Compute wrapper cache key

__tests__/cache.test.ts

@@ -0,0 +1,33 @@
+import * as cache from '../src/cache'
+import * as path from 'path'
+
+describe('cache', () => {
+    describe('can extract gradle wrapper slug', () => {
+        it('from wrapper properties file', async () => {
+            const version = cache.extractGradleWrapperSlugFrom(
+                path.resolve(
+                    '__tests__/data/basic/gradle/wrapper/gradle-wrapper.properties'
+                )
+            )
+            expect(version).toBe('6.5-bin')
+        })
+        it('for -bin dist', async () => {
+            const version = cache.extractGradleWrapperSlugFromDistUri(
+                'distributionUrl=https\\://services.gradle.org/distributions/gradle-6.5-bin.zip'
+            )
+            expect(version).toBe('6.5-bin')
+        })
+        it('for -all dist', async () => {
+            const version = cache.extractGradleWrapperSlugFromDistUri(
+                'distributionUrl=https\\://services.gradle.org/distributions/gradle-6.5-all.zip'
+            )
+            expect(version).toBe('6.5-all')
+        })
+        it('for milestone', async () => {
+            const version = cache.extractGradleWrapperSlugFromDistUri(
+                'distributionUrl=https\\://services.gradle.org/distributions/gradle-6.6-milestone-1-all.zip'
+            )
+            expect(version).toBe('6.6-milestone-1-all')
+        })
+    })
+})

__tests__/main.test.ts

@@ -1,3 +0,0 @@
-describe('TODO - Add a test suite', () => {
-    it('TODO - Add a test', async () => {})
-})

src/cache.ts

@@ -1,18 +1,52 @@
 import * as core from '@actions/core'
 import * as path from 'path'
+import * as fs from 'fs'
+
+const WRAPPER_CACHE_KEY = 'WRAPPER_CACHE_KEY'
+const WRAPPER_CACHE_PATH = 'WRAPPER_CACHE_PATH'
 
 export async function restoreCachedWrapperDist(
     executableDirectory: string
 ): Promise<void> {
-    core.saveState('WRAPPER_BASE_DIR', path.resolve(executableDirectory))
-    core.info(`WRAPPER_BASE_DIR = ${core.getState('WRAPPER_BASE_DIR')}`)
-    const wrapperProperties = path.join(
-        executableDirectory,
-        'gradle/wrapper/gradle-wrapper.properties'
+    const wrapperSlug = extractGradleWrapperSlugFrom(
+        path.join(
+            path.resolve(executableDirectory),
+            'gradle/wrapper/gradle-wrapper.properties'
+        )
     )
-    core.info(`wrapper properties = ${wrapperProperties}`)
+    const wrapperCacheKey = `wrapper-${wrapperSlug}`
+    const wrapperCachePath = path.join(
+        process.env.HOME!,
+        `.gradle/wrapper/dists/gradle-${wrapperSlug}`
+    )
+    core.info(`${WRAPPER_CACHE_KEY} = ${wrapperCacheKey}`)
+    core.info(`${WRAPPER_CACHE_PATH} = ${wrapperCachePath}`)
+    core.saveState(WRAPPER_CACHE_KEY, wrapperCacheKey)
+    core.saveState(WRAPPER_CACHE_PATH, wrapperCachePath)
+    return
 }
 
 export async function cacheWrapperDist(): Promise<void> {
-    core.info(`WRAPPER_BASE_DIR = ${core.getState('WRAPPER_BASE_DIR')}`)
+    core.info(`${WRAPPER_CACHE_KEY} = ${core.getState(WRAPPER_CACHE_KEY)}`)
+    core.info(`${WRAPPER_CACHE_PATH} = ${core.getState(WRAPPER_CACHE_PATH)}`)
+    return
+}
+
+export function extractGradleWrapperSlugFrom(
+    wrapperProperties: string
+): string | null {
+    const props = fs.readFileSync(wrapperProperties, {encoding: 'utf8'})
+    const distUrlLine = props
+        .split('\n')
+        .find(line => line.startsWith('distributionUrl'))
+    if (!distUrlLine) return null
+    return extractGradleWrapperSlugFromDistUri(distUrlLine.substr(16).trim())
+}
+
+export function extractGradleWrapperSlugFromDistUri(
+    distUri: string
+): string | null {
+    const regex = /.*gradle-(.*-(bin|all))\.zip/
+    const match = distUri.match(regex)
+    return match ? match[1] : null
 }