Add a test case that proves issue #1318.

server/src/test/java/io/spine/server/model/HandlerMapTest.java

@@ -20,17 +20,23 @@
 
 package io.spine.server.model;
 
+import io.spine.base.Identifier;
+import io.spine.model.contexts.projects.ProjectId;
+import io.spine.model.contexts.projects.command.SigCreateProject;
+import io.spine.server.BoundedContextBuilder;
 import io.spine.server.command.model.CommandHandlerSignature;
 import io.spine.server.model.given.map.DupEventFilterValue;
 import io.spine.server.model.given.map.DupEventFilterValueWhere;
 import io.spine.server.model.given.map.DuplicateCommandHandlers;
+import io.spine.server.model.given.map.RejectionsDispatchingTestEnv;
 import io.spine.server.model.given.map.TwoFieldsInSubscription;
 import io.spine.server.model.given.method.OneParamSignature;
 import io.spine.server.model.given.method.StubHandler;
 import io.spine.server.type.EventClass;
 import io.spine.string.StringifierRegistry;
 import io.spine.string.Stringifiers;
 import io.spine.test.event.ProjectStarred;
+import io.spine.testing.server.blackbox.ContextAwareTest;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
@@ -97,4 +103,30 @@ void failIfNotFound() {
         assertThrows(IllegalStateException.class,
                      () -> map.handlerOf(EventClass.from(ProjectStarred.class)));
     }
+
+    @Nested
+    @DisplayName("gracefully handle a missing handler for a rejection with a specific origin")
+    class SpecificRejection extends ContextAwareTest {
+
+        @Override
+        protected BoundedContextBuilder contextBuilder() {
+            return BoundedContextBuilder
+                    .assumingTests()
+                    .add(RejectionsDispatchingTestEnv.ProjectAgg.class)
+                    .addEventDispatcher(new RejectionsDispatchingTestEnv.CompletionWatch());
+        }
+
+        @Test
+        void handleThrownRejectionGracefully() {
+            ProjectId project = ProjectId
+                    .newBuilder()
+                    .setId(Identifier.newUuid())
+                    .vBuild();
+            SigCreateProject createProject = SigCreateProject
+                    .newBuilder()
+                    .setId(project)
+                    .vBuild();
+            context().receivesCommand(createProject);
+        }
+    }
 }

server/src/test/java/io/spine/server/model/given/map/RejectionsDispatchingTestEnv.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.server.model.given.map;
+
+import io.spine.core.Subscribe;
+import io.spine.model.contexts.projects.Project;
+import io.spine.model.contexts.projects.ProjectId;
+import io.spine.model.contexts.projects.command.SigCreateProject;
+import io.spine.model.contexts.projects.command.SigStartProject;
+import io.spine.model.contexts.projects.event.SigProjectCreated;
+import io.spine.model.contexts.projects.event.SigProjectStarted;
+import io.spine.model.contexts.projects.rejection.ProjectRejections;
+import io.spine.model.contexts.projects.rejection.SigProjectAlreadyCompleted;
+import io.spine.server.aggregate.Aggregate;
+import io.spine.server.aggregate.Apply;
+import io.spine.server.command.Assign;
+import io.spine.server.event.AbstractEventSubscriber;
+
+public final class RejectionsDispatchingTestEnv {
+
+    private RejectionsDispatchingTestEnv() {
+    }
+
+    /**
+     * A test aggregate that throws {@link SigProjectAlreadyCompleted} rejection for any
+     * handled command.
+     */
+    public static final class ProjectAgg extends Aggregate<ProjectId, Project, Project.Builder> {
+
+        @Assign
+        SigProjectStarted handle(SigStartProject c) throws SigProjectAlreadyCompleted {
+            throw SigProjectAlreadyCompleted
+                    .newBuilder()
+                    .setProject(c.getId())
+                    .build();
+        }
+
+        @Assign
+        SigProjectCreated handle(SigCreateProject c) throws SigProjectAlreadyCompleted {
+            throw SigProjectAlreadyCompleted
+                    .newBuilder()
+                    .setProject(c.getId())
+                    .build();
+        }
+
+        @Apply
+        private void on(SigProjectStarted e) {
+            // do nothing.
+        }
+
+        @Apply
+        private void on(SigProjectCreated e) {
+            // do nothing.
+        }
+    }
+
+    /**
+     * A test environment for the rejection subscriptions tests.
+     *
+     * <p>The subscriber is interested in the rejection thrown upon trying to
+     * {@linkplain SigStartProject start} the project, but not in rejections thrown when the project
+     * is just being {@linkplain SigCreateProject created}.
+     */
+    public static final class CompletionWatch extends AbstractEventSubscriber {
+
+        @Subscribe
+        void on(ProjectRejections.SigProjectAlreadyCompleted rejection, SigStartProject cmd) {
+            // do nothing.
+        }
+    }
+}

server/src/test/proto/spine/test/model/contexts/projects/rejections.proto

@@ -42,3 +42,7 @@ message SigOwnerAlreadyAssigned {
     ProjectId project_id = 1;
     core.UserId current_owner = 2;
 }
+
+message SigProjectAlreadyCompleted {
+    ProjectId project = 1;
+}