Do not resolve LazyFuture from RemoteDockerImage#toString (#2930)

Author: bsideup

core/src/main/java/org/testcontainers/utility/LazyFuture.java

@@ -2,10 +2,10 @@
 
 import lombok.AccessLevel;
 import lombok.Getter;
-import lombok.experimental.Delegate;
 import org.rnorth.ducttape.timeouts.Timeouts;
 
 import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Future implementation with lazy result evaluation <b>in the same Thread</b> as caller.
@@ -14,31 +14,37 @@
  */
 public abstract class LazyFuture<T> implements Future<T> {
 
-    @Delegate(excludes = Excludes.class)
-    private final Future<T> delegate = CompletableFuture.completedFuture(null);
-
     @Getter(value = AccessLevel.MODULE, lazy = true)
     private final T resolvedValue = resolve();
 
     abstract protected T resolve();
 
     @Override
-    public T get() throws InterruptedException, ExecutionException {
+    public boolean cancel(boolean mayInterruptIfRunning) {
+        return false;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return false;
+    }
+
+    @Override
+    public boolean isDone() {
+        return ((AtomicReference<?>) resolvedValue).get() != null;
+    }
+
+    @Override
+    public T get() {
         return getResolvedValue();
     }
 
     @Override
-    public T get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
+    public T get(long timeout, TimeUnit unit) throws TimeoutException {
         try {
             return Timeouts.getWithTimeout((int) timeout, unit, this::get);
         } catch (org.rnorth.ducttape.TimeoutException e) {
             throw new TimeoutException(e.getMessage());
         }
     }
-
-    private interface Excludes<T> {
-        T get();
-
-        T get(long timeout, TimeUnit unit);
-    }
 }

core/src/test/java/org/testcontainers/images/RemoteDockerImageTest.java

@@ -6,8 +6,11 @@
 
 import org.junit.Test;
 import org.testcontainers.utility.Base58;
+import org.testcontainers.utility.LazyFuture;
 
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Future;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 public class RemoteDockerImageTest {
 
@@ -44,4 +47,31 @@ public void toStringDoesntResolveImageNameFuture()  {
         imageNameFuture.complete(imageName);
         assertThat(remoteDockerImage.toString(), containsString("imageName=" + imageName));
     }
+
+    @Test(timeout=5000L)
+    public void toStringDoesntResolveLazyFuture() throws Exception {
+        String imageName = Base58.randomString(8).toLowerCase();
+        AtomicBoolean resolved = new AtomicBoolean(false);
+        Future<String> imageNameFuture = new LazyFuture<String>() {
+            @Override
+            protected String resolve() {
+                resolved.set(true);
+                return imageName;
+            }
+        };
+
+        // verify that we've set up the test properly
+        assertFalse(imageNameFuture.isDone());
+
+        RemoteDockerImage remoteDockerImage = new RemoteDockerImage(imageNameFuture);
+        assertThat(remoteDockerImage.toString(), containsString("imageName=<resolving>"));
+
+        // Make sure the act of calling toString doesn't resolve the imageNameFuture
+        assertFalse(imageNameFuture.isDone());
+        assertFalse(resolved.get());
+
+        // Trigger resolve
+        imageNameFuture.get();
+        assertThat(remoteDockerImage.toString(), containsString("imageName=" + imageName));
+    }
 }