DATACOUCH-356 Fix cast issue in deleteAll (#201)

Plus a test.  I didn't notice that Douglas Six did basically the
same thing in another PR (this was a re-do of an earlier PR which
didn't quite do what we'd like).  So since I already had it done
and had a test, I closed that PR (#163) and added him to the author
list.

Also - repository.count() raises a NoSuchElementException after you
delete all the documents.  That seems like a bug, but we will deal
with that separately.

src/main/java/org/springframework/data/couchbase/repository/support/SimpleReactiveCouchbaseRepository.java

@@ -43,6 +43,8 @@ import reactor.core.publisher.Mono;
  * @author Subhashni Balakrishnan
  * @author Mark Paluch
  * @author Christoph Strobl
+ * @author David Kelly
+ * @author Douglas Six
  * @since 3.0
  */
 public class SimpleReactiveCouchbaseRepository<T, ID extends Serializable> implements ReactiveCouchbaseRepository<T, ID> {
@@ -249,10 +251,9 @@ public class SimpleReactiveCouchbaseRepository<T, ID extends Serializable> imple
 
 
         return mapMono(operations.queryView(query)
-                .map(AsyncViewResult::rows)
+                .flatMap(AsyncViewResult::rows)
                 .flatMap(row -> {
-                    AsyncViewRow asyncViewRow = (AsyncViewRow) row;
-                    return operations.remove(asyncViewRow.id())
+                    return operations.remove(row.id())
                             .onErrorResumeNext(throwable -> {
                                 if (throwable instanceof DocumentDoesNotExistException) {
                                     return Observable.empty();

src/test/java/org/springframework/data/couchbase/repository/SimpleReactiveCouchbaseRepositoryDeleteAllIntegrationTests.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.data.couchbase.repository;
+
+import com.couchbase.client.java.Bucket;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TestName;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.couchbase.ContainerResourceRunner;
+import org.springframework.data.couchbase.ReactiveIntegrationTestApplicationConfig;
+import org.springframework.data.couchbase.repository.config.ReactiveRepositoryOperationsMapping;
+import org.springframework.data.couchbase.repository.support.IndexManager;
+import org.springframework.data.couchbase.repository.support.ReactiveCouchbaseRepositoryFactory;
+import org.springframework.data.repository.core.support.ReactiveRepositoryFactorySupport;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.TestExecutionListeners;
+import reactor.core.publisher.Mono;
+
+import java.util.NoSuchElementException;
+
+import static junit.framework.TestCase.fail;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.springframework.data.couchbase.CouchbaseTestHelper.getRepositoryWithRetry;
+
+/**
+ * @author David Kelly
+ */
+@RunWith(ContainerResourceRunner.class)
+@ContextConfiguration(classes = ReactiveIntegrationTestApplicationConfig.class)
+@TestExecutionListeners(SimpleReactiveCouchbaseRepositoryListener.class)
+public class SimpleReactiveCouchbaseRepositoryDeleteAllIntegrationTests {
+    // We do these tests here, rather in the simple crud tests, so we don't interact
+    // with those tests that make assumptions about what documents should be
+    // in the repo.
+    @Rule
+    public TestName testName = new TestName();
+
+    @Autowired
+    private Bucket client;
+
+    @Autowired
+    private ReactiveRepositoryOperationsMapping operationsMapping;
+
+    @Autowired
+    private IndexManager indexManager;
+
+    private ReactiveUserRepository repository;
+
+    private long getCount() {
+        return repository.count().block().longValue();
+    }
+
+    @Before
+    public void setup() throws Exception {
+        ReactiveRepositoryFactorySupport factory = new ReactiveCouchbaseRepositoryFactory(operationsMapping, indexManager);
+        repository = getRepositoryWithRetry(factory, ReactiveUserRepository.class);
+    }
+
+    @Test
+    public void simpleDeleteAll() {
+        String key = "my_unique_user_key";
+        ReactiveUser instance = new ReactiveUser(key, "foobar", 22);
+        repository.save(instance).block();
+
+        // we put a doc in, lets be sure the count reflects that there is
+        // at least one doc in there...
+        assertTrue(getCount() > 0L);
+
+        repository.deleteAll().block();
+
+        try {
+            getCount();
+            fail("count returned documents!");
+        } catch (NoSuchElementException e) {
+        }
+     }
+}