diff --git a/src/test/java/net/hostsharing/hsadminng/hscustomer/CustomerRepositoryIntegrationTest.java b/src/test/java/net/hostsharing/hsadminng/hscustomer/CustomerRepositoryIntegrationTest.java
index 370b2ad0..642405dd 100644
--- a/src/test/java/net/hostsharing/hsadminng/hscustomer/CustomerRepositoryIntegrationTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hscustomer/CustomerRepositoryIntegrationTest.java
@@ -1,26 +1,26 @@
 package net.hostsharing.hsadminng.hscustomer;
 
 import net.hostsharing.hsadminng.context.Context;
+import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
 import org.springframework.context.annotation.ComponentScan;
+import org.springframework.core.NestedRuntimeException;
 import org.springframework.orm.jpa.JpaSystemException;
 
 import javax.persistence.EntityManager;
 import javax.transaction.Transactional;
+import java.util.List;
 import java.util.Optional;
+import java.util.function.Supplier;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.assertThrows;
 
 @DataJpaTest
 @ComponentScan(basePackageClasses = { Context.class, CustomerRepository.class })
 class CustomerRepositoryIntegrationTest {
 
-    final static String adminUser = "mike@hostsharing.net";
-    final static String customerAaa = "admin@aaa.example.com";
-
     @Autowired
     Context context;
 
@@ -29,127 +29,154 @@ class CustomerRepositoryIntegrationTest {
 
     @Autowired EntityManager em;
 
-    @Test
-    @Transactional
-    void hostsharingAdminWithoutAssumedRoleCanViewAllCustomers() {
-        // given
-        context.setCurrentUser(adminUser);
+    @Nested
+    class FindAll {
 
-        // when
-        final var actual = customerRepository.findAll();
+        private final Given given = new Given();
+        private When<List<CustomerEntity>> when;
+        private final Then then = new Then();
 
-        // then
+        @Test
+        public void hostsharingAdminWithoutAssumedRoleCanViewAllCustomers() {
+            given.currentUser("mike@hostsharing.net");
 
-        assertThat(actual).hasSize(3)
-            .extracting(CustomerEntity::getPrefix)
-            .containsExactlyInAnyOrder("aaa", "aab", "aac");
+            when(() -> customerRepository.findAll());
+
+            then.exactlyTheseCustomersAreReturned("aaa", "aab", "aac");
+        }
+
+        @Test
+        public void hostsharingAdminWithAssumedHostsharingAdminRoleCanViewAllCustomers() {
+            given.currentUser("mike@hostsharing.net").
+                and().assumedRoles("global#hostsharing.admin");
+
+            when(() -> customerRepository.findAll());
+
+            then.exactlyTheseCustomersAreReturned("aaa", "aab", "aac");
+        }
+
+        @Test
+        public void customerAdminWithoutAssumedRoleCanViewOnlyItsOwnCustomer() {
+            given.currentUser("admin@aaa.example.com");
+
+            when(() -> customerRepository.findAll());
+
+            then.exactlyTheseCustomersAreReturned("aaa");
+        }
+
+        @Test
+        public void customerAdminWithAssumedOwnedPackageAdminRoleCanViewOnlyItsOwnCustomer() {
+            given.currentUser("admin@aaa.example.com").
+                and().assumedRoles("package#aaa00.admin");
+
+            when(() -> customerRepository.findAll());
+
+            then.exactlyTheseCustomersAreReturned("aaa");
+        }
+
+        @Test
+        public void customerAdmin_withAssumedAlienPackageAdminRole_cannotViewAnyCustomer() {
+            given.currentUser("admin@aaa.example.com").
+                and().assumedRoles("package#aab00.admin");
+
+            when(() -> customerRepository.findAll());
+
+            then.expectJpaSystemExceptionHasBeenThrown().
+                and()
+                .expectRootCauseMessageMatches(
+                    ".* user admin@aaa.example.com .* has no permission to assume role package#aab00#admin .*");
+        }
+
+        @Test
+        void unknownUser_withoutAssumedRole_cannotViewAnyCustomers() {
+            given.currentUser("unknown@example.org");
+
+            when(() -> customerRepository.findAll());
+
+            then.expectJpaSystemExceptionHasBeenThrown().
+                and().expectRootCauseMessageMatches(".* user unknown@example.org does not exist.*");
+        }
+
+        @Test
+        @Transactional
+        void unknownUserWithAssumedCustomerRoleCannotViewAnyCustomers() {
+            given.currentUser("unknown@example.org").
+                and().assumedRoles("customer#aaa.admin");
+
+            when(() -> customerRepository.findAll());
+
+            then.expectJpaSystemExceptionHasBeenThrown().
+                and().expectRootCauseMessageMatches(".* user unknown@example.org does not exist.*");
+        }
+
+        void when(final Supplier<List<CustomerEntity>> code) {
+            try {
+                when = new When<>(code.get());
+            } catch (final NestedRuntimeException exc) {
+                when = new When<>(exc);
+            }
+        }
+
+        private class Then {
+
+            Then and() {
+                return this;
+            }
+
+            void exactlyTheseCustomersAreReturned(final String... customerPrefixes) {
+                assertThat(when.actualResult)
+                    .hasSize(customerPrefixes.length)
+                    .extracting(CustomerEntity::getPrefix)
+                    .containsExactlyInAnyOrder(customerPrefixes);
+            }
+
+            Then expectJpaSystemExceptionHasBeenThrown() {
+                assertThat(when.actualException).isInstanceOf(JpaSystemException.class);
+                return this;
+            }
+
+            void expectRootCauseMessageMatches(final String expectedMessage) {
+                assertThat(firstRootCauseMessageLineOf(when.actualException)).matches(expectedMessage);
+            }
+        }
     }
 
-    @Test
-    @Transactional
-    void hostsharingAdminWithAssumedHostsharingAdminRoleCanViewAllCustomers() {
-        // given
-        context.setCurrentUser(adminUser);
-        context.assumeRoles("global#hostsharing.admin");
-
-        // when
-        final var actual = customerRepository.findAll();
-
-        // then
-
-        assertThat(actual).hasSize(3)
-            .extracting(CustomerEntity::getPrefix)
-            .containsExactlyInAnyOrder("aaa", "aab", "aac");
-    }
-
-    @Test
-    @Transactional
-    void customerAdminWithoutAssumedRoleCanViewItsOwnCustomer() {
-        // given
-        context.setCurrentUser(customerAaa);
-
-        // when
-        final var actual = customerRepository.findAll();
-
-        // then
-
-        assertThat(actual).hasSize(1)
-            .extracting(CustomerEntity::getPrefix)
-            .containsExactly("aaa");
-    }
-
-    @Test
-    @Transactional
-    void customerAdminWithAssumedOwnedPackageAdminRoleCanViewItsOwnCustomer() {
-        // given
-        context.setCurrentUser(customerAaa);
-        context.assumeRoles("package#aaa00.admin");
-
-        // when
-        final var actual = customerRepository.findAll();
-
-        // then
-        assertThat(actual).hasSize(1)
-            .extracting(CustomerEntity::getPrefix)
-            .containsExactly("aaa");
-    }
-
-    @Test
-    @Transactional
-    void customerAdminWithAssumedAlienPackageAdminRoleCanViewItsOwnCustomer() {
-        // given
-        context.setCurrentUser(customerAaa);
-        context.assumeRoles("package#aab00.admin");
-
-        // when
-        final JpaSystemException thrown =
-            assertThrows(JpaSystemException.class, () -> customerRepository.findAll());
-
-        // then
-        assertThat(firstRootCauseMessageLineOf(thrown)).matches(
-            ".* user admin@aaa.example.com .* has no permission to assume role package#aab00#admin .*"
-        );
-   }
-
-    @Test
-    @Transactional
-    void unknownUserWithoutAssumedRoleCannotViewAnyCustomers() {
-        // given
-        context.setCurrentUser("unknown@example.org");
-
-        // when
-        final JpaSystemException thrown =
-            assertThrows(JpaSystemException.class, () -> customerRepository.findAll());
-
-        // then
-        assertThat(firstRootCauseMessageLineOf(thrown)).matches(
-            ".* user unknown@example.org does not exist.*"
-        );
-    }
-
-    @Test
-    @Transactional
-    void unknownUserWithAssumedRoleCannotViewAnyCustomers() {
-        // given
-        context.setCurrentUser("unknown@example.org");
-        assertThat(context.getCurrentUser()).isEqualTo("unknown@example.org");
-        context.assumeRoles("customer#aaa.admin");
-
-
-        // when
-        final JpaSystemException thrown =
-            assertThrows(JpaSystemException.class, () -> customerRepository.findAll());
-
-        // then
-        assertThat(firstRootCauseMessageLineOf(thrown)).matches(
-            ".* user unknown@example.org does not exist.*"
-        );
-    }
-
-    private String firstRootCauseMessageLineOf(final JpaSystemException throwable) {
-        return Optional.ofNullable(throwable.getRootCause())
+    private String firstRootCauseMessageLineOf(final NestedRuntimeException exception) {
+        return Optional.ofNullable(exception.getRootCause())
             .map(Throwable::getMessage)
-            .map( message -> message.split("\\r|\\n|\\r\\n", 0)[0])
-        .orElse(null);
+            .map(message -> message.split("\\r|\\n|\\r\\n", 0)[0])
+            .orElse(null);
+    }
+
+    private class Given {
+
+        Given and() {
+            return this;
+        }
+
+        Given currentUser(final String currentUser) {
+            context.setCurrentUser(currentUser);
+            assertThat(context.getCurrentUser()).as("precondition").isEqualTo(currentUser);
+            return this;
+        }
+
+        void assumedRoles(final String assumedRoles) {
+            context.assumeRoles(assumedRoles);
+            assertThat(context.getAssumedRoles()).as("precondition").containsExactly(assumedRoles.split(";"));
+        }
+    }
+
+    private static class When<T> {
+
+        T actualResult;
+        NestedRuntimeException actualException;
+
+        When(final T actualResult) {
+            this.actualResult = actualResult;
+        }
+
+        When(final NestedRuntimeException exception) {
+            this.actualException = exception;
+        }
     }
 }