Attempt to use gradle wrapper for cache cleanup (#525)

The cache-cleanup operation works by executing Gradle on a dummy project
and a custom init-script. The version of Gradle used should be at least
as high as the newest version used to run a build.

Previously, if the Gradle version on PATH didn't meet this requirement,
the action would download and install the required Gradle version.

With this PR, the action will now use an existing Gradle wrapper
distribution if it meets the requirement. This avoids unnecessary
downloads of Gradle versions that are already present on the runner.

The logic is:
- Determine the newest version of Gradle that was executed during the
Job. This is the 'minimum version' for cache cleanup.
- Inspect the Gradle version on PATH and any detected wrapper scripts to
see if they meet the 'minimum version'.
- The first executable that is found to meet the requirements will be
used for cache-cleanup.
- If no executable is found that meets the requirements, attempt to
provision Gradle with the 'minimum version'.

Fixes #515

sources/src/caching/cache-cleaner.ts

@@ -4,8 +4,9 @@ import * as exec from '@actions/exec'
 import fs from 'fs'
 import path from 'path'
 import * as provisioner from '../execution/provision'
-import {BuildResults} from '../build-results'
+import {BuildResult, BuildResults} from '../build-results'
 import {versionIsAtLeast} from '../execution/gradle'
+import {gradleWrapperScript} from '../execution/gradlew'
 
 export class CacheCleaner {
     private readonly gradleUserHome: string
@@ -38,7 +39,11 @@ export class CacheCleaner {
         const preferredVersion = buildResults.highestGradleVersion()
         if (preferredVersion && versionIsAtLeast(preferredVersion, '8.11')) {
             try {
-                return await provisioner.provisionGradleAtLeast(preferredVersion)
+                const wrapperScripts = buildResults.results
+                    .map(result => this.findGradleWrapperScript(result))
+                    .filter(Boolean) as string[]
+
+                return await provisioner.provisionGradleWithVersionAtLeast(preferredVersion, wrapperScripts)
             } catch (e) {
                 // Ignore the case where the preferred version cannot be located in https://services.gradle.org/versions/all.
                 // This can happen for snapshot Gradle versions.
@@ -49,7 +54,17 @@ export class CacheCleaner {
         }
 
         // Fallback to the minimum version required for cache-cleanup
-        return await provisioner.provisionGradleAtLeast('8.11')
+        return await provisioner.provisionGradleWithVersionAtLeast('8.11')
+    }
+
+    private findGradleWrapperScript(result: BuildResult): string | null {
+        try {
+            const wrapperScript = gradleWrapperScript(result.rootProjectDir)
+            return path.resolve(result.rootProjectDir, wrapperScript)
+        } catch (error) {
+            core.debug(`No Gradle Wrapper found for ${result.rootProjectName}: ${error}`)
+            return null
+        }
     }
 
     // Visible for testing