Tidy-up caching code

- Extracted common code for Gradle User Home and Project .gradle caches
  into abstract supertype.
- Improve error handling by checking error types

src/cache-gradle-user-home.ts

@@ -2,86 +2,26 @@ import path from 'path'
 import fs from 'fs'
 import os from 'os'
 
-import * as core from '@actions/core'
+import {AbstractCache} from './cache-utils'
-import * as cache from '@actions/cache'
-import {generateCacheKey} from './cache-utils'
 
 const CACHE_PATH = [
     '~/.gradle/caches/*', // All directories in 'caches'
     '~/.gradle/notifications/*', // Prevent the re-rendering of first-use message for version
     '~/.gradle/wrapper/dists/*/*/*.zip' // Only wrapper zips are required : Gradle will expand these on demand
 ]
-const CACHE_KEY = 'GUH_CACHE_KEY'
-const CACHE_RESULT = 'GUH_CACHE_RESULT'
 
-export async function restore(): Promise<void> {
+export class GradleUserHomeCache extends AbstractCache {
-    if (gradleUserHomeExists()) {
+    constructor() {
-        core.info('Gradle User Home already exists. Not restoring from cache.')
+        super('gradle', 'Gradle User Home')
-        return
     }
 
-    const cacheKey = generateCacheKey('gradle')
+    protected cacheOutputExists(): boolean {
-
-    core.saveState(CACHE_KEY, cacheKey.key)
-
-    const cacheResult = await cache.restoreCache(
-        CACHE_PATH,
-        cacheKey.key,
-        cacheKey.restoreKeys
-    )
-
-    if (!cacheResult) {
-        core.info(
-            'Gradle User Home cache not found. Will start with empty home.'
-        )
-        return
-    }
-
-    core.info(`Gradle User Home restored from cache key: ${cacheResult}`)
-    return
-}
-
-export async function save(): Promise<void> {
-    if (!gradleUserHomeExists()) {
-        core.debug('No Gradle User Home to cache.')
-        return
-    }
-
-    const cacheKey = core.getState(CACHE_KEY)
-    const cacheResult = core.getState(CACHE_RESULT)
-
-    if (!cacheKey) {
-        core.info(
-            'Gradle User Home existed prior to cache restore. Not saving.'
-        )
-        return
-    }
-
-    if (cacheResult && cacheKey === cacheResult) {
-        core.info(
-            `Cache hit occurred on the cache key ${cacheKey}, not saving cache.`
-        )
-        return
-    }
-
-    core.info(`Caching Gradle User Home with cache key: ${cacheKey}`)
-    try {
-        await cache.saveCache(CACHE_PATH, cacheKey)
-    } catch (error) {
-        if (error.name === cache.ValidationError.name) {
-            throw error
-        } else if (error.name === cache.ReserveCacheError.name) {
-            core.info(error.message)
-        } else {
-            core.info(`[warning] ${error.message}`)
-        }
-    }
-
-    return
-}
-
-function gradleUserHomeExists(): boolean {
         // Need to check for 'caches' directory to avoid incorrect detection on MacOS agents
         const dir = path.resolve(os.homedir(), '.gradle/caches')
         return fs.existsSync(dir)
     }
+
+    protected getCachePath(): string[] {
+        return CACHE_PATH
+    }
+}

src/cache-project-dot-gradle.ts

@@ -1,94 +1,29 @@
 import path from 'path'
 import fs from 'fs'
-
+import {AbstractCache} from './cache-utils'
-import * as core from '@actions/core'
-import * as cache from '@actions/cache'
-import {generateCacheKey} from './cache-utils'
 
 const PATHS_TO_CACHE = [
     'configuration-cache' // Only configuration-cache is stored at present
 ]
-const CACHE_KEY = 'PROJECT_CACHE_KEY'
-const CACHE_RESULT = 'PROJECT_CACHE_RESULT'
 
-export async function restore(rootDir: string): Promise<void> {
+export class ProjectDotGradleCache extends AbstractCache {
-    if (projectDotGradleDirExists(rootDir)) {
+    private rootDir: string
-        core.info(
+    constructor(rootDir: string) {
-            'Project .gradle directory already exists. Not restoring from cache.'
+        super('project', 'Project .gradle directory')
-        )
+        this.rootDir = rootDir
-        return
     }
 
-    const cacheKey = generateCacheKey('project')
+    protected cacheOutputExists(): boolean {
-
+        const dir = this.getProjectDotGradleDir()
-    core.saveState(CACHE_KEY, cacheKey.key)
+        return fs.existsSync(dir)
-
-    const cacheResult = await cache.restoreCache(
-        getCachePath(rootDir),
-        cacheKey.key,
-        cacheKey.restoreKeys
-    )
-
-    if (!cacheResult) {
-        core.info('Project .gradle cache not found. Will start with empty.')
-        return
     }
 
-    core.info(`Project .gradle dir restored from cache key: ${cacheResult}`)
+    protected getCachePath(): string[] {
-    return
+        const dir = this.getProjectDotGradleDir()
-}
-
-export async function save(rootDir: string): Promise<void> {
-    if (!projectDotGradleDirExists(rootDir)) {
-        core.debug('No project .gradle dir to cache.')
-        return
-    }
-
-    const cacheKey = core.getState(CACHE_KEY)
-    const cacheResult = core.getState(CACHE_RESULT)
-
-    if (!cacheKey) {
-        core.info(
-            'Project .gradle dir existed prior to cache restore. Not saving.'
-        )
-        return
-    }
-
-    if (cacheResult && cacheKey === cacheResult) {
-        core.info(
-            `Cache hit occurred on the cache key ${cacheKey}, not saving cache.`
-        )
-        return
-    }
-
-    core.info(`Caching project .gradle dir with cache key: ${cacheKey}`)
-    try {
-        await cache.saveCache(getCachePath(rootDir), cacheKey)
-    } catch (error) {
-        if (error.name === cache.ValidationError.name) {
-            throw error
-        } else if (error.name === cache.ReserveCacheError.name) {
-            core.info(error.message)
-        } else {
-            core.info(`[warning] ${error.message}`)
-        }
-    }
-
-    return
-}
-
-function getCachePath(rootDir: string): string[] {
-    const dir = getProjectDotGradleDir(rootDir)
         return PATHS_TO_CACHE.map(x => path.resolve(dir, x))
     }
 
-function getProjectDotGradleDir(rootDir: string): string {
+    private getProjectDotGradleDir(): string {
-    core.debug(`Resolving .gradle dir in ${rootDir}`)
+        return path.resolve(this.rootDir, '.gradle')
-    return path.resolve(rootDir, '.gradle')
     }
-
-function projectDotGradleDirExists(rootDir: string): boolean {
-    const dir = getProjectDotGradleDir(rootDir)
-    core.debug(`Checking for existence of project .gradle dir: ${dir}`)
-    return fs.existsSync(dir)
 }

src/cache-utils.ts

@@ -1,4 +1,5 @@
 import * as core from '@actions/core'
+import * as cache from '@actions/cache'
 import * as github from '@actions/github'
 import * as crypto from 'crypto'
 
@@ -25,7 +26,7 @@ function getCacheEnabledValue(cacheName: string): string {
     )
 }
 
-export function generateCacheKey(cacheName: string): CacheKey {
+function generateCacheKey(cacheName: string): CacheKey {
     // Prefix can be used to force change all cache keys
     const cacheKeyPrefix = process.env['CACHE_KEY_PREFIX'] || ''
 
@@ -70,7 +71,7 @@ export function hashStrings(values: string[]): string {
     return hash.digest('hex')
 }
 
-export class CacheKey {
+class CacheKey {
     key: string
     restoreKeys: string[]
 
@@ -79,3 +80,95 @@ export class CacheKey {
         this.restoreKeys = restoreKeys
     }
 }
+
+export abstract class AbstractCache {
+    private cacheName: string
+    private cacheDescription: string
+    private cacheKeyStateKey: string
+    private cacheResultStateKey: string
+
+    constructor(cacheName: string, cacheDescription: string) {
+        this.cacheName = cacheName
+        this.cacheDescription = cacheDescription
+        this.cacheKeyStateKey = `CACHE_KEY_${cacheName}`
+        this.cacheResultStateKey = `CACHE_RESULT_${cacheName}`
+    }
+
+    async restore(): Promise<void> {
+        if (this.cacheOutputExists()) {
+            core.info(
+                `${this.cacheDescription} already exists. Not restoring from cache.`
+            )
+            return
+        }
+
+        const cacheKey = generateCacheKey(this.cacheName)
+
+        core.saveState(this.cacheKeyStateKey, cacheKey.key)
+
+        const cacheResult = await cache.restoreCache(
+            this.getCachePath(),
+            cacheKey.key,
+            cacheKey.restoreKeys
+        )
+
+        if (!cacheResult) {
+            core.info(
+                `${this.cacheDescription} cache not found. Will start with empty.`
+            )
+            return
+        }
+
+        core.saveState(this.cacheResultStateKey, cacheResult)
+
+        core.info(
+            `${this.cacheDescription} restored from cache key: ${cacheResult}`
+        )
+        return
+    }
+
+    async save(): Promise<void> {
+        if (!this.cacheOutputExists()) {
+            core.debug(`No ${this.cacheDescription} to cache.`)
+            return
+        }
+
+        const cacheKey = core.getState(this.cacheKeyStateKey)
+        const cacheResult = core.getState(this.cacheResultStateKey)
+
+        if (!cacheKey) {
+            core.info(
+                `${this.cacheDescription} existed prior to cache restore. Not saving.`
+            )
+            return
+        }
+
+        if (cacheResult && cacheKey === cacheResult) {
+            core.info(
+                `Cache hit occurred on the cache key ${cacheKey}, not saving cache.`
+            )
+            return
+        }
+
+        core.info(
+            `Caching ${this.cacheDescription} with cache key: ${cacheKey}`
+        )
+        try {
+            await cache.saveCache(this.getCachePath(), cacheKey)
+        } catch (error) {
+            // Fail on validation errors or non-errors (the latter to keep Typescript happy)
+            if (
+                error instanceof cache.ValidationError ||
+                !(error instanceof Error)
+            ) {
+                throw error
+            }
+            core.warning(error.message)
+        }
+
+        return
+    }
+
+    protected abstract cacheOutputExists(): boolean
+    protected abstract getCachePath(): string[]
+}

src/caches.ts

@@ -1,5 +1,5 @@
-import * as cacheGradleUserHome from './cache-gradle-user-home'
+import {GradleUserHomeCache} from './cache-gradle-user-home'
-import * as cacheProjectDotGradle from './cache-project-dot-gradle'
+import {ProjectDotGradleCache} from './cache-project-dot-gradle'
 import * as core from '@actions/core'
 import {isCacheReadEnabled, isCacheSaveEnabled} from './cache-utils'
 
@@ -12,9 +12,9 @@ export async function restore(buildRootDirectory: string): Promise<void> {
     }
 
     core.startGroup('Restore Gradle state from cache')
-    await cacheGradleUserHome.restore()
     core.saveState(BUILD_ROOT_DIR, buildRootDirectory)
-    await cacheProjectDotGradle.restore(buildRootDirectory)
+    new GradleUserHomeCache().restore()
+    new ProjectDotGradleCache(buildRootDirectory).restore()
     core.endGroup()
 }
 
@@ -25,8 +25,8 @@ export async function save(): Promise<void> {
     }
 
     core.startGroup('Caching Gradle state')
-    await cacheGradleUserHome.save()
     const buildRootDirectory = core.getState(BUILD_ROOT_DIR)
-    await cacheProjectDotGradle.save(buildRootDirectory)
+    new GradleUserHomeCache().save()
+    new ProjectDotGradleCache(buildRootDirectory).save()
     core.endGroup()
 }

src/main.ts

@@ -36,6 +36,9 @@ export async function run(): Promise<void> {
             core.setFailed(`Gradle process exited with status ${result.status}`)
         }
     } catch (error) {
+        if (!(error instanceof Error)) {
+            throw error
+        }
         core.setFailed(error.message)
     }
 }

src/provision.ts

@@ -142,13 +142,14 @@ async function downloadAndCacheGradleDistribution(
         try {
             await cache.saveCache([downloadPath], cacheKey)
         } catch (error) {
-            if (error.name === cache.ValidationError.name) {
+            // Fail on validation errors or non-errors (the latter to keep Typescript happy)
+            if (
+                error instanceof cache.ValidationError ||
+                !(error instanceof Error)
+            ) {
                 throw error
-            } else if (error.name === cache.ReserveCacheError.name) {
-                core.info(error.message)
-            } else {
-                core.info(`[warning] ${error.message}`)
             }
+            core.warning(error.message)
         }
     }
     return downloadPath