1 files changed, 63 insertions, 0 deletions
diff --git a/vpp-common/vpp-translate-test/src/main/java/io/fd/honeycomb/vpp/test/util/FutureProducer.java b/vpp-common/vpp-translate-test/src/main/java/io/fd/honeycomb/vpp/test/util/FutureProducer.java
new file mode 100644
index 000000000..6a81549f2
--- /dev/null
+++ b/vpp-common/vpp-translate-test/src/main/java/io/fd/honeycomb/vpp/test/util/FutureProducer.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.vpp.test.util;
+
+import java.util.concurrent.CompletableFuture;
+import javax.annotation.Nonnull;
+import org.openvpp.jvpp.VppCallbackException;
+import org.openvpp.jvpp.core.future.FutureJVppCore;
+
+/**
+ * <p>VPP translation test helper, that produces instances of {@link CompletableFuture} with desired results.</p>
+ * <p>Useful when stubbing {@link FutureJVppCore} methods: <br>{@code when(api.showVersion(any())).thenReturn(future(new
+ * ShowVersionReply()));}</p>
+ */
+public interface FutureProducer {
+
+    /**
+     * Returns {@link CompletableFuture} with desired result.
+     *
+     * @param result returned when {@link CompletableFuture#get()} is invoked
+     * @param <T>    the result type of returned future
+     */
+    default <T> CompletableFuture<T> future(@Nonnull final T result) {
+        final CompletableFuture<T> future = new CompletableFuture<>();
+        future.complete(result);
+        return future;
+    }
+
+    /**
+     * Returns {@link CompletableFuture} with provided {@link Exception} as a result.
+     *
+     * @param exception to be thrown when {@link CompletableFuture#get()} is invoked
+     * @param <T>       the result type of returned future
+     */
+    default <T> CompletableFuture<T> failedFuture(@Nonnull final Exception exception) {
+        final CompletableFuture<T> future = new CompletableFuture<>();
+        future.completeExceptionally(exception);
+        return future;
+    }
+
+    /**
+     * Returns {@link CompletableFuture} with VppCallbackException(retval = -1) as a cause.
+     *
+     * @param <T> the result type of returned future
+     */
+    default <T> CompletableFuture<T> failedFuture() {
+        return failedFuture(new VppCallbackException("test-call", 1 /* ctxId */, -1 /* retval */));
+    }
+}