Add a check for whether the tenant id is set or not

modules/flowable-engine-common-api/src/main/java/org/flowable/common/engine/api/tenant/TenantContext.java

@@ -38,4 +38,11 @@ public interface TenantContext {
      */
     void clearTenantId();
 
+    /**
+     * Flag indicating whether the tenant id is set.
+     *
+     * @return {@code true} if the tenant id can return a value for {@link #getTenantId()}, {@code false} otherwise
+     */
+    boolean isTenantIdSet();
+
 }

modules/flowable-engine-common/src/main/java/org/flowable/common/engine/impl/tenant/ThreadLocalTenantContext.java

@@ -23,6 +23,7 @@ public class ThreadLocalTenantContext implements TenantContext {
     protected final ThreadLocal<String> tenantId = ThreadLocal.withInitial(() -> {
         throw new FlowableException("Tenant value has not been set");
     });
+    protected final ThreadLocal<Boolean> tenantIdSet = ThreadLocal.withInitial(() -> Boolean.FALSE);
 
     @Override
     public String getTenantId() {
@@ -32,11 +33,17 @@ public String getTenantId() {
     @Override
     public void setTenantId(String tenantId) {
         this.tenantId.set(tenantId);
+        this.tenantIdSet.set(true);
     }
 
     @Override
     public void clearTenantId() {
         tenantId.remove();
+        tenantIdSet.remove();
     }
 
+    @Override
+    public boolean isTenantIdSet() {
+        return tenantIdSet.get();
+    }
 }

modules/flowable-engine-common/src/test/java/org/flowable/common/engine/impl/tenant/ThreadLocalTenantContextTest.java

@@ -0,0 +1,57 @@
+/* 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 org.flowable.common.engine.impl.tenant;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import org.flowable.common.engine.api.FlowableException;
+import org.flowable.common.engine.api.tenant.TenantContext;
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author Filip Hrisafov
+ */
+class ThreadLocalTenantContextTest {
+
+    protected TenantContext underTest = new ThreadLocalTenantContext();
+
+    @Test
+    void getTenantId() {
+        assertThatThrownBy(() -> underTest.getTenantId())
+                .isExactlyInstanceOf(FlowableException.class)
+                .hasMessage("Tenant value has not been set");
+
+        underTest.setTenantId("acme");
+        assertThat(underTest.getTenantId()).isEqualTo("acme");
+
+        underTest.setTenantId("muppets");
+        assertThat(underTest.getTenantId()).isEqualTo("muppets");
+
+        underTest.clearTenantId();
+        assertThatThrownBy(() -> underTest.getTenantId())
+                .isExactlyInstanceOf(FlowableException.class)
+                .hasMessage("Tenant value has not been set");
+    }
+
+    @Test
+    void isTenantIdSet() {
+        assertThat(underTest.isTenantIdSet()).isFalse();
+
+        underTest.setTenantId("flowable");
+        assertThat(underTest.isTenantIdSet()).isTrue();
+
+        underTest.clearTenantId();
+        assertThat(underTest.isTenantIdSet()).isFalse();
+    }
+}