Backport #1097/#1098: cache Maven and Gradle wrapper distributions separately (#1122)

Backports the wrapper caching fix to the v5 release line.

The Maven wrapper distribution (~/.m2/wrapper/dists) and Gradle wrapper
distribution (~/.gradle/wrapper) were cached in the same entry as the
dependency cache, keyed on the volatile dependency-file hashes (**/pom.xml,
**/*.gradle*). With no restoreKeys fallback (#269), almost every dependency
change was a full cache miss, forcing ./mvnw and ./gradlew to re-download the
build tool distribution and hitting intermittent rate-limit failures.

Each wrapper distribution now lives in its own additional cache entry keyed
only on the rarely-changing wrapper properties file
(**/.mvn/wrapper/maven-wrapper.properties, **/gradle-wrapper.properties), so
it survives dependency changes. Optional-cache saves swallow ValidationError
and ReserveCacheError so a project without a wrapper never fails the post step.

Fixes: #1095


Copilot-Session: ea015caa-980a-4e0a-af20-3fc9f39c77fd

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: brunoborges

README.md

@@ -149,7 +149,7 @@ The workflow output `cache-primary-key` exposes the primary cache key computed b
 
 The cache input is optional, and caching is turned off by default.
 
-**Maven Wrapper:** when `cache: 'maven'` is enabled, the action also caches and restores the Maven Wrapper distribution downloaded to `~/.m2/wrapper/dists` (in addition to the local repository), so wrapper-based (`./mvnw`) builds don't re-download the wrapper on every run. This is keyed on `**/.mvn/wrapper/maven-wrapper.properties` as shown above.
+**Maven Wrapper:** when `cache: 'maven'` is enabled, the action also caches and restores the Maven Wrapper distribution downloaded to `~/.m2/wrapper/dists` (in addition to the local repository), so wrapper-based (`./mvnw`) builds don't re-download the Maven distribution. The wrapper distribution is stored in a **separate** cache entry keyed only on `**/.mvn/wrapper/maven-wrapper.properties`, so it stays cached across the frequent `pom.xml` changes that rotate the main dependency cache key.
 
 #### Caching gradle dependencies
 ```yaml
@@ -167,6 +167,8 @@ steps:
 ```
 Using the `cache: gradle` provides a simple and effective way to cache Gradle dependencies with minimal configuration.
 
+**Gradle Wrapper:** when `cache: 'gradle'` is enabled, the action also caches and restores the Gradle Wrapper distribution downloaded to `~/.gradle/wrapper` (in addition to the Gradle caches), so wrapper-based (`./gradlew`) builds don't re-download the Gradle distribution. The wrapper distribution is stored in a **separate** cache entry keyed only on `**/gradle-wrapper.properties`, so it stays cached across the frequent `*.gradle*` changes that rotate the main dependency cache key.
+
 For projects that require more advanced `Gradle` caching features, such as caching build outputs, support for Gradle configuration cache, encrypted cache storage, fine-grained cache control (including options to enable or disable the cache, set it to read-only or write-only, perform automated cleanup, and define custom cache rules), or optimized performance for complex CI workflows, consider using [`gradle/actions/setup-gradle`](https://github.com/gradle/actions/tree/main/setup-gradle).  
 
 For setup details and a comprehensive overview of all available features, visit the [setup-gradle documentation](https://github.com/gradle/actions/blob/main/docs/setup-gradle.md).

__tests__/cache.test.ts

@@ -113,10 +113,7 @@ describe('dependency cache', () => {
 
         await restore('maven', '');
         expect(spyCacheRestore).toHaveBeenCalledWith(
-          [
-            join(os.homedir(), '.m2', 'repository'),
-            join(os.homedir(), '.m2', 'wrapper', 'dists')
-          ],
+          [join(os.homedir(), '.m2', 'repository')],
           expect.any(String)
         );
         expect(spyGlobHashFiles).toHaveBeenCalledWith(
@@ -143,10 +140,7 @@ describe('dependency cache', () => {
 
         await restore('maven', '');
         expect(spyCacheRestore).toHaveBeenCalledWith(
-          [
-            join(os.homedir(), '.m2', 'repository'),
-            join(os.homedir(), '.m2', 'wrapper', 'dists')
-          ],
+          [join(os.homedir(), '.m2', 'repository')],
           expect.any(String)
         );
         expect(spyGlobHashFiles).toHaveBeenCalledWith(
@@ -161,10 +155,7 @@ describe('dependency cache', () => {
 
         await restore('maven', '');
         expect(spyCacheRestore).toHaveBeenCalledWith(
-          [
-            join(os.homedir(), '.m2', 'repository'),
-            join(os.homedir(), '.m2', 'wrapper', 'dists')
-          ],
+          [join(os.homedir(), '.m2', 'repository')],
           expect.any(String)
         );
         expect(spyGlobHashFiles).toHaveBeenCalledWith(
@@ -173,6 +164,39 @@ describe('dependency cache', () => {
         expect(spyWarning).not.toHaveBeenCalled();
         expect(spyInfo).toHaveBeenCalledWith('maven cache is not found');
       });
+      it('restores the maven wrapper distribution cache independently of the main cache', async () => {
+        createFile(join(workspace, 'pom.xml'));
+        createDirectory(join(workspace, '.mvn'));
+        createDirectory(join(workspace, '.mvn', 'wrapper'));
+        createFile(
+          join(workspace, '.mvn', 'wrapper', 'maven-wrapper.properties')
+        );
+
+        await restore('maven', '');
+        // Main cache no longer includes the wrapper distribution.
+        expect(spyCacheRestore).toHaveBeenCalledWith(
+          [join(os.homedir(), '.m2', 'repository')],
+          expect.any(String)
+        );
+        // Wrapper distribution is restored on its own, keyed only on the
+        // maven-wrapper.properties hash.
+        expect(spyCacheRestore).toHaveBeenCalledWith(
+          [join(os.homedir(), '.m2', 'wrapper', 'dists')],
+          expect.any(String)
+        );
+        expect(spyGlobHashFiles).toHaveBeenCalledWith(
+          '**/.mvn/wrapper/maven-wrapper.properties'
+        );
+      });
+      it('skips the maven wrapper cache when no maven-wrapper.properties exists', async () => {
+        createFile(join(workspace, 'pom.xml'));
+
+        await restore('maven', '');
+        expect(spyCacheRestore).not.toHaveBeenCalledWith(
+          [join(os.homedir(), '.m2', 'wrapper', 'dists')],
+          expect.any(String)
+        );
+      });
     });
     describe('for gradle', () => {
       it('throws error if no build.gradle found', async () => {
@@ -228,6 +252,30 @@ describe('dependency cache', () => {
         expect(spyWarning).not.toHaveBeenCalled();
         expect(spyInfo).toHaveBeenCalledWith('gradle cache is not found');
       });
+      it('restores the gradle wrapper distribution cache independently of the main cache', async () => {
+        createFile(join(workspace, 'build.gradle'));
+        createDirectory(join(workspace, 'gradle'));
+        createDirectory(join(workspace, 'gradle', 'wrapper'));
+        createFile(
+          join(workspace, 'gradle', 'wrapper', 'gradle-wrapper.properties')
+        );
+
+        await restore('gradle', '');
+        // Main cache no longer includes the wrapper distribution.
+        expect(spyCacheRestore).toHaveBeenCalledWith(
+          [join(os.homedir(), '.gradle', 'caches')],
+          expect.any(String)
+        );
+        // Wrapper distribution is restored on its own, keyed only on the
+        // gradle-wrapper.properties hash.
+        expect(spyCacheRestore).toHaveBeenCalledWith(
+          [join(os.homedir(), '.gradle', 'wrapper')],
+          expect.any(String)
+        );
+        expect(spyGlobHashFiles).toHaveBeenCalledWith(
+          '**/gradle-wrapper.properties'
+        );
+      });
     });
     describe('for sbt', () => {
       it('throws error if no build.sbt found', async () => {
@@ -399,6 +447,40 @@ describe('dependency cache', () => {
           expect.stringMatching(/^Cache saved with the key:.*/)
         );
       });
+      it('saves the maven wrapper distribution cache under its own key', async () => {
+        createFile(join(workspace, 'pom.xml'));
+        createStateForWrapperRestore('maven-wrapper', false);
+
+        await save('maven');
+        expect(spyCacheSave).toHaveBeenCalledWith(
+          [join(os.homedir(), '.m2', 'wrapper', 'dists')],
+          'setup-java-maven-wrapper-primary-key'
+        );
+      });
+      it('does not save the maven wrapper cache on an exact wrapper hit', async () => {
+        createFile(join(workspace, 'pom.xml'));
+        createStateForWrapperRestore('maven-wrapper', true);
+
+        await save('maven');
+        expect(spyCacheSave).not.toHaveBeenCalledWith(
+          [join(os.homedir(), '.m2', 'wrapper', 'dists')],
+          expect.any(String)
+        );
+      });
+      it('does not fail the post step when the wrapper distribution path is missing', async () => {
+        createFile(join(workspace, 'pom.xml'));
+        createStateForWrapperRestore('maven-wrapper', false);
+        spyCacheSave.mockImplementation((paths: string[], key: string) => {
+          if (paths.includes(join(os.homedir(), '.m2', 'wrapper', 'dists'))) {
+            return Promise.reject(
+              new cache.ValidationError('Path Validation Error')
+            );
+          }
+          return Promise.resolve(0);
+        });
+
+        await expect(save('maven')).resolves.not.toThrow();
+      });
     });
     describe('for gradle', () => {
       it('uploads cache even if no build.gradle found', async () => {
@@ -451,6 +533,26 @@ describe('dependency cache', () => {
           expect.stringMatching(/^Cache saved with the key:.*/)
         );
       });
+      it('saves the gradle wrapper distribution cache under its own key', async () => {
+        createFile(join(workspace, 'build.gradle'));
+        createStateForWrapperRestore('gradle-wrapper', false);
+
+        await save('gradle');
+        expect(spyCacheSave).toHaveBeenCalledWith(
+          [join(os.homedir(), '.gradle', 'wrapper')],
+          'setup-java-gradle-wrapper-primary-key'
+        );
+      });
+      it('does not save the gradle wrapper cache on an exact wrapper hit', async () => {
+        createFile(join(workspace, 'build.gradle'));
+        createStateForWrapperRestore('gradle-wrapper', true);
+
+        await save('gradle');
+        expect(spyCacheSave).not.toHaveBeenCalledWith(
+          [join(os.homedir(), '.gradle', 'wrapper')],
+          expect.any(String)
+        );
+      });
     });
     describe('for sbt', () => {
       it('uploads cache even if no build.sbt found', async () => {
@@ -528,6 +630,29 @@ function createStateForSuccessfulRestore() {
   });
 }
 
+/**
+ * Create states to emulate a restore process where an additional (wrapper)
+ * cache was restored. When `hit` is true the matched key equals the primary
+ * key, emulating an exact wrapper cache hit.
+ */
+function createStateForWrapperRestore(wrapperName: string, hit: boolean) {
+  const primaryKey = `setup-java-${wrapperName}-primary-key`;
+  jest.spyOn(core, 'getState').mockImplementation(name => {
+    switch (name) {
+      case 'cache-primary-key':
+        return 'setup-java-cache-primary-key';
+      case 'cache-matched-key':
+        return 'setup-java-cache-matched-key';
+      case `cache-primary-key-${wrapperName}`:
+        return primaryKey;
+      case `cache-matched-key-${wrapperName}`:
+        return hit ? primaryKey : '';
+      default:
+        return '';
+    }
+  });
+}
+
 function createFile(path: string) {
   core.info(`created a file at ${path}`);
   fs.writeFileSync(path, '');