1 files changed, 138 insertions, 0 deletions
diff --git a/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodUtils.java b/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodUtils.java
index 19c1bffaebcd..3e2c4051b792 100644
--- a/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodUtils.java
+++ b/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodUtils.java
@@ -15,7 +15,20 @@
  */
 package android.platform.test.ravenwood;
 
+import static com.android.ravenwood.common.RavenwoodCommonUtils.ReflectedMethod.reflectMethod;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.os.Handler;
+import android.os.Looper;
+
 import com.android.ravenwood.common.RavenwoodCommonUtils;
+import com.android.ravenwood.common.SneakyThrow;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Supplier;
 
 /**
  * Utilities for writing (bivalent) ravenwood tests.
@@ -47,4 +60,129 @@ public class RavenwoodUtils {
     public static void loadJniLibrary(String libname) {
         RavenwoodCommonUtils.loadJniLibrary(libname);
     }
+
+    private class MainHandlerHolder {
+        static Handler sMainHandler = new Handler(Looper.getMainLooper());
+    }
+
+    /**
+     * Returns the main thread handler.
+     */
+    public static Handler getMainHandler() {
+        return MainHandlerHolder.sMainHandler;
+    }
+
+    /**
+     * Run a Callable on Handler and wait for it to complete.
+     */
+    @Nullable
+    public static <T> T runOnHandlerSync(@NonNull Handler h, @NonNull Callable<T> c) {
+        var result = new AtomicReference<T>();
+        var thrown = new AtomicReference<Throwable>();
+        var latch = new CountDownLatch(1);
+        h.post(() -> {
+            try {
+                result.set(c.call());
+            } catch (Throwable th) {
+                thrown.set(th);
+            }
+            latch.countDown();
+        });
+        try {
+            latch.await();
+        } catch (InterruptedException e) {
+            throw new RuntimeException("Interrupted while waiting on the Runnable", e);
+        }
+        var th = thrown.get();
+        if (th != null) {
+            SneakyThrow.sneakyThrow(th);
+        }
+        return result.get();
+    }
+
+
+    /**
+     * Run a Runnable on Handler and wait for it to complete.
+     */
+    @Nullable
+    public static void runOnHandlerSync(@NonNull Handler h, @NonNull Runnable r) {
+        runOnHandlerSync(h, () -> {
+            r.run();
+            return null;
+        });
+    }
+
+    /**
+     * Run a Callable on main thread and wait for it to complete.
+     */
+    @Nullable
+    public static <T> T runOnMainThreadSync(@NonNull Callable<T> c) {
+        return runOnHandlerSync(getMainHandler(), c);
+    }
+
+    /**
+     * Run a Runnable on main thread and wait for it to complete.
+     */
+    @Nullable
+    public static void runOnMainThreadSync(@NonNull Runnable r) {
+        runOnHandlerSync(getMainHandler(), r);
+    }
+
+    public static class MockitoHelper {
+        private MockitoHelper() {
+        }
+
+        /**
+         * Allow verifyZeroInteractions to work on ravenwood. It was replaced with a different
+         * method on. (Maybe we should do it in Ravenizer.)
+         */
+        public static void verifyZeroInteractions(Object... mocks) {
+            if (RavenwoodRule.isOnRavenwood()) {
+                // Mockito 4 or later
+                reflectMethod("org.mockito.Mockito", "verifyNoInteractions", Object[].class)
+                        .callStatic(new Object[]{mocks});
+            } else {
+                // Mockito 2
+                reflectMethod("org.mockito.Mockito", "verifyZeroInteractions", Object[].class)
+                        .callStatic(new Object[]{mocks});
+            }
+        }
+    }
+
+
+    /**
+     * Wrap the given {@link Supplier} to become memoized.
+     *
+     * The underlying {@link Supplier} will only be invoked once, and that result will be cached
+     * and returned for any future requests.
+     */
+    static <T> Supplier<T> memoize(ThrowingSupplier<T> supplier) {
+        return new Supplier<>() {
+            private T mInstance;
+
+            @Override
+            public T get() {
+                synchronized (this) {
+                    if (mInstance == null) {
+                        mInstance = create();
+                    }
+                    return mInstance;
+                }
+            }
+
+            private T create() {
+                try {
+                    return supplier.get();
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        };
+    }
+
+    /** Used by {@link #memoize(ThrowingSupplier)}  */
+    public interface ThrowingSupplier<T> {
+        /** */
+        T get() throws Exception;
+    }
 }