From fad47eb92c956fc2db10a0adde966554eee8736d Mon Sep 17 00:00:00 2001
From: Jesper Terkelsen <jete@monta.com>
Date: Fri, 5 Jun 2026 09:00:34 +0200
Subject: [PATCH] ci(sonar-cloud): publish Linux-gradle-main- cache to warm PR
 fresh-branch builds [NO-JIRA]

GitHub/runs-on caches are branch-scoped: a run can only restore caches from its
own ref + the default branch (main). The Kotlin PR test workflow (#298) never
runs on main, so no Linux-gradle-* cache exists there, and its Linux-gradle-
fallback can't reach sibling PR caches -> every fresh branch's first build is
cold (~3-4m recompile).

sonar-cloud.yml already compiles + tests on main (code-analysis on push:main).
Have it save ~/.gradle under Linux-gradle-main-<sha> (split restore/save,
replacing setup-java's frozen cache:'gradle'). That sits on refs/heads/main =
default branch, so the PR test workflow's existing Linux-gradle- fallback matches
it -> fresh PR branches start warm. No change to pull-request-kotlin.yml needed.

Save is guarded to refs/heads/main so a PR-context run can't poison the baseline.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 .github/workflows/sonar-cloud.yml | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/sonar-cloud.yml b/.github/workflows/sonar-cloud.yml
index 41df8f6..98498f9 100644
--- a/.github/workflows/sonar-cloud.yml
+++ b/.github/workflows/sonar-cloud.yml
@@ -63,7 +63,16 @@ jobs:
         with:
           distribution: corretto
           java-version: ${{ inputs.java-version }}
-          cache: 'gradle'
+      - name: Restore Gradle cache
+        id: gradle-cache
+        uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-main-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-main-
       - name: Cache SonarCloud packages
         uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5
         with:
@@ -90,3 +99,11 @@ jobs:
             **/build/reports/problems/**
           if-no-files-found: ignore
           retention-days: 30
+      - name: Save Gradle cache
+        if: ${{ always() && github.ref == 'refs/heads/main' && steps.gradle-cache.outputs.cache-hit != 'true' }}
+        uses: actions/cache/save@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-main-${{ github.sha }}