Fix the creation of the Usage Report (#1101)

* Use the forEachTenant method to generate the report for each tenant.
* add a test to verify the functionality of getSystemUsageStatisticsWithTenants

Signed-off-by: Michael Herdt <Michael.Herdt@bosch.io>

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/SystemManagementTest.java

@@ -41,6 +41,16 @@ public class SystemManagementTest extends AbstractJpaIntegrationTest {
         assertThat(systemManagement.findTenants(PAGE).getContent()).hasSize(3);
     }
 
+    @Test
+    @Description("Ensures that getSystemUsageStatisticsWithTenants returns the usage of all tenants and not only the first 1000 (max page size).")
+    public void systemUsageReportCollectsStatisticsOfManyTenants() throws Exception {
+        // Prepare tenants
+        createTestTenantsForSystemStatistics(1050, 0, 0, 0);
+
+        final List<TenantUsage> tenants = systemManagement.getSystemUsageStatisticsWithTenants().getTenants();
+        assertThat(tenants).hasSize(1051); // +1 from the setup
+    }
+
     @Test
     @Description("Checks that the system report calculates correctly the artifact size of all tenants in the system. It ignores deleted software modules with their artifacts.")
     public void systemUsageReportCollectsArtifactsOfAllTenants() throws Exception {