Always set the GRADLE_USER_HOME env var

.github/workflows/integ-test-cache-cleanup.yml

@@ -79,20 +79,20 @@ jobs:
         cache-read-only: true
     - name: Report Gradle User Home
       run: |
-        du -hc ~/.gradle/caches/modules-2
-        du -hc ~/.gradle/wrapper/dists
+        du -hc $GRADLE_USER_HOME/caches/modules-2
+        du -hc $GRADLE_USER_HOME/wrapper/dists
     - name: Verify cleaned cache
       shell: bash
       run: |
-        if [ ! -e ~/.gradle/caches/modules-2/files-2.1/org.apache.commons/commons-math3/3.1.1 ]; then
+        if [ ! -e $GRADLE_USER_HOME/caches/modules-2/files-2.1/org.apache.commons/commons-math3/3.1.1 ]; then
           echo "::error ::Should find commons-math3 3.1.1 in cache"
           exit 1
         fi
-        if [ -e ~/.gradle/caches/modules-2/files-2.1/org.apache.commons/commons-math3/3.1 ]; then
+        if [ -e $GRADLE_USER_HOME/caches/modules-2/files-2.1/org.apache.commons/commons-math3/3.1 ]; then
           echo "::error ::Should NOT find commons-math3 3.1 in cache"
           exit 1
         fi
-        if [ ! -e ~/.gradle/wrapper/dists/gradle-8.0.2-bin ]; then
+        if [ ! -e $GRADLE_USER_HOME/wrapper/dists/gradle-8.0.2-bin ]; then
           echo "::error ::Should find gradle-8.0.2 in wrapper/dists"
           exit 1
         fi

docs/setup-gradle.md

@@ -172,7 +172,7 @@ cache-cleanup: 'on-success' # Valid values are 'never' (default), 'on-success' a
 
 ### Overwriting an existing Gradle User Home
 
-When the action detects that the Gradle User Home caches directory already exists (`~/.gradle/caches`), then by default it will not overwrite the existing content of this directory.
+When the action detects that the Gradle User Home caches directory already exists (`$GRADLE_USER_HOME/caches`), then by default it will not overwrite the existing content of this directory.
 This can occur when a prior action initializes this directory, or when using a self-hosted runner that retains this directory between uses.
 
 In this case, the Job Summary will display a message like:

sources/src/setup-gradle.ts

@@ -84,6 +84,7 @@ async function determineGradleUserHome(): Promise<string> {
     // Use the default Gradle User Home if it already exists
     if (fs.existsSync(defaultGradleUserHome)) {
         core.info(`Gradle User Home already exists at ${defaultGradleUserHome}`)
+        core.exportVariable('GRADLE_USER_HOME', defaultGradleUserHome)
         return defaultGradleUserHome
     }
 
@@ -95,6 +96,7 @@ async function determineGradleUserHome(): Promise<string> {
         return fasterGradleUserHome
     }
 
+    core.exportVariable('GRADLE_USER_HOME', defaultGradleUserHome)
     return defaultGradleUserHome
 }