app_build-tests-without-emulator
-          restore-keys: app_build-tests-without-emulator-   # restore cache from main branch
-          path: |
-            .gradle/configuration-cache
-            app/build
+          key: incremental-build-tests
+          restore-keys: incremental-build-tests   # restore cache from main branch
+          path: app/build
 
       - name: Run lint and unit tests
-        run: ./gradlew --build-cache --configuration-cache --configuration-cache-problems=warn app:check
+        run: ./gradlew --build-cache --configuration-cache --configuration-cache-problems=warn --no-daemon app:check
 
+  # generates the build caches because it uses more gradle dependencies
   test_on_emulator:
     name: Tests with emulator
     runs-on: ubuntu-latest
@@ -59,22 +49,14 @@ jobs:
       - uses: gradle/actions/setup-gradle@v3
         with:
           cache-encryption-key: ${{ secrets.gradle_encryption_key }}
-          cache-write-only: ${{ env.is_main_branch }}     # otherwise build cache will grow larger and larger
-
-      - name: Create app/build and gradle configuration cache
-        if: ${{ env.is_main_branch }}
-        uses: actions/cache@v4
-        with:
-          key: app_build-tests-with-emulator-${{ github.run_id }}
-          path: |
-            .gradle/configuration-cache
-            app/build
-      - name: Use app/build and gradle configuration cache
+          gradle-home-cache-cleanup: true     # avoid ever-growing gradle user home cache
+ 
+      - name: Use incremental build cache
         if: ${{ !env.is_main_branch }}
         uses: actions/cache/restore@v4
         with:
-          key: app_build-tests-with-emulator
-          restore-keys: app_build-tests-with-emulator-   # restore cache from main branch
+          key: incremental-build-tests
+          restore-keys: incremental-build-tests       # restore cache from main branch
           path: |
             .gradle/configuration-cache
             app/build
@@ -92,5 +74,11 @@ jobs:
           key: avd-${{ hashFiles('app/build.gradle.kts') }}   # gradle-managed devices are defined there
 
       - name: Run device tests
-        run: ./gradlew --build-cache --configuration-cache --configuration-cache-problems=warn app:virtualCheck
+        run: ./gradlew --build-cache --configuration-cache --configuration-cache-problems=warn --no-daemon app:virtualCheck
 
+      - name: Create incremental build cache
+        if: ${{ env.is_main_branch }}
+        uses: actions/cache/save@v4
+        with:
+          key: incremental-build-tests-${{ github.run_id }}
+          path: app/build