Allow better control over cache-cleanup

Adds new 'cache-cleanup' parameter with 3 settings: 'never', 'on-success' and 'always'.
This gives users more control over whether cache cleanup should occur.

Fixes #71

sources/src/caching/cache-reporting.ts

@@ -10,9 +10,14 @@ export const DEFAULT_WRITEONLY_REASON = `[Cache was set to write-only](https://g
 
 export const EXISTING_GRADLE_HOME = `[Cache was disabled to avoid overwriting a pre-existing Gradle User Home](https://github.com/gradle/actions/blob/v3/docs/setup-gradle.md#overwriting-an-existing-gradle-user-home). Gradle User Home was not restored from or saved to the cache.`
 
-export const DEFAULT_CLEANUP_DISABLED_REASON = `[Cache cleanup](https://github.com/gradle/actions/blob/v3/docs/setup-gradle.md#remove-unused-files-from-gradle-user-home-before-saving-to-the-cache) was not enabled. It must be explicitly enabled.`
+export const CLEANUP_DISABLED_READONLY = `[Cache cleanup](https://github.com/gradle/actions/blob/v3/docs/setup-gradle.md#enabling-cache-cleanup) is always disabled when cache is read-only or disabled.`
 
-export const DEFAULT_CLEANUP_ENABLED_REASON = `[Cache cleanup](https://github.com/gradle/actions/blob/v3/docs/setup-gradle.md#remove-unused-files-from-gradle-user-home-before-saving-to-the-cache) was enabled.`
+export const DEFAULT_CLEANUP_DISABLED_REASON = `[Cache cleanup](https://github.com/gradle/actions/blob/v3/docs/setup-gradle.md#enabling-cache-cleanup) was not enabled. It must be explicitly enabled.`
+
+export const DEFAULT_CLEANUP_ENABLED_REASON = `[Cache cleanup](https://github.com/gradle/actions/blob/v3/docs/setup-gradle.md#enabling-cache-cleanup) was enabled.`
+
+export const CLEANUP_DISABLED_DUE_TO_FAILURE =
+    '[Cache cleanup was disabled due to build failure](https://github.com/gradle/actions/blob/v3/docs/setup-gradle.md#enabling-cache-cleanup). Use `cache-cleanup: always` to override this behavior.'
 
 /**
  * Collects information on what entries were saved and restored during the action.
@@ -41,11 +46,13 @@ export class CacheListener {
     setReadOnly(reason: string = DEFAULT_READONLY_REASON): void {
         this.cacheReadOnly = true
         this.cacheStatusReason = reason
+        this.cacheCleanupMessage = CLEANUP_DISABLED_READONLY
     }
 
     setDisabled(reason: string = DEFAULT_DISABLED_REASON): void {
         this.cacheDisabled = true
         this.cacheStatusReason = reason
+        this.cacheCleanupMessage = CLEANUP_DISABLED_READONLY
     }
 
     setWriteOnly(reason: string = DEFAULT_WRITEONLY_REASON): void {
@@ -57,6 +64,10 @@ export class CacheListener {
         this.cacheCleanupMessage = DEFAULT_CLEANUP_ENABLED_REASON
     }
 
+    setCacheCleanupDisabled(reason: string = DEFAULT_CLEANUP_DISABLED_REASON): void {
+        this.cacheCleanupMessage = reason
+    }
+
     entry(name: string): CacheEntryListener {
         for (const entry of this.cacheEntries) {
             if (entry.entryName === name) {

sources/src/caching/caches.ts

@@ -1,9 +1,10 @@
 import * as core from '@actions/core'
-import {CacheListener, EXISTING_GRADLE_HOME} from './cache-reporting'
+import {CacheListener, EXISTING_GRADLE_HOME, CLEANUP_DISABLED_DUE_TO_FAILURE} from './cache-reporting'
 import {GradleUserHomeCache} from './gradle-user-home-cache'
 import {CacheCleaner} from './cache-cleaner'
 import {DaemonController} from '../daemon-controller'
 import {CacheConfig} from '../configuration'
+import {BuildResults} from '../build-results'
 
 const CACHE_RESTORED_VAR = 'GRADLE_BUILD_ACTION_CACHE_RESTORED'
 
@@ -67,6 +68,7 @@ export async function save(
     gradleUserHome: string,
     cacheListener: CacheListener,
     daemonController: DaemonController,
+    buildResults: BuildResults,
     cacheConfig: CacheConfig
 ): Promise<void> {
     if (cacheConfig.isCacheDisabled()) {
@@ -88,13 +90,12 @@ export async function save(
     await daemonController.stopAllDaemons()
 
     if (cacheConfig.isCacheCleanupEnabled()) {
-        cacheListener.setCacheCleanupEnabled()
-        core.info('Forcing cache cleanup.')
-        const cacheCleaner = new CacheCleaner(gradleUserHome, process.env['RUNNER_TEMP']!)
-        try {
-            await cacheCleaner.forceCleanup()
-        } catch (e) {
-            core.warning(`Cache cleanup failed. Will continue. ${String(e)}`)
+        if (cacheConfig.shouldPerformCacheCleanup(buildResults.anyFailed())) {
+            cacheListener.setCacheCleanupEnabled()
+            await performCacheCleanup(gradleUserHome)
+        } else {
+            core.info('Not performing cache-cleanup due to build failure')
+            cacheListener.setCacheCleanupDisabled(CLEANUP_DISABLED_DUE_TO_FAILURE)
         }
     }
 
@@ -102,3 +103,13 @@ export async function save(
         return new GradleUserHomeCache(userHome, gradleUserHome, cacheConfig).save(cacheListener)
     })
 }
+
+async function performCacheCleanup(gradleUserHome: string): Promise<void> {
+    core.info('Forcing cache cleanup.')
+    const cacheCleaner = new CacheCleaner(gradleUserHome, process.env['RUNNER_TEMP']!)
+    try {
+        await cacheCleaner.forceCleanup()
+    } catch (e) {
+        core.warning(`Cache cleanup failed. Will continue. ${String(e)}`)
+    }
+}