src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionController.java

@@ -27,11 +27,13 @@ import java.util.UUID;
 import java.util.function.BiConsumer;
 
 import static java.util.Optional.ofNullable;
+import static net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionType.REVERSAL;
+import static net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionType.TRANSFER;
 import static net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeCoopAssetsTransactionTypeResource.CLEARING;
 import static net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeCoopAssetsTransactionTypeResource.DEPOSIT;
 import static net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeCoopAssetsTransactionTypeResource.DISBURSAL;
 import static net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeCoopAssetsTransactionTypeResource.LOSS;
-import static net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeCoopAssetsTransactionTypeResource.TRANSFER;
+import static net.hostsharing.hsadminng.lambda.WithNonNull.withNonNull;
 
 @RestController
 public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAssetsApi {
@@ -66,7 +68,10 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
                 fromValueDate,
                 toValueDate);
 
-        final var resources = mapper.mapList(entities, HsOfficeCoopAssetsTransactionResource.class, ENTITY_TO_RESOURCE_POSTMAPPER);
+        final var resources = mapper.mapList(
+                entities,
+                HsOfficeCoopAssetsTransactionResource.class,
+                ENTITY_TO_RESOURCE_POSTMAPPER);
         return ResponseEntity.ok(resources);
     }
 
@@ -106,7 +111,11 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
         if (result.isEmpty()) {
             return ResponseEntity.notFound().build();
         }
-        return ResponseEntity.ok(mapper.map(result.get(), HsOfficeCoopAssetsTransactionResource.class));
+        final var resource = mapper.map(
+                result.get(),
+                HsOfficeCoopAssetsTransactionResource.class,
+                ENTITY_TO_RESOURCE_POSTMAPPER);
+        return ResponseEntity.ok(resource);
 
     }
 
@@ -131,7 +140,8 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
     private static void validateCreditTransaction(
             final HsOfficeCoopAssetsTransactionInsertResource requestBody,
             final ArrayList<String> violations) {
-        if (List.of(DISBURSAL, TRANSFER, CLEARING, LOSS).contains(requestBody.getTransactionType())
+        if (List.of(DISBURSAL, HsOfficeCoopAssetsTransactionTypeResource.TRANSFER, CLEARING, LOSS)
+                .contains(requestBody.getTransactionType())
                 && requestBody.getAssetValue().signum() > 0) {
             violations.add("for %s, assetValue must be negative but is \"%.2f\"".formatted(
                     requestBody.getTransactionType(), requestBody.getAssetValue()));
@@ -147,57 +157,108 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
         }
     }
 
+    // TODO.refa: this logic needs to get extracted to a service
     final BiConsumer<HsOfficeCoopAssetsTransactionEntity, HsOfficeCoopAssetsTransactionResource> ENTITY_TO_RESOURCE_POSTMAPPER = (entity, resource) -> {
         resource.setMembershipUuid(entity.getMembership().getUuid());
         resource.setMembershipMemberNumber(entity.getMembership().getTaggedMemberNumber());
 
-        if (entity.getReversalAssetTx() != null) {
+        withNonNull(
-            resource.getReversalAssetTx().setRevertedAssetTxUuid(entity.getUuid());
+                resource.getReversalAssetTx(), reversalAssetTxResource -> {
-            resource.getReversalAssetTx().setMembershipUuid(entity.getMembership().getUuid());
+                    reversalAssetTxResource.setMembershipUuid(entity.getMembership().getUuid());
-            resource.getReversalAssetTx().setMembershipMemberNumber(entity.getTaggedMemberNumber());
+                    reversalAssetTxResource.setMembershipMemberNumber(entity.getTaggedMemberNumber());
-        }
+                    reversalAssetTxResource.setRevertedAssetTxUuid(entity.getUuid());
+                    withNonNull(
+                            entity.getAdoptionAssetTx(), adoptionAssetTx ->
+                                    reversalAssetTxResource.setAdoptionAssetTxUuid(adoptionAssetTx.getUuid()));
+                    withNonNull(
+                            entity.getTransferAssetTx(), transferAssetTxResource ->
+                                    reversalAssetTxResource.setTransferAssetTxUuid(transferAssetTxResource.getUuid()));
+                });
 
-        if (entity.getRevertedAssetTx() != null) {
+        withNonNull(
-            resource.getRevertedAssetTx().setReversalAssetTxUuid(entity.getUuid());
+                resource.getRevertedAssetTx(), revertAssetTxResource -> {
-            resource.getRevertedAssetTx().setMembershipUuid(entity.getMembership().getUuid());
+                    revertAssetTxResource.setMembershipUuid(entity.getMembership().getUuid());
-            resource.getRevertedAssetTx().setMembershipMemberNumber(entity.getTaggedMemberNumber());
+                    revertAssetTxResource.setMembershipMemberNumber(entity.getTaggedMemberNumber());
-        }
+                    revertAssetTxResource.setReversalAssetTxUuid(entity.getUuid());
+                    withNonNull(
+                            entity.getRevertedAssetTx().getAdoptionAssetTx(), adoptionAssetTx ->
+                                    revertAssetTxResource.setAdoptionAssetTxUuid(adoptionAssetTx.getUuid()));
+                    withNonNull(
+                            entity.getRevertedAssetTx().getTransferAssetTx(), transferAssetTxResource ->
+                                    revertAssetTxResource.setTransferAssetTxUuid(transferAssetTxResource.getUuid()));
+                });
 
-        if (entity.getAdoptionAssetTx() != null) {
+        withNonNull(
-            resource.getAdoptionAssetTx().setTransferAssetTxUuid(entity.getUuid());
+                resource.getAdoptionAssetTx(), adoptionAssetTxResource -> {
-            resource.getAdoptionAssetTx().setMembershipUuid(entity.getAdoptionAssetTx().getMembership().getUuid());
+                    adoptionAssetTxResource.setMembershipUuid(entity.getAdoptionAssetTx().getMembership().getUuid());
-            resource.getAdoptionAssetTx().setMembershipMemberNumber(entity.getAdoptionAssetTx().getTaggedMemberNumber());
+                    adoptionAssetTxResource.setMembershipMemberNumber(entity.getAdoptionAssetTx().getTaggedMemberNumber());
-        }
+                    adoptionAssetTxResource.setTransferAssetTxUuid(entity.getUuid());
+                    withNonNull(
+                            entity.getAdoptionAssetTx().getReversalAssetTx(), reversalAssetTx ->
+                                    adoptionAssetTxResource.setReversalAssetTxUuid(reversalAssetTx.getUuid()));
+                });
 
-        if (entity.getTransferAssetTx() != null) {
+        withNonNull(
-            resource.getTransferAssetTx().setAdoptionAssetTxUuid(entity.getUuid());
+                resource.getTransferAssetTx(), transferAssetTxResource -> {
                     resource.getTransferAssetTx().setMembershipUuid(entity.getTransferAssetTx().getMembership().getUuid());
-            resource.getTransferAssetTx().setMembershipMemberNumber(entity.getTransferAssetTx().getTaggedMemberNumber());
+                    resource.getTransferAssetTx()
-        }
+                            .setMembershipMemberNumber(entity.getTransferAssetTx().getTaggedMemberNumber());
+                    resource.getTransferAssetTx().setAdoptionAssetTxUuid(entity.getUuid());
+                    withNonNull(
+                            entity.getTransferAssetTx().getReversalAssetTx(), reversalAssetTx ->
+                                    transferAssetTxResource.setReversalAssetTxUuid(reversalAssetTx.getUuid()));
+                });
     };
 
+    // TODO.refa: this logic needs to get extracted to a service
     final BiConsumer<HsOfficeCoopAssetsTransactionInsertResource, HsOfficeCoopAssetsTransactionEntity> RESOURCE_TO_ENTITY_POSTMAPPER = (resource, entity) -> {
 
         if (resource.getMembershipUuid() != null) {
-            final HsOfficeMembershipEntity membership = ofNullable(emw.find(HsOfficeMembershipEntity.class, resource.getMembershipUuid()))
+            final HsOfficeMembershipEntity membership = ofNullable(emw.find(
-                    .orElseThrow(() -> new EntityNotFoundException("ERROR: [400] membership.uuid %s not found".formatted(
+                    HsOfficeMembershipEntity.class,
+                    resource.getMembershipUuid()))
+                    .orElseThrow(() -> new EntityNotFoundException("membership.uuid %s not found".formatted(
                             resource.getMembershipUuid())));
             entity.setMembership(membership);
         }
-        if (resource.getRevertedAssetTxUuid() != null) {
+
+        if (entity.getTransactionType() == REVERSAL) {
+            if (resource.getRevertedAssetTxUuid() == null) {
+                throw new ValidationException("REVERSAL asset transaction requires revertedAssetTx.uuid");
+            }
             final var revertedAssetTx = coopAssetsTransactionRepo.findByUuid(resource.getRevertedAssetTxUuid())
-                    .orElseThrow(() -> new EntityNotFoundException("ERROR: [400] revertedEntityUuid %s not found".formatted(
+                    .orElseThrow(() -> new EntityNotFoundException("revertedAssetTx.uuid %s not found".formatted(
                             resource.getRevertedAssetTxUuid())));
+            revertedAssetTx.setReversalAssetTx(entity);
             entity.setRevertedAssetTx(revertedAssetTx);
             if (resource.getAssetValue().negate().compareTo(revertedAssetTx.getAssetValue()) != 0) {
                 throw new ValidationException("given assetValue=" + resource.getAssetValue() +
                         " but must be negative value from reverted asset tx: " + revertedAssetTx.getAssetValue());
             }
+
+            if (revertedAssetTx.getTransactionType() == TRANSFER) {
+                final var adoptionAssetTx = revertedAssetTx.getAdoptionAssetTx();
+                final var adoptionReversalAssetTx = HsOfficeCoopAssetsTransactionEntity.builder()
+                        .transactionType(REVERSAL)
+                        .membership(adoptionAssetTx.getMembership())
+                        .revertedAssetTx(adoptionAssetTx)
+                        .assetValue(adoptionAssetTx.getAssetValue().negate())
+                        .comment(resource.getComment())
+                        .reference(resource.getReference())
+                        .valueDate(resource.getValueDate())
+                        .build();
+                adoptionAssetTx.setReversalAssetTx(adoptionReversalAssetTx);
+                adoptionReversalAssetTx.setRevertedAssetTx(adoptionAssetTx);
+            }
         }
 
+        if (resource.getTransactionType() == HsOfficeCoopAssetsTransactionTypeResource.TRANSFER) {
             final var adoptingMembership = determineAdoptingMembership(resource);
-        if (adoptingMembership != null) {
+            if ( entity.getMembership() == adoptingMembership) {
-            final var adoptingAssetTx = coopAssetsTransactionRepo.save(createAdoptingAssetTx(entity, adoptingMembership));
+                throw new ValidationException("transferring and adopting membership must be different, but both are " +
+                        adoptingMembership.getTaggedMemberNumber());
+            }
+            final var adoptingAssetTx = createAdoptingAssetTx(entity, adoptingMembership);
             entity.setAdoptionAssetTx(adoptingAssetTx);
         }
     };
@@ -206,11 +267,11 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
         final var adoptingMembershipUuid = resource.getAdoptingMembershipUuid();
         final var adoptingMembershipMemberNumber = resource.getAdoptingMembershipMemberNumber();
         if (adoptingMembershipUuid != null && adoptingMembershipMemberNumber != null) {
-            throw new IllegalArgumentException(
+            throw new ValidationException(
                     // @formatter:off
-                resource.getTransactionType() == TRANSFER
+                resource.getTransactionType() == HsOfficeCoopAssetsTransactionTypeResource.TRANSFER
-                    ? "[400] either adoptingMembership.uuid or adoptingMembership.memberNumber can be given, not both"
+                    ? "either adoptingMembership.uuid or adoptingMembership.memberNumber can be given, not both"
-                    : "[400] adoptingMembership.uuid and adoptingMembership.memberNumber must not be given for transactionType="
+                    : "adoptingMembership.uuid and adoptingMembership.memberNumber must not be given for transactionType="
                             + resource.getTransactionType());
                 // @formatter:on
         }
@@ -232,13 +293,9 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
                     + "' not found or not accessible");
         }
 
-        if (resource.getTransactionType() == TRANSFER) {
         throw new ValidationException(
                 "either adoptingMembership.uuid or adoptingMembership.memberNumber must be given for transactionType="
-                            + TRANSFER);
+                        + HsOfficeCoopAssetsTransactionTypeResource.TRANSFER);
-        }
-
-        return null;
     }
 
     private HsOfficeCoopAssetsTransactionEntity createAdoptingAssetTx(

src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionEntity.java

@@ -98,21 +98,21 @@ public class HsOfficeCoopAssetsTransactionEntity implements Stringifyable, BaseE
     private String comment;
 
     // Optionally, the UUID of the corresponding transaction for a reversal transaction.
-    @OneToOne(cascade = CascadeType.PERSIST) // TODO.impl: can probably be removed after office data migration
+    @OneToOne
     @JoinColumn(name = "revertedassettxuuid")
     private HsOfficeCoopAssetsTransactionEntity revertedAssetTx;
 
     // and the other way around
-    @OneToOne(mappedBy = "revertedAssetTx")
+    @OneToOne(mappedBy = "revertedAssetTx", cascade = CascadeType.PERSIST)
     private HsOfficeCoopAssetsTransactionEntity reversalAssetTx;
 
     // Optionally, the UUID of the corresponding transaction for a transfer transaction.
-    @OneToOne(cascade = CascadeType.PERSIST) // TODO.impl: can probably be removed after office data migration
+    @OneToOne(cascade = CascadeType.PERSIST)
     @JoinColumn(name = "assetadoptiontxuuid")
     private HsOfficeCoopAssetsTransactionEntity adoptionAssetTx;
 
     // and the other way around
-    @OneToOne(mappedBy = "adoptionAssetTx")
+    @OneToOne(mappedBy = "adoptionAssetTx", cascade = CascadeType.PERSIST)
     private HsOfficeCoopAssetsTransactionEntity transferAssetTx;
 
     @Override

src/main/java/net/hostsharing/hsadminng/lambda/WithNonNull.java

@@ -0,0 +1,11 @@
+package net.hostsharing.hsadminng.lambda;
+
+import java.util.function.Consumer;
+
+public class WithNonNull {
+        public static <T> void withNonNull(final T target, final Consumer<T> code) {
+            if (target != null ) {
+                code.accept(target);
+            }
+    }
+}

src/main/resources/db/changelog/5-hs-office/512-coopassets/5120-hs-office-coopassets.sql

@@ -35,21 +35,41 @@ create table if not exists hs_office.coopassettx
 --changeset michael.hoennig:hs-office-coopassets-BUSINESS-RULES endDelimiter:--//
 -- ----------------------------------------------------------------------------
 
-alter table hs_office.coopassettx
+-- Not as CHECK constraints because those cannot be deferrable,
-    add constraint reversal_asset_tx_must_have_reverted_asset_tx
+-- but we need these constraints deferrable because the rows are linked to each other.
-        check (transactionType <> 'REVERSAL' or revertedAssetTxUuid is not null);
 
-alter table hs_office.coopassettx
+CREATE OR REPLACE FUNCTION validate_transaction_type()
-    add constraint non_reversal_asset_tx_must_not_have_reverted_asset_tx
+    RETURNS TRIGGER AS $$
-        check (transactionType = 'REVERSAL' or revertedAssetTxUuid is null or transactionType = 'REVERSAL');
+BEGIN
+    -- REVERSAL transactions must have revertedAssetTxUuid
+    IF NEW.transactionType = 'REVERSAL' AND NEW.revertedAssetTxUuid IS NULL THEN
+        RAISE EXCEPTION 'REVERSAL transactions must have revertedAssetTxUuid';
+    END IF;
 
-alter table hs_office.coopassettx
+    -- Non-REVERSAL transactions must not have revertedAssetTxUuid
-    add constraint transfer_asset_tx_must_have_adopted_asset_tx
+    IF NEW.transactionType != 'REVERSAL' AND NEW.revertedAssetTxUuid IS NOT NULL THEN
-        check (transactionType <> 'TRANSFER' or assetAdoptionTxUuid is not null);
+        RAISE EXCEPTION 'Non-REVERSAL transactions must not have revertedAssetTxUuid';
+    END IF;
+
+    -- TRANSFER transactions must have assetAdoptionTxUuid
+    IF NEW.transactionType = 'TRANSFER' AND NEW.assetAdoptionTxUuid IS NULL THEN
+        RAISE EXCEPTION 'TRANSFER transactions must have assetAdoptionTxUuid';
+    END IF;
+
+    -- Non-TRANSFER transactions must not have assetAdoptionTxUuid
+    IF NEW.transactionType != 'TRANSFER' AND NEW.assetAdoptionTxUuid IS NOT NULL THEN
+        RAISE EXCEPTION 'Non-TRANSFER transactions must not have assetAdoptionTxUuid';
+    END IF;
+
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Attach the trigger to the table
+CREATE TRIGGER enforce_transaction_constraints
+    AFTER INSERT OR UPDATE ON hs_office.coopassettx
+    FOR EACH ROW EXECUTE FUNCTION validate_transaction_type();
 
-alter table hs_office.coopassettx
-    add constraint non_transfer_asset_tx_must_not_have_adopted_asset_tx
-        check (transactionType = 'TRANSFER' or assetAdoptionTxUuid is null);
 --//
 
 -- ============================================================================

src/test/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionControllerRestTest.java

@@ -10,6 +10,7 @@ import net.hostsharing.hsadminng.persistence.EntityManagerWrapper;
 import net.hostsharing.hsadminng.rbac.test.JsonBuilder;
 import net.hostsharing.hsadminng.test.TestUuidGenerator;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.EnumSource;
 import org.junit.runner.RunWith;
@@ -24,12 +25,20 @@ import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
 
 import java.math.BigDecimal;
 import java.time.LocalDate;
+import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
 import java.util.function.Function;
 
+import static net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionType.ADOPTION;
+import static net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionType.DEPOSIT;
+import static net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionType.DISBURSAL;
+import static net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionType.REVERSAL;
+import static net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionType.TRANSFER;
 import static net.hostsharing.hsadminng.rbac.test.JsonBuilder.jsonObject;
 import static net.hostsharing.hsadminng.rbac.test.JsonMatcher.lenientlyEquals;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assumptions.assumeThat;
 import static org.hamcrest.Matchers.is;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
@@ -42,7 +51,13 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 @RunWith(SpringRunner.class)
 class HsOfficeCoopAssetsTransactionControllerRestTest {
 
-    private static final UUID UNAVAILABLE_MEMBERSHIP_UUID = TestUuidGenerator.use(0);
+    // If you need to run just a single test-case in this data-driven test-method, set SINGLE_TEST_CASE_EXECUTION to true!
+    // There is a test which fails if single test-case execution active to avoid merging this to master.
+    private static final boolean SINGLE_TEST_CASE_EXECUTION = false;
+
+    private static final int DYNAMIC_UUID_START_INDEX = 13;
+
+    private static final UUID UNAVAILABLE_UUID = TestUuidGenerator.use(0);
     private static final String UNAVAILABLE_MEMBER_NUMBER = "M-1234699";
 
     private static final UUID ORIGIN_MEMBERSHIP_UUID = TestUuidGenerator.use(1);
@@ -65,9 +80,11 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
             .memberNumberSuffix(suffixOf(AVAILABLE_TARGET_MEMBER_NUMBER))
             .build();
 
-    // the following refs might change if impl changes
+    // The following refs depend on the implementation of the respective implementation and might change if it changes.
-    private static final UUID NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID = TestUuidGenerator.ref(4);
+    // The same TestUuidGenerator.ref(#) does NOT mean the UUIDs refer to the same entity,
-    private static final UUID NEW_EXPLICITLY_CREATED_TRANSFER_ASSET_TX_UUID = TestUuidGenerator.ref(5);
+    // its rather coincidence because different test-cases have different execution paths in the production code.
+    private static final UUID NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID = TestUuidGenerator.ref(DYNAMIC_UUID_START_INDEX);
+    private static final UUID NEW_EXPLICITLY_CREATED_TRANSFER_ASSET_TX_UUID = TestUuidGenerator.ref(DYNAMIC_UUID_START_INDEX);
 
     private static final UUID SOME_EXISTING_LOSS_ASSET_TX_UUID = TestUuidGenerator.use(3);
     public final HsOfficeCoopAssetsTransactionEntity SOME_EXISTING_LOSS_ASSET_TX_ENTITY = HsOfficeCoopAssetsTransactionEntity.builder()
@@ -80,6 +97,402 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
             .valueDate(LocalDate.parse("2024-10-15"))
             .build();
 
+    private static final UUID SOME_EXISTING_TRANSFER_ASSET_TX_UUID = TestUuidGenerator.use(4);
+    public final HsOfficeCoopAssetsTransactionEntity SOME_EXISTING_TRANSFER_ASSET_TX_ENTITY = HsOfficeCoopAssetsTransactionEntity.builder()
+            .uuid(SOME_EXISTING_TRANSFER_ASSET_TX_UUID)
+            .membership(ORIGIN_TARGET_MEMBER_ENTITY)
+            .transactionType(HsOfficeCoopAssetsTransactionType.TRANSFER)
+            .assetValue(BigDecimal.valueOf(-256))
+            .reference("some transfer asset tx ref")
+            .comment("some transfer asset tx comment")
+            .valueDate(LocalDate.parse("2024-10-15"))
+            .build();
+
+    private static final UUID SOME_EXISTING_ADOPTION_ASSET_TX_UUID = TestUuidGenerator.use(5);
+    public final HsOfficeCoopAssetsTransactionEntity SOME_EXISTING_ADOPTION_ASSET_TX_ENTITY = HsOfficeCoopAssetsTransactionEntity.builder()
+            .uuid(SOME_EXISTING_ADOPTION_ASSET_TX_UUID)
+            .membership(ORIGIN_TARGET_MEMBER_ENTITY)
+            .transactionType(HsOfficeCoopAssetsTransactionType.TRANSFER)
+            .assetValue(SOME_EXISTING_TRANSFER_ASSET_TX_ENTITY.getAssetValue().negate())
+            .reference("some adoption asset tx ref")
+            .comment("some adoption asset tx comment")
+            .valueDate(LocalDate.parse("2024-10-15"))
+            .transferAssetTx(SOME_EXISTING_TRANSFER_ASSET_TX_ENTITY)
+            .build();
+    {
+        SOME_EXISTING_TRANSFER_ASSET_TX_ENTITY.setAdoptionAssetTx(SOME_EXISTING_ADOPTION_ASSET_TX_ENTITY);
+    }
+
+    private final static UUID SOME_REVERTED_DISBURSAL_ASSET_TX_UUID = TestUuidGenerator.use(7);
+    private final static UUID SOME_DISBURSAL_REVERSAL_ASSET_TX_UUID = TestUuidGenerator.use(8);
+    private final HsOfficeCoopAssetsTransactionEntity SOME_REVERTED_DISBURSAL_ASSET_TX_ENTITY = HsOfficeCoopAssetsTransactionEntity.builder()
+            .uuid(SOME_REVERTED_DISBURSAL_ASSET_TX_UUID)
+            .membership(ORIGIN_TARGET_MEMBER_ENTITY)
+            .transactionType(DISBURSAL)
+            .assetValue(BigDecimal.valueOf(-128.00))
+            .valueDate(LocalDate.parse("2024-10-15"))
+            .reference("some disbursal")
+            .comment("some disbursal to get reverted")
+            .reversalAssetTx(
+                    HsOfficeCoopAssetsTransactionEntity.builder()
+                            .uuid(SOME_DISBURSAL_REVERSAL_ASSET_TX_UUID)
+                            .membership(ORIGIN_TARGET_MEMBER_ENTITY)
+                            .transactionType(REVERSAL)
+                            .assetValue(BigDecimal.valueOf(128.00))
+                            .valueDate(LocalDate.parse("2024-10-20"))
+                            .reference("some reversal")
+                            .comment("some reversal of a disbursal asset tx")
+                            .build()
+            )
+            .build();
+    {
+        SOME_REVERTED_DISBURSAL_ASSET_TX_ENTITY.getReversalAssetTx().setRevertedAssetTx(SOME_REVERTED_DISBURSAL_ASSET_TX_ENTITY);
+    }
+
+    private final static UUID SOME_REVERTED_TRANSFER_ASSET_TX_UUID = TestUuidGenerator.use(9);
+    private final static UUID SOME_TRANSFER_REVERSAL_ASSET_TX_UUID = TestUuidGenerator.use(10);
+    private final static UUID SOME_REVERTED_ADOPTION_ASSET_TX_UUID = TestUuidGenerator.use(11);
+    private final static UUID SOME_ADOPTION_REVERSAL_ASSET_TX_UUID = TestUuidGenerator.use(12);
+    final HsOfficeCoopAssetsTransactionEntity SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY = HsOfficeCoopAssetsTransactionEntity.builder()
+            .uuid(SOME_REVERTED_TRANSFER_ASSET_TX_UUID)
+            .membership(ORIGIN_TARGET_MEMBER_ENTITY)
+            .transactionType(TRANSFER)
+            .assetValue(BigDecimal.valueOf(-1024))
+            .valueDate(LocalDate.parse("2024-11-10"))
+            .reference("some transfer")
+            .comment("some transfer to get reverted")
+            .adoptionAssetTx(
+                    HsOfficeCoopAssetsTransactionEntity.builder()
+                            .uuid(SOME_REVERTED_ADOPTION_ASSET_TX_UUID)
+                            .membership(AVAILABLE_MEMBER_ENTITY)
+                            .transactionType(ADOPTION)
+                            .assetValue(BigDecimal.valueOf(1024))
+                            .valueDate(LocalDate.parse("2024-11-10"))
+                            .reference("related adoption")
+                            .comment("some reversal of a transfer asset tx")
+                            .reversalAssetTx(
+                                    HsOfficeCoopAssetsTransactionEntity.builder()
+                                            .uuid(SOME_ADOPTION_REVERSAL_ASSET_TX_UUID)
+                                            .membership(AVAILABLE_MEMBER_ENTITY)
+                                            .transactionType(REVERSAL)
+                                            .assetValue(BigDecimal.valueOf(1024))
+                                            .valueDate(LocalDate.parse("2024-11-11"))
+                                            .reference("some reversal")
+                                            .comment("some adoption asset tx reversal")
+                                            .build()
+                            )
+                            .build()
+            )
+            .reversalAssetTx(
+                    HsOfficeCoopAssetsTransactionEntity.builder()
+                            .uuid(SOME_TRANSFER_REVERSAL_ASSET_TX_UUID)
+                            .membership(ORIGIN_TARGET_MEMBER_ENTITY)
+                            .transactionType(REVERSAL)
+                            .assetValue(BigDecimal.valueOf(1024))
+                            .valueDate(LocalDate.parse("2024-11-11"))
+                            .reference("some transfer")
+                            .comment("some transfer asset tx reversal")
+                            .build()
+            )
+            .build();
+    {
+        SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getAdoptionAssetTx()
+                .setTransferAssetTx(SOME_REVERTED_DISBURSAL_ASSET_TX_ENTITY);
+        SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getReversalAssetTx()
+                .setRevertedAssetTx(SOME_REVERTED_DISBURSAL_ASSET_TX_ENTITY);
+        SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getAdoptionAssetTx().getReversalAssetTx()
+                .setRevertedAssetTx(SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getAdoptionAssetTx());
+    }
+
+    private static final String EXPECTED_RESULT_FROM_GET_SINGLE = """
+            {
+                 "uuid": "99999999-9999-9999-9999-999999999999",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "TRANSFER",
+                 "assetValue": -1024,
+                 "valueDate": "2024-11-10",
+                 "reference": "some transfer",
+                 "comment": "some transfer to get reverted",
+                 "adoptionAssetTx": {
+                   "uuid": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
+                   "membership.uuid": "22222222-2222-2222-2222-222222222222",
+                   "membership.memberNumber": "M-1234500",
+                   "transactionType": "ADOPTION",
+                   "assetValue": 1024,
+                   "valueDate": "2024-11-10",
+                   "reference": "related adoption",
+                   "comment": "some reversal of a transfer asset tx",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": "99999999-9999-9999-9999-999999999999",
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": "cccccccc-cccc-cccc-cccc-cccccccccccc"
+                }
+            }
+            """;
+
+
+    private static final String EXPECTED_RESULT_FROM_GET_LIST = """
+            [
+               {
+                 "uuid": "33333333-3333-3333-3333-333333333333",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "LOSS",
+                 "assetValue": -64,
+                 "valueDate": "2024-10-15",
+                 "reference": "some loss asset tx ref",
+                 "comment": "some loss asset tx comment",
+                 "adoptionAssetTx": null,
+                 "transferAssetTx": null,
+                 "revertedAssetTx": null,
+                 "reversalAssetTx": null
+               },
+               {
+                 "uuid": "44444444-4444-4444-4444-444444444444",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "TRANSFER",
+                 "assetValue": -256,
+                 "valueDate": "2024-10-15",
+                 "reference": "some transfer asset tx ref",
+                 "comment": "some transfer asset tx comment",
+                 "adoptionAssetTx": {
+                   "uuid": "55555555-5555-5555-5555-555555555555",
+                   "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                   "membership.memberNumber": "M-1111100",
+                   "transactionType": "TRANSFER",
+                   "assetValue": 256,
+                   "valueDate": "2024-10-15",
+                   "reference": "some adoption asset tx ref",
+                   "comment": "some adoption asset tx comment",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": "44444444-4444-4444-4444-444444444444",
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": null
+                 },
+                 "transferAssetTx": null,
+                 "revertedAssetTx": null,
+                 "reversalAssetTx": null
+               },
+               {
+                 "uuid": "55555555-5555-5555-5555-555555555555",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "TRANSFER",
+                 "assetValue": 256,
+                 "valueDate": "2024-10-15",
+                 "reference": "some adoption asset tx ref",
+                 "comment": "some adoption asset tx comment",
+                 "adoptionAssetTx": null,
+                 "transferAssetTx": {
+                   "uuid": "44444444-4444-4444-4444-444444444444",
+                   "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                   "membership.memberNumber": "M-1111100",
+                   "transactionType": "TRANSFER",
+                   "assetValue": -256,
+                   "valueDate": "2024-10-15",
+                   "reference": "some transfer asset tx ref",
+                   "comment": "some transfer asset tx comment",
+                   "adoptionAssetTx.uuid": "55555555-5555-5555-5555-555555555555",
+                   "transferAssetTx.uuid": null,
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": null
+                 },
+                 "revertedAssetTx": null,
+                 "reversalAssetTx": null
+               },
+               {
+                 "uuid": "77777777-7777-7777-7777-777777777777",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "DISBURSAL",
+                 "assetValue": -128.0,
+                 "valueDate": "2024-10-15",
+                 "reference": "some disbursal",
+                 "comment": "some disbursal to get reverted",
+                 "adoptionAssetTx": null,
+                 "transferAssetTx": null,
+                 "revertedAssetTx": null,
+                 "reversalAssetTx": {
+                   "uuid": "88888888-8888-8888-8888-888888888888",
+                   "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                   "membership.memberNumber": "M-1111100",
+                   "transactionType": "REVERSAL",
+                   "assetValue": 128.0,
+                   "valueDate": "2024-10-20",
+                   "reference": "some reversal",
+                   "comment": "some reversal of a disbursal asset tx",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": null,
+                   "revertedAssetTx.uuid": "77777777-7777-7777-7777-777777777777",
+                   "reversalAssetTx.uuid": null
+                 }
+               },
+               {
+                 "uuid": "88888888-8888-8888-8888-888888888888",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "REVERSAL",
+                 "assetValue": 128.0,
+                 "valueDate": "2024-10-20",
+                 "reference": "some reversal",
+                 "comment": "some reversal of a disbursal asset tx",
+                 "adoptionAssetTx": null,
+                 "transferAssetTx": null,
+                 "revertedAssetTx": {
+                   "uuid": "77777777-7777-7777-7777-777777777777",
+                   "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                   "membership.memberNumber": "M-1111100",
+                   "transactionType": "DISBURSAL",
+                   "assetValue": -128.0,
+                   "valueDate": "2024-10-15",
+                   "reference": "some disbursal",
+                   "comment": "some disbursal to get reverted",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": null,
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": "88888888-8888-8888-8888-888888888888"
+                 },
+                 "reversalAssetTx": null
+               },
+               {
+                 "uuid": "99999999-9999-9999-9999-999999999999",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "TRANSFER",
+                 "assetValue": -1024,
+                 "valueDate": "2024-11-10",
+                 "reference": "some transfer",
+                 "comment": "some transfer to get reverted",
+                 "adoptionAssetTx": {
+                   "uuid": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
+                   "membership.uuid": "22222222-2222-2222-2222-222222222222",
+                   "membership.memberNumber": "M-1234500",
+                   "transactionType": "ADOPTION",
+                   "assetValue": 1024,
+                   "valueDate": "2024-11-10",
+                   "reference": "related adoption",
+                   "comment": "some reversal of a transfer asset tx",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": "99999999-9999-9999-9999-999999999999",
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": "cccccccc-cccc-cccc-cccc-cccccccccccc"
+                 },
+                 "transferAssetTx": null,
+                 "revertedAssetTx": null,
+                 "reversalAssetTx": {
+                   "uuid": "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",
+                   "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                   "membership.memberNumber": "M-1111100",
+                   "transactionType": "REVERSAL",
+                   "assetValue": 1024,
+                   "valueDate": "2024-11-11",
+                   "reference": "some transfer",
+                   "comment": "some transfer asset tx reversal",
+                   "adoptionAssetTx.uuid": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
+                   "transferAssetTx.uuid": null,
+                   "revertedAssetTx.uuid": "99999999-9999-9999-9999-999999999999",
+                   "reversalAssetTx.uuid": null
+                 }
+               },
+               {
+                 "uuid": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
+                 "membership.uuid": "22222222-2222-2222-2222-222222222222",
+                 "membership.memberNumber": "M-1234500",
+                 "transactionType": "ADOPTION",
+                 "assetValue": 1024,
+                 "valueDate": "2024-11-10",
+                 "reference": "related adoption",
+                 "comment": "some reversal of a transfer asset tx",
+                 "adoptionAssetTx": null,
+                 "transferAssetTx": {
+                   "uuid": "77777777-7777-7777-7777-777777777777",
+                   "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                   "membership.memberNumber": "M-1111100",
+                   "transactionType": "DISBURSAL",
+                   "assetValue": -128.0,
+                   "valueDate": "2024-10-15",
+                   "reference": "some disbursal",
+                   "comment": "some disbursal to get reverted",
+                   "adoptionAssetTx.uuid": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
+                   "transferAssetTx.uuid": null,
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": "88888888-8888-8888-8888-888888888888"
+                 },
+                 "revertedAssetTx": null,
+                 "reversalAssetTx": {
+                   "uuid": "cccccccc-cccc-cccc-cccc-cccccccccccc",
+                   "membership.uuid": "22222222-2222-2222-2222-222222222222",
+                   "membership.memberNumber": "M-1234500",
+                   "transactionType": "REVERSAL",
+                   "assetValue": 1024,
+                   "valueDate": "2024-11-11",
+                   "reference": "some reversal",
+                   "comment": "some adoption asset tx reversal",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": "77777777-7777-7777-7777-777777777777",
+                   "revertedAssetTx.uuid": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
+                   "reversalAssetTx.uuid": null
+                 }
+               },
+               {
+                 "uuid": "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",
+                 "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                 "membership.memberNumber": "M-1111100",
+                 "transactionType": "REVERSAL",
+                 "assetValue": 1024,
+                 "valueDate": "2024-11-11",
+                 "reference": "some transfer",
+                 "comment": "some transfer asset tx reversal",
+                 "adoptionAssetTx": null,
+                 "transferAssetTx": null,
+                 "revertedAssetTx": {
+                   "uuid": "77777777-7777-7777-7777-777777777777",
+                   "membership.uuid": "11111111-1111-1111-1111-111111111111",
+                   "membership.memberNumber": "M-1111100",
+                   "transactionType": "DISBURSAL",
+                   "assetValue": -128.0,
+                   "valueDate": "2024-10-15",
+                   "reference": "some disbursal",
+                   "comment": "some disbursal to get reverted",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": null,
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa"
+                 },
+                 "reversalAssetTx": null
+               },
+               {
+                 "uuid": "cccccccc-cccc-cccc-cccc-cccccccccccc",
+                 "membership.uuid": "22222222-2222-2222-2222-222222222222",
+                 "membership.memberNumber": "M-1234500",
+                 "transactionType": "REVERSAL",
+                 "assetValue": 1024,
+                 "valueDate": "2024-11-11",
+                 "reference": "some reversal",
+                 "comment": "some adoption asset tx reversal",
+                 "adoptionAssetTx": null,
+                 "transferAssetTx": null,
+                 "revertedAssetTx": {
+                   "uuid": "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
+                   "membership.uuid": "22222222-2222-2222-2222-222222222222",
+                   "membership.memberNumber": "M-1234500",
+                   "transactionType": "ADOPTION",
+                   "assetValue": 1024,
+                   "valueDate": "2024-11-10",
+                   "reference": "related adoption",
+                   "comment": "some reversal of a transfer asset tx",
+                   "adoptionAssetTx.uuid": null,
+                   "transferAssetTx.uuid": "77777777-7777-7777-7777-777777777777",
+                   "revertedAssetTx.uuid": null,
+                   "reversalAssetTx.uuid": "cccccccc-cccc-cccc-cccc-cccccccccccc"
+                 },
+                 "reversalAssetTx": null
+               }
+            ]
+            """;
+
     @Autowired
     MockMvc mockMvc;
 
@@ -117,6 +530,44 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
                 requestBody -> requestBody.without("membership.uuid"),
                 "[membershipUuid must not be null but is \"null\"]"), // TODO.impl: should be membership.uuid, Spring validation-problem?
 
+        MEMBERSHIP_UUID_NOT_FOUND_OR_NOT_ACCESSIBLE(
+                requestBody -> requestBody.with("membership.uuid", UNAVAILABLE_UUID),
+                "membership.uuid " + UNAVAILABLE_UUID + " not found"),
+
+        MEMBERSHIP_UUID_AND_MEMBER_NUMBER_MUST_NOT_BE_GIVEN_BOTH(
+                requestBody -> requestBody
+                        .with("transactionType", TRANSFER.name())
+                        .with("assetValue", "-128.00")
+                        .with("adoptingMembership.uuid", UNAVAILABLE_UUID)
+                        .with("adoptingMembership.memberNumber", UNAVAILABLE_MEMBER_NUMBER),
+                "either adoptingMembership.uuid or adoptingMembership.memberNumber can be given, not both"),
+
+        MEMBERSHIP_UUID_OR_MEMBER_NUMBER_MUST_BE_GIVEN(
+                requestBody -> requestBody
+                        .with("transactionType", TRANSFER)
+                        .with("assetValue", "-128.00"),
+                "either adoptingMembership.uuid or adoptingMembership.memberNumber must be given for transactionType=TRANSFER"),
+
+        REVERSAL_ASSET_TRANSACTION_REQUIRES_REVERTED_ASSET_TX_UUID(
+                requestBody -> requestBody
+                            .with("transactionType", REVERSAL)
+                            .with("assetValue", "-128.00"),
+                "REVERSAL asset transaction requires revertedAssetTx.uuid"),
+
+        REVERSAL_ASSET_TRANSACTION_REQUIRES_AVAILABLE_REVERTED_ASSET_TX_UUID(
+                requestBody -> requestBody
+                        .with("transactionType", REVERSAL)
+                        .with("assetValue", "-128.00")
+                        .with("revertedAssetTx.uuid", UNAVAILABLE_UUID),
+                "revertedAssetTx.uuid " + UNAVAILABLE_UUID + " not found"),
+
+        REVERSAL_ASSET_TRANSACTION_MUST_NEGATE_VALUE_OF_REVERTED_ASSET_TX(
+                requestBody -> requestBody
+                        .with("transactionType", REVERSAL)
+                        .with("assetValue", "128.00")
+                        .with("revertedAssetTx.uuid", SOME_EXISTING_LOSS_ASSET_TX_UUID),
+                "given assetValue=128.00 but must be negative value from reverted asset tx: -64"),
+
         TRANSACTION_TYPE_MISSING(
                 requestBody -> requestBody.without("transactionType"),
                 "[transactionType must not be null but is \"null\"]"),
@@ -127,35 +578,40 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
 
         ASSETS_VALUE_FOR_DEPOSIT_MUST_BE_POSITIVE(
                 requestBody -> requestBody
-                        .with("transactionType", "DEPOSIT")
+                        .with("transactionType", DEPOSIT)
                         .with("assetValue", -64.00),
                 "[for DEPOSIT, assetValue must be positive but is \"-64.00\"]"),
 
         ASSETS_VALUE_FOR_DISBURSAL_MUST_BE_NEGATIVE(
                 requestBody -> requestBody
-                        .with("transactionType", "DISBURSAL")
+                        .with("transactionType", DISBURSAL)
                         .with("assetValue", 64.00),
                 "[for DISBURSAL, assetValue must be negative but is \"64.00\"]"),
 
-        //TODO: other transaction types
+        ADOPTING_MEMBERSHIP_MUST_NOT_BE_THE_SAME(
+                requestBody -> requestBody
+                        .with("transactionType", TRANSFER)
+                        .with("assetValue", -64.00)
+                        .with("adoptingMembership.uuid", ORIGIN_MEMBERSHIP_UUID),
+                "transferring and adopting membership must be different, but both are M-1111100"),
 
         ADOPTING_MEMBERSHIP_NUMBER_FOR_TRANSFER_MUST_BE_GIVEN_AND_AVAILABLE(
                 requestBody -> requestBody
-                        .with("transactionType", "TRANSFER")
+                        .with("transactionType", TRANSFER)
                         .with("assetValue", -64.00)
                         .with("adoptingMembership.memberNumber", UNAVAILABLE_MEMBER_NUMBER),
                 "adoptingMembership.memberNumber='M-1234699' not found or not accessible"),
 
         ADOPTING_MEMBERSHIP_UUID_FOR_TRANSFER_MUST_BE_GIVEN_AND_AVAILABLE(
                 requestBody -> requestBody
-                        .with("transactionType", "TRANSFER")
+                        .with("transactionType", TRANSFER)
                         .with("assetValue", -64.00)
-                        .with("adoptingMembership.uuid", UNAVAILABLE_MEMBERSHIP_UUID.toString()),
+                        .with("adoptingMembership.uuid", UNAVAILABLE_UUID),
-                "adoptingMembership.uuid='" + UNAVAILABLE_MEMBERSHIP_UUID + "' not found or not accessible"),
+                "adoptingMembership.uuid='" + UNAVAILABLE_UUID + "' not found or not accessible"),
 
         ASSETS_VALUE_MUST_NOT_BE_NULL(
                 requestBody -> requestBody
-                        .with("transactionType", "REVERSAL")
+                        .with("transactionType", REVERSAL)
                         .with("assetValue", 0.00),
                 "[assetValue must not be 0 but is \"0.00\"]"),
 
@@ -190,8 +646,10 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
     @EnumSource(BadRequestTestCases.class)
     void respondWithBadRequest(final BadRequestTestCases testCase) throws Exception {
         // HOWTO: run just a single test-case in a data-driven test-method
-        // org.assertj.core.api.Assumptions.assumeThat(
+        //  - set SINGLE_TEST_CASE_EXECUTION to true - see above
-        //      testCase == ADOPTING_MEMBERSHIP_NUMBER_FOR_TRANSFER_MUST_BE_GIVEN_AND_AVAILABLE).isTrue();
+        //  - select the test case enum value you want to run
+        assumeThat(!SINGLE_TEST_CASE_EXECUTION ||
+                testCase == BadRequestTestCases.ADOPTING_MEMBERSHIP_MUST_NOT_BE_THE_SAME).isTrue();
 
         // when
         mockMvc.perform(MockMvcRequestBuilders
@@ -202,9 +660,9 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
                         .accept(MediaType.APPLICATION_JSON))
 
                 // then
-                .andExpect(jsonPath("message", is("ERROR: [400] " + testCase.expectedErrorMessage)))
                 .andExpect(jsonPath("statusCode", is(400)))
                 .andExpect(jsonPath("statusPhrase", is("Bad Request")))
+                .andExpect(jsonPath("message", is("ERROR: [400] " + testCase.expectedErrorMessage)))
                 .andExpect(status().is4xxClientError());
     }
 
@@ -212,28 +670,38 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
 
         REVERTING_SIMPLE_ASSET_TRANSACTION(
                 requestBody -> requestBody
-                        .with("transactionType", "REVERSAL")
+                        .with("transactionType", REVERSAL)
                         .with("assetValue", "64.00")
                         .with("valueDate", "2024-10-15")
-                        .with("reference", "reversal ref")
+                        .with("reference", "reversal of loss ref")
-                        .with("comment", "reversal comment")
+                        .with("comment", "reversal of loss asset tx comment")
-                        .with("revertedAssetTx.uuid", SOME_EXISTING_LOSS_ASSET_TX_UUID.toString()),
+                        .with("revertedAssetTx.uuid", SOME_EXISTING_LOSS_ASSET_TX_UUID),
-                Expected.REVERT_RESPONSE),
+                Expected.REVERT_LOSS_RESPONSE),
 
         TRANSFER_TO_GIVEN_AVAILABLE_MEMBERSHIP_NUMBER(
                 requestBody -> requestBody
-                        .with("transactionType", "TRANSFER")
+                        .with("transactionType", TRANSFER)
                         .with("assetValue", -64.00)
                         .with("adoptingMembership.memberNumber", AVAILABLE_TARGET_MEMBER_NUMBER),
                 Expected.TRANSFER_RESPONSE),
 
         TRANSFER_TO_GIVEN_AVAILABLE_MEMBERSHIP_UUID(
                 requestBody -> requestBody
-                        .with("transactionType", "TRANSFER")
+                        .with("transactionType", TRANSFER)
                         .with("assetValue", -64.00)
-                        .with("membership.uuid", ORIGIN_MEMBERSHIP_UUID.toString())
+                        .with("membership.uuid", ORIGIN_MEMBERSHIP_UUID)
-                        .with("adoptingMembership.uuid", AVAILABLE_TARGET_MEMBERSHIP_UUID.toString()),
+                        .with("adoptingMembership.uuid", AVAILABLE_TARGET_MEMBERSHIP_UUID),
-                Expected.TRANSFER_RESPONSE);
+                Expected.TRANSFER_RESPONSE),
+
+        REVERTING_TRANSFER_ASSET_TRANSACTION_IMPLICITLY_REVERTS_ADOPTING_ASSET_TRANSACTION(
+                requestBody -> requestBody
+                        .with("transactionType", REVERSAL)
+                        .with("assetValue", "256.00")
+                        .with("valueDate", "2024-10-15")
+                        .with("reference", "reversal of transfer ref")
+                        .with("comment", "reversal of transfer asset tx comment")
+                        .with("revertedAssetTx.uuid", SOME_EXISTING_TRANSFER_ASSET_TX_UUID),
+                Expected.REVERT_TRANSFER_RESPONSE);
 
         private final Function<JsonBuilder, JsonBuilder> givenBodyTransformation;
         private final String expectedResponseBody;
@@ -251,7 +719,7 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
 
         private static class Expected {
 
-            public static final String REVERT_RESPONSE = """
+            public static final String REVERT_LOSS_RESPONSE = """
                     {
                          "uuid": "%{NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID}",
                          "membership.uuid": "%{ORIGIN_MEMBERSHIP_UUID}",
@@ -259,9 +727,10 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
                          "transactionType": "REVERSAL",
                          "assetValue": 64.00,
                          "valueDate": "2024-10-15",
-                         "reference": "reversal ref",
+                         "reference": "reversal of loss ref",
-                         "comment": "reversal comment",
+                         "comment": "reversal of loss asset tx comment",
                          "adoptionAssetTx": null,
+                         "reversalAssetTx": null,
                          "transferAssetTx": null,
                          "revertedAssetTx": {
                            "uuid": "%{SOME_EXISTING_LOSS_ASSET_TX_UUID}",
@@ -279,7 +748,9 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
                          }
                     }
                     """
-                    .replace("%{NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID}", NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID.toString())
+                    .replace(
+                            "%{NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID}",
+                            NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID.toString())
                     .replace("%{ORIGIN_MEMBERSHIP_UUID}", ORIGIN_MEMBERSHIP_UUID.toString())
                     .replace("%{ORIGIN_MEMBER_NUMBER}", ORIGIN_MEMBER_NUMBER)
                     .replace("%{SOME_EXISTING_LOSS_ASSET_TX_UUID}", SOME_EXISTING_LOSS_ASSET_TX_UUID.toString());
@@ -303,20 +774,57 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
                         "reversalAssetTx": null
                     }
                     """
-                    .replace("%{NEW_EXPLICITLY_CREATED_TRANSFER_ASSET_TX_UUID}", NEW_EXPLICITLY_CREATED_TRANSFER_ASSET_TX_UUID.toString())
+                    .replace(
+                            "%{NEW_EXPLICITLY_CREATED_TRANSFER_ASSET_TX_UUID}",
+                            NEW_EXPLICITLY_CREATED_TRANSFER_ASSET_TX_UUID.toString())
                     .replace("%{ORIGIN_MEMBERSHIP_UUID}", ORIGIN_MEMBERSHIP_UUID.toString())
                     .replace("%{ORIGIN_MEMBER_NUMBER}", ORIGIN_MEMBER_NUMBER)
                     .replace("%{AVAILABLE_MEMBERSHIP_UUID}", AVAILABLE_TARGET_MEMBERSHIP_UUID.toString())
                     .replace("%{AVAILABLE_TARGET_MEMBER_NUMBER}", AVAILABLE_TARGET_MEMBER_NUMBER);
+
+            public static final String REVERT_TRANSFER_RESPONSE = """
+                    {
+                         "uuid": "%{NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID}",
+                         "membership.uuid": "%{ORIGIN_MEMBERSHIP_UUID}",
+                         "membership.memberNumber": "%{ORIGIN_MEMBER_NUMBER}",
+                         "transactionType": "REVERSAL",
+                         "assetValue": 256.00,
+                         "valueDate": "2024-10-15",
+                         "reference": "reversal of transfer ref",
+                         "comment": "reversal of transfer asset tx comment",
+                         "adoptionAssetTx": null,
+                         "transferAssetTx": null,
+                         "revertedAssetTx": {
+                           "uuid": "%{SOME_EXISTING_TRANSFER_ASSET_TX_UUID}",
+                           "membership.uuid": "%{ORIGIN_MEMBERSHIP_UUID}",
+                           "membership.memberNumber": "%{ORIGIN_MEMBER_NUMBER}",
+                           "transactionType": "TRANSFER",
+                           "assetValue": -256.00,
+                           "valueDate": "2024-10-15",
+                           "reference": "some transfer asset tx ref",
+                           "comment": "some transfer asset tx comment",
+                           "adoptionAssetTx.uuid": "%{SOME_EXISTING_ADOPTION_ASSET_TX_UUID}",
+                           "transferAssetTx.uuid": null,
+                           "revertedAssetTx.uuid": null,
+                           "reversalAssetTx.uuid": "%{NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID}"
+                         }
+                    }
+                    """
+                    .replace(
+                            "%{NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID}",
+                            NEW_EXPLICITLY_CREATED_REVERSAL_ASSET_TX_UUID.toString())
+                    .replace("%{ORIGIN_MEMBERSHIP_UUID}", ORIGIN_MEMBERSHIP_UUID.toString())
+                    .replace("%{ORIGIN_MEMBER_NUMBER}", ORIGIN_MEMBER_NUMBER)
+                    .replace("%{SOME_EXISTING_TRANSFER_ASSET_TX_UUID}", SOME_EXISTING_TRANSFER_ASSET_TX_UUID.toString())
+                    .replace("%{SOME_EXISTING_ADOPTION_ASSET_TX_UUID}", SOME_EXISTING_ADOPTION_ASSET_TX_UUID.toString());
         }
     }
 
     @ParameterizedTest
     @EnumSource(SuccessfullyCreatedTestCases.class)
     void respondWithSuccessfullyCreated(final SuccessfullyCreatedTestCases testCase) throws Exception {
-        // uncomment, if you need to run just a single test-case in this data-driven test-method
+        assumeThat(!SINGLE_TEST_CASE_EXECUTION ||
-        // org.assertj.core.api.Assumptions.assumeThat(
+                testCase == SuccessfullyCreatedTestCases.REVERTING_TRANSFER_ASSET_TRANSACTION_IMPLICITLY_REVERTS_ADOPTING_ASSET_TRANSACTION).isTrue();
-        //        testCase == ADOPTING_MEMBERSHIP_UUID_FOR_TRANSFER_MUST_BE_GIVEN_AND_AVAILABLE).isTrue();
 
         // when
         mockMvc.perform(MockMvcRequestBuilders
@@ -331,12 +839,77 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
                 .andExpect(jsonPath("$", lenientlyEquals(testCase.expectedResponseBody)));
     }
 
+    @Test
+    void getSingleGeneratesProperJsonForAvailableUuid() throws Exception {
+        // given
+        when(coopAssetsTransactionRepo.findByUuid(SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getUuid()))
+                .thenReturn(Optional.of(SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY));
+
+        // when
+        mockMvc.perform(MockMvcRequestBuilders
+                        .get("/api/hs/office/coopassetstransactions/" + SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getUuid())
+                        .header("current-subject", "superuser-alex@hostsharing.net")
+                        .contentType(MediaType.APPLICATION_JSON))
+
+                // then
+                .andExpect(status().is2xxSuccessful())
+                .andExpect(jsonPath("$", lenientlyEquals(EXPECTED_RESULT_FROM_GET_SINGLE)));
+    }
+
+    @Test
+    void getSingleGeneratesNotFoundForUnavailableUuid() throws Exception {
+        // given
+        when(coopAssetsTransactionRepo.findByUuid(UNAVAILABLE_UUID)).thenReturn(Optional.empty());
+
+        // when
+        mockMvc.perform(MockMvcRequestBuilders
+                        .get("/api/hs/office/coopassetstransactions/" + UNAVAILABLE_UUID)
+                        .header("current-subject", "superuser-alex@hostsharing.net")
+                        .contentType(MediaType.APPLICATION_JSON))
+
+                // then
+                .andExpect(status().isNotFound());
+    }
+
+    @Test
+    void getListGeneratesProperJson() throws Exception {
+        // given
+        when(coopAssetsTransactionRepo.findCoopAssetsTransactionByOptionalMembershipUuidAndDateRange(null, null, null))
+                .thenReturn(List.of(
+                        SOME_EXISTING_LOSS_ASSET_TX_ENTITY,
+                        SOME_EXISTING_TRANSFER_ASSET_TX_ENTITY,
+                        SOME_EXISTING_ADOPTION_ASSET_TX_ENTITY,
+                        SOME_REVERTED_DISBURSAL_ASSET_TX_ENTITY,
+                        SOME_REVERTED_DISBURSAL_ASSET_TX_ENTITY.getReversalAssetTx(),
+                        SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY,
+                        SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getAdoptionAssetTx(),
+                        SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getReversalAssetTx(),
+                        SOME_REVERTED_TRANSFER_ASSET_TX_ENTITY.getAdoptionAssetTx().getReversalAssetTx()
+                ));
+
+        // when
+        mockMvc.perform(MockMvcRequestBuilders
+                        .get("/api/hs/office/coopassetstransactions")
+                        .header("current-subject", "superuser-alex@hostsharing.net")
+                        .contentType(MediaType.APPLICATION_JSON))
+
+                // then
+                .andExpect(status().is2xxSuccessful())
+                .andExpect(jsonPath("$", lenientlyEquals(EXPECTED_RESULT_FROM_GET_LIST)));
+    }
+
+    @Test
+    void singleTestCaseExecutionMustBeDisabled() {
+        assertThat(SINGLE_TEST_CASE_EXECUTION).isFalse();
+    }
+
     @BeforeEach
     void initMocks() {
-        TestUuidGenerator.start(4);
+        TestUuidGenerator.start(DYNAMIC_UUID_START_INDEX);
 
         when(emw.find(eq(HsOfficeMembershipEntity.class), eq(ORIGIN_MEMBERSHIP_UUID))).thenReturn(ORIGIN_TARGET_MEMBER_ENTITY);
-        when(emw.find(eq(HsOfficeMembershipEntity.class), eq(AVAILABLE_TARGET_MEMBERSHIP_UUID))).thenReturn(AVAILABLE_MEMBER_ENTITY);
+        when(emw.find(eq(HsOfficeMembershipEntity.class), eq(AVAILABLE_TARGET_MEMBERSHIP_UUID))).thenReturn(
+                AVAILABLE_MEMBER_ENTITY);
 
         final var availableMemberNumber = Integer.valueOf(AVAILABLE_TARGET_MEMBER_NUMBER.substring("M-".length()));
         when(membershipRepo.findMembershipByMemberNumber(eq(availableMemberNumber))).thenReturn(AVAILABLE_MEMBER_ENTITY);
@@ -346,6 +919,10 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
 
         when(coopAssetsTransactionRepo.findByUuid(SOME_EXISTING_LOSS_ASSET_TX_UUID))
                 .thenReturn(Optional.of(SOME_EXISTING_LOSS_ASSET_TX_ENTITY));
+        when(coopAssetsTransactionRepo.findByUuid(SOME_EXISTING_TRANSFER_ASSET_TX_UUID))
+                .thenReturn(Optional.of(SOME_EXISTING_TRANSFER_ASSET_TX_ENTITY));
+        when(coopAssetsTransactionRepo.findByUuid(SOME_EXISTING_ADOPTION_ASSET_TX_UUID))
+                .thenReturn(Optional.of(SOME_EXISTING_ADOPTION_ASSET_TX_ENTITY));
         when(coopAssetsTransactionRepo.save(any(HsOfficeCoopAssetsTransactionEntity.class)))
                 .thenAnswer(invocation -> {
                             final var entity = (HsOfficeCoopAssetsTransactionEntity) invocation.getArgument(0);
@@ -358,10 +935,10 @@ class HsOfficeCoopAssetsTransactionControllerRestTest {
     }
 
     private int partnerNumberOf(final String memberNumber) {
-        return Integer.parseInt(memberNumber.substring("M-".length(), memberNumber.length()-2));
+        return Integer.parseInt(memberNumber.substring("M-".length(), memberNumber.length() - 2));
     }
 
     private String suffixOf(final String memberNumber) {
-        return memberNumber.substring("M-".length()+5);
+        return memberNumber.substring("M-".length() + 5);
     }
 }

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/HsOfficeScenarioTests.java

@@ -16,7 +16,8 @@ import net.hostsharing.hsadminng.hs.office.scenarios.membership.CancelMembership
 import net.hostsharing.hsadminng.hs.office.scenarios.membership.CreateMembership;
 import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets.CreateCoopAssetsDepositTransaction;
 import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets.CreateCoopAssetsDisbursalTransaction;
-import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets.CreateCoopAssetsRevertTransaction;
+import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets.CreateCoopAssetsRevertSimpleTransaction;
+import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets.CreateCoopAssetsRevertTransferTransaction;
 import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets.CreateCoopAssetsTransferTransaction;
 import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopshares.CreateCoopSharesCancellationTransaction;
 import net.hostsharing.hsadminng.hs.office.scenarios.membership.coopshares.CreateCoopSharesRevertTransaction;
@@ -30,7 +31,6 @@ import net.hostsharing.hsadminng.hs.office.scenarios.subscription.RemoveOperatio
 import net.hostsharing.hsadminng.hs.office.scenarios.subscription.SubscribeToMailinglist;
 import net.hostsharing.hsadminng.hs.office.scenarios.subscription.UnsubscribeFromMailinglist;
 import net.hostsharing.hsadminng.rbac.test.JpaAttempt;
-import net.hostsharing.hsadminng.test.IgnoreOnFailure;
 import net.hostsharing.hsadminng.test.IgnoreOnFailureExtension;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.MethodOrderer;
@@ -395,7 +395,7 @@ class HsOfficeScenarioTests extends ScenarioTest {
     @Order(4302)
     @Requires("Membership: M-3101000 - Test AG")
     void shouldRevertCoopAssetsSubscription() {
-        new CreateCoopAssetsRevertTransaction(this)
+        new CreateCoopAssetsRevertSimpleTransaction(this)
                 .given("memberNumber", "M-3101000")
                 .given("comment", "reverting some incorrect transaction")
                 .given("dateOfIncorrectTransaction", "2024-02-15")
@@ -419,13 +419,13 @@ class HsOfficeScenarioTests extends ScenarioTest {
     @Test
     @Order(4304)
     @Requires("Coop-Assets M-3101000 - Test AG - DEPOSIT Transaction")
-    @Produces("Coop-Assets M-3101000 - Test AG - TRANSFER Transaction")
+    @Produces(explicitly = "Coop-Assets M-3101000 - Test AG - TRANSFER Transaction", implicitly = "Membership M-4303000")
     void shouldTransferCoopAssets() {
         new CreateCoopAssetsTransferTransaction(this)
                 .given("transferringMemberNumber", "M-3101000")
                 .given("adoptingMemberNumber", "M-4303000")
                 .given("reference", "transfer 2024-12-31")
-                .given("valueToDisburse", 2 * 64)
+                .given("valueToTransfer", 2 * 64)
                 .given("comment", "transfer assets from M-3101000 to M-4303000")
                 .given("transactionDate", "2024-12-31")
                 .doRun();
@@ -433,11 +433,12 @@ class HsOfficeScenarioTests extends ScenarioTest {
 
     @Test
     @Order(4305)
-    @Requires("Coop-Assets M-3101000 - Test AG - TRANSFER Transaction")
+    @Requires("Membership M-4303000")
-    @IgnoreOnFailure("TODO.impl: reverting transfers is not implemented yet")
+    void shouldRevertCoopAssetsTransferIncludingRelatedAssetAdoption() {
-    void shouldRevertCoopAssetsTransfer() {
+        new CreateCoopAssetsRevertTransferTransaction(this)
-        new CreateCoopAssetsRevertTransaction(this)
+                .given("transferringMemberNumber", "M-3101000")
-                .given("memberNumber", "M-3101000")
+                .given("adoptingMemberNumber", "M-4303000")
+                .given("transferredValue", 2*64)
                 .given("comment", "reverting some incorrect transfer transaction")
                 .given("dateOfIncorrectTransaction", "2024-02-15")
                 .doRun();

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/JsonOptional.java

@@ -0,0 +1,44 @@
+package net.hostsharing.hsadminng.hs.office.scenarios;
+
+
+public final class JsonOptional<V> {
+
+    private final boolean jsonValueGiven;
+    private final V jsonValue;
+
+    private JsonOptional() {
+        this.jsonValueGiven = false;
+        this.jsonValue = null;
+    }
+
+    private JsonOptional(final V jsonValue) {
+        this.jsonValueGiven = true;
+        this.jsonValue = jsonValue;
+    }
+
+    public static <T> JsonOptional<T> ofValue(final T value) {
+        return new JsonOptional<>(value);
+    }
+
+    public static <T> JsonOptional<T> notGiven() {
+        return new JsonOptional<>();
+    }
+
+    public V given() {
+        if (!jsonValueGiven) {
+            throw new IllegalStateException("JSON value was not given");
+        }
+        return jsonValue;
+    }
+
+    public String givenAsString() {
+        if (jsonValue instanceof Double doubleValue) {
+            if (doubleValue % 1 == 0) {
+                return String.valueOf(doubleValue.intValue()); // avoid trailing ".0"
+            } else {
+                return doubleValue.toString();
+            }
+        }
+        return jsonValue == null ? null : jsonValue.toString();
+    }
+}

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/PathAssertion.java

@@ -19,7 +19,7 @@ public class PathAssertion {
     public Consumer<UseCase.HttpResponse> contains(final String resolvableValue) {
         return response -> {
             try {
-                response.path(path).map(this::asString).contains(ScenarioTest.resolve(resolvableValue, DROP_COMMENTS));
+                response.path(path).isEqualTo(ScenarioTest.resolve(resolvableValue, DROP_COMMENTS));
             } catch (final AssertionError e) {
                 // without this, the error message is often lacking important context
                 fail(e.getMessage() + " in `path(\"" + path +  "\").contains(\"" + resolvableValue + "\")`" );
@@ -37,15 +37,4 @@ public class PathAssertion {
             }
         };
     }
-
-    private String asString(final Object value) {
-        if (value instanceof Double doubleValue) {
-            if (doubleValue % 1 == 0) {
-                return String.valueOf(doubleValue.intValue()); // avoid trailing ".0"
-            } else {
-                return doubleValue.toString();
-            }
-        }
-        return value.toString();
-    }
 }

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/ScenarioTest.java

@@ -16,6 +16,7 @@ import org.springframework.boot.test.web.server.LocalServerPort;
 import org.testcontainers.shaded.org.apache.commons.lang3.ObjectUtils;
 
 import java.lang.reflect.Method;
+import java.math.BigDecimal;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -160,6 +161,10 @@ public abstract class ScenarioTest extends ContextBasedTest {
         properties.put(name, (value instanceof String string) ? resolveTyped(string) : value);
     }
 
+    static void removeProperty(final String propName) {
+        properties.remove(propName);
+    }
+
     static Map<String, Object> knowVariables() {
         final var map = new LinkedHashMap<String, Object>();
         ScenarioTest.aliases.forEach((key, value) -> map.put(key, value.uuid()));
@@ -172,8 +177,8 @@ public abstract class ScenarioTest extends ContextBasedTest {
         return resolved;
     }
 
-    public static Object resolveTyped(final String text) {
+    public static Object resolveTyped(final String resolvableText) {
-        final var resolved = resolve(text, DROP_COMMENTS);
+        final var resolved = resolve(resolvableText, DROP_COMMENTS);
         try {
             return UUID.fromString(resolved);
         } catch (final IllegalArgumentException e) {
@@ -182,4 +187,14 @@ public abstract class ScenarioTest extends ContextBasedTest {
         return resolved;
     }
 
+    public static <T> T resolveTyped(final String resolvableText, final Class<T> valueType) {
+        final var resolvedValue = resolve(resolvableText, DROP_COMMENTS);
+        if (valueType == BigDecimal.class) {
+            //noinspection unchecked
+            return (T) new BigDecimal(resolvedValue);
+        }
+        //noinspection unchecked
+        return (T) resolvedValue;
+    }
+
 }

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/TestReport.java

@@ -12,9 +12,12 @@ import java.io.IOException;
 import java.io.PrintWriter;
 import java.lang.reflect.Method;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Date;
 import java.util.Map;
+import java.util.regex.Pattern;
 
+import static java.lang.String.join;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class TestReport {
@@ -41,9 +44,12 @@ public class TestReport {
     }
 
     public void createTestLogMarkdownFile(final TestInfo testInfo) throws IOException {
-        final var testMethodName = testInfo.getTestMethod().map(Method::getName).orElseThrow();
+        final var testMethodName = testInfo.getTestMethod().map(Method::getName)
+                .map(TestReport::chopShouldPrefix)
+                .map(TestReport::splitMixedCaseIntoSeparateWords)
+                .orElseThrow();
         final var testMethodOrder = testInfo.getTestMethod().map(m -> m.getAnnotation(Order.class).value()).orElseThrow();
-        markdownReportFile = new File(BUILD_DOC_SCENARIOS, testMethodOrder + "-" + testMethodName + ".md");
+        markdownReportFile = new File(BUILD_DOC_SCENARIOS, testMethodOrder + ": " + testMethodName + ".md");
         markdownReport = new PrintWriter(new FileWriter(markdownReportFile));
         print("## Scenario #" + determineScenarioTitle(testInfo));
     }
@@ -119,6 +125,20 @@ public class TestReport {
         return result.toString();
     }
 
+    private static String chopShouldPrefix(final String text) {
+        return text.replaceAll("^should", "");
+    }
+
+    private static String splitMixedCaseIntoSeparateWords(final String text) {
+        final var WORD_FINDER = Pattern.compile("(([A-Z]?[a-z]+)|([A-Z]))");
+        final var matcher = WORD_FINDER.matcher(text);
+        final var words = new ArrayList<String>();
+        while (matcher.find()) {
+            words.add(matcher.group(0));
+        }
+        return join(" ", words);
+    }
+
     @SneakyThrows
     private String currentGitBranch() {
         try {

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/UseCase.java

@@ -9,13 +9,14 @@ import lombok.Getter;
 import lombok.SneakyThrows;
 import net.hostsharing.hsadminng.reflection.AnnotationFinder;
 import org.apache.commons.collections4.map.LinkedMap;
-import org.assertj.core.api.OptionalAssert;
+import org.assertj.core.api.AbstractStringAssert;
 import org.hibernate.AssertionFailure;
 import org.jetbrains.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 
+import jakarta.validation.constraints.NotNull;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
@@ -27,13 +28,13 @@ import java.util.Arrays;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.UUID;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
 import static java.net.URLEncoder.encode;
+import static java.util.stream.Collectors.joining;
 import static net.hostsharing.hsadminng.hs.office.scenarios.TemplateResolver.Resolver.DROP_COMMENTS;
 import static net.hostsharing.hsadminng.hs.office.scenarios.TemplateResolver.Resolver.KEEP_COMMENTS;
 import static net.hostsharing.hsadminng.test.DebuggerDetection.isDebuggerAttached;
@@ -95,6 +96,9 @@ public abstract class UseCase<T extends UseCase<?>> {
         );
         final var response = run();
         verify(response);
+
+        resetProperties();
+
         return response;
     }
 
@@ -109,7 +113,7 @@ public abstract class UseCase<T extends UseCase<?>> {
     }
 
     public final UseCase<T> given(final String propName, final Object propValue) {
-        givenProperties.put(propName, propValue);
+        givenProperties.put(propName, ScenarioTest.resolve(propValue == null ? null : propValue.toString(), KEEP_COMMENTS));
         ScenarioTest.putProperty(propName, propValue);
         return this;
     }
@@ -206,7 +210,8 @@ public abstract class UseCase<T extends UseCase<?>> {
         return new PathAssertion(path);
     }
 
-    protected void verify(
+    @SafeVarargs
+    protected final void verify(
             final String title,
             final Supplier<UseCase.HttpResponse> http,
             final Consumer<UseCase.HttpResponse>... assertions) {
@@ -236,12 +241,17 @@ public abstract class UseCase<T extends UseCase<?>> {
         String resolvePlaceholders() {
             return ScenarioTest.resolve(template, DROP_COMMENTS);
         }
+
     }
 
     private static Duration seconds(final int secondsIfNoDebuggerAttached) {
         return isDebuggerAttached() ? Duration.ofHours(1) : Duration.ofSeconds(secondsIfNoDebuggerAttached);
     }
 
+    private void resetProperties() {
+        givenProperties.forEach((propName, val) -> ScenarioTest.removeProperty(propName));
+    }
+
     public final class HttpResponse {
 
         @Getter
@@ -319,22 +329,25 @@ public abstract class UseCase<T extends UseCase<?>> {
         }
 
         @SneakyThrows
-        public String getFromBody(final String path) {
+        public <V> V getFromBody(final String path) {
-            return JsonPath.parse(response.body()).read(ScenarioTest.resolve(path, DROP_COMMENTS));
+            final var body = response.body();
+            final var resolvedPath = ScenarioTest.resolve(path, DROP_COMMENTS);
+            return JsonPath.parse(body).read(resolvedPath);
         }
 
+        @NotNull
         @SneakyThrows
-        public <T> Optional<T> getFromBodyAsOptional(final String path) {
+        public <V> JsonOptional<V> getFromBodyAsOptional(final String path) {
             try {
-                return Optional.ofNullable(JsonPath.parse(response.body()).read(ScenarioTest.resolve(path, DROP_COMMENTS)));
+                return JsonOptional.ofValue(getFromBody(path));
             } catch (final PathNotFoundException e) {
-                return null; // means the property did not exist at all, not that it was there with value null
+                return JsonOptional.notGiven();
             }
         }
 
         @SneakyThrows
-        public <T> OptionalAssert<T> path(final String path) {
+        public AbstractStringAssert<?> path(final String path) {
-            return assertThat(getFromBodyAsOptional(path));
+            return assertThat(getFromBodyAsOptional(path).givenAsString());
         }
 
         @SneakyThrows
@@ -396,4 +409,12 @@ public abstract class UseCase<T extends UseCase<?>> {
     private String title(String resultAlias) {
         return getClass().getSimpleName().replaceAll("([a-z])([A-Z]+)", "$1 $2") + " => " + resultAlias;
     }
+
+    @Override
+    public String toString() {
+        final var properties = givenProperties.entrySet().stream()
+                .map(e -> "\t" + e.getKey() + "=" + e.getValue())
+                .collect(joining("\n"));
+        return getClass().getSimpleName() + "(\n\t" + properties + "\n)";
+    }
 }

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/membership/coopassets/CreateCoopAssetsRevertSimpleTransaction.java

@@ -2,15 +2,15 @@ package net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets;
 
 import net.hostsharing.hsadminng.hs.office.scenarios.ScenarioTest;
 
-public class CreateCoopAssetsRevertTransaction extends CreateCoopAssetsTransaction {
+public class CreateCoopAssetsRevertSimpleTransaction extends CreateCoopAssetsTransaction {
 
-    public CreateCoopAssetsRevertTransaction(final ScenarioTest testSuite) {
+    public CreateCoopAssetsRevertSimpleTransaction(final ScenarioTest testSuite) {
         super(testSuite);
 
         requires("CoopAssets-Transaction with incorrect assetValue", alias ->
                 new CreateCoopAssetsDepositTransaction(testSuite)
                         .given("memberNumber", "%{memberNumber}")
-                        .given("reference", "sign %{dateOfIncorrectTransaction}") // same as relatedAssetTx
+                        .given("reference", "sign %{dateOfIncorrectTransaction}") // same text as relatedAssetTx
                         .given("assetValue", 10)
                         .given("comment", "coop-assets deposit transaction with wrong asset value")
                         .given("transactionDate", "%{dateOfIncorrectTransaction}")
@@ -21,7 +21,9 @@ public class CreateCoopAssetsRevertTransaction extends CreateCoopAssetsTransacti
     protected HttpResponse run() {
         given("transactionType", "REVERSAL");
         given("assetValue", -10);
+        given("reference", "sign %{dateOfIncorrectTransaction}"); // same text as relatedAssetTx
         given("revertedAssetTx", uuid("CoopAssets-Transaction with incorrect assetValue"));
+        given("transactionDate", "%{dateOfIncorrectTransaction}");
         return super.run();
     }
 }

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/membership/coopassets/CreateCoopAssetsRevertTransferTransaction.java

@@ -0,0 +1,59 @@
+package net.hostsharing.hsadminng.hs.office.scenarios.membership.coopassets;
+
+import io.restassured.http.ContentType;
+import net.hostsharing.hsadminng.hs.office.scenarios.ScenarioTest;
+import net.hostsharing.hsadminng.hs.office.scenarios.UseCase;
+import org.springframework.http.HttpStatus;
+
+import java.math.BigDecimal;
+
+import static net.hostsharing.hsadminng.hs.office.scenarios.ScenarioTest.resolveTyped;
+
+public class CreateCoopAssetsRevertTransferTransaction extends CreateCoopAssetsTransaction {
+
+    public CreateCoopAssetsRevertTransferTransaction(final ScenarioTest testSuite) {
+        super(testSuite);
+
+        requires("Accidental CoopAssets-TRANSFER-Transaction", alias ->
+                new CreateCoopAssetsTransferTransaction(testSuite)
+                        .given("reference", "transfer %{dateOfIncorrectTransaction}")
+                        .given("valueToTransfer", "%{transferredValue}")
+                        .given("comment", "accidental transfer of assets from %{transferringMemberNumber} to %{adoptingMemberNumber}")
+                        .given("transactionDate", "%{dateOfIncorrectTransaction}")
+        );
+    }
+
+    @Override
+    protected HttpResponse run() {
+        given("transactionType", "REVERSAL");
+        given("assetValue", "%{transferredValue}");
+        given("reference", "sign %{dateOfIncorrectTransaction}"); // same text as relatedAssetTx
+        given("revertedAssetTx", uuid("Accidental CoopAssets-TRANSFER-Transaction"));
+        given("transactionDate", "%{dateOfIncorrectTransaction}");
+        return super.run();
+    }
+
+    @Override
+    protected void verify(final UseCase<CreateCoopAssetsTransaction>.HttpResponse response) {
+        super.verify(response);
+
+        final var revertedAssetTxUuid = response.getFromBody("revertedAssetTx.uuid");
+        given("negativeAssetValue", resolveTyped("%{transferredValue}", BigDecimal.class).negate());
+
+        verify("Verify Reverted Coop-Assets TRANSFER-Transaction",
+                () -> httpGet("/api/hs/office/coopassetstransactions/" + revertedAssetTxUuid)
+                        .expecting(HttpStatus.OK).expecting(ContentType.JSON),
+                path("assetValue").contains("%{negativeAssetValue}"),
+                path("comment").contains("%{comment}"),
+                path("valueDate").contains("%{transactionDate}")
+        );
+
+        final var adoptionAssetTxUuid = response.getFromBody("revertedAssetTx.['adoptionAssetTx.uuid']");
+
+        verify("Verify Related Coop-Assets ADOPTION-Transaction Also Got Reverted",
+                () -> httpGet("/api/hs/office/coopassetstransactions/" + adoptionAssetTxUuid)
+                        .expecting(HttpStatus.OK).expecting(ContentType.JSON),
+                path("reversalAssetTx.['transferAssetTx.uuid']").contains(revertedAssetTxUuid.toString())
+        );
+    }
+}

src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/membership/coopassets/CreateCoopAssetsTransferTransaction.java

@@ -20,7 +20,7 @@ public class CreateCoopAssetsTransferTransaction extends CreateCoopAssetsTransac
         );
 
         requires("Membership: New AG", alias -> new CreateMembership(testSuite)
-                .given("partnerNumber", toPartnerNumber("%{adoptingMemberNumber}"))
+                .given("memberNumber", toPartnerNumber("%{adoptingMemberNumber}"))
                 .given("partnerName", "New AG")
                 .given("validFrom", "2024-11-15")
                 .given("newStatus", "ACTIVE")
@@ -34,8 +34,7 @@ public class CreateCoopAssetsTransferTransaction extends CreateCoopAssetsTransac
 
         given("memberNumber", "%{transferringMemberNumber}");
         given("transactionType", "TRANSFER");
-        given("assetValue", "-%{valueToDisburse}");
+        given("assetValue", "-%{valueToTransfer}");
-        given("assetValue", "-%{valueToDisburse}");
         return super.run();
     }
 

src/test/java/net/hostsharing/hsadminng/lambda/WithNonNullUnitTest.java

@@ -0,0 +1,30 @@
+package net.hostsharing.hsadminng.lambda;
+
+import org.junit.jupiter.api.Test;
+
+import static net.hostsharing.hsadminng.lambda.WithNonNull.withNonNull;
+import static org.assertj.core.api.Assertions.assertThat;
+
+class WithNonNullUnitTest {
+
+    Boolean didRun = null;
+
+    @Test
+    void withNonNullRunsBodyIfNotNull() {
+        didRun = false;
+        withNonNull("test", nonNullValue -> {
+            assertThat(nonNullValue).isEqualTo("test");
+            didRun = true;
+        } );
+        assertThat(didRun).isTrue();
+    }
+
+    @Test
+    void withNonNullDoesNotRunBodyIfNull() {
+        didRun = false;
+        withNonNull(null, nonNullValue -> {
+            didRun = true;
+        } );
+        assertThat(didRun).isFalse();
+    }
+}

src/test/java/net/hostsharing/hsadminng/rbac/test/JsonBuilder.java

@@ -27,7 +27,7 @@ public class JsonBuilder {
      * @param value JSON value
      * @return this JsonBuilder
      */
-    public JsonBuilder with(final String key, final String value) {
+    public JsonBuilder with(final String key, final Object value) {
         try {
             jsonObject.put(key, value);
         } catch (JSONException e) {

src/test/java/net/hostsharing/hsadminng/test/TestUuidGenerator.java

@@ -63,6 +63,9 @@ public class TestUuidGenerator {
      * @return a constant UUID related to the given index
      */
     public static UUID use(final int index) {
+        if (staticallyUsedIndexes.contains(index)) {
+            throw new IllegalArgumentException("index " + index + " already used statically");
+        }
         staticallyUsedIndexes.add(index);
         return GIVEN_UUIDS.get(index);
     }