From b3fc8b6e45cee5f6548f402388ec0f7cb5c3f02f Mon Sep 17 00:00:00 2001
From: Michal Zeman <>
Date: Sun, 22 Sep 2019 11:17:29 +0200
Subject: [PATCH] Transaction aggregate refactoring related to status

---
 .../domain/TransactionAggregate.java          | 30 ++++------
 .../transaction/domain/TransactionState.java  |  2 +
 .../transaction/domain/TransactionStatus.java |  8 +++
 .../command/TransactionCommandHandler.java    |  5 +-
 .../domain/event/FinishTransactionFailed.java |  3 +
 .../domain/TransactionAggregateTest.java      | 59 ++++++++++++++++++-
 6 files changed, 87 insertions(+), 20 deletions(-)
 create mode 100644 bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionStatus.java

diff --git a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregate.java b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregate.java
index 7970e73..66de9b6 100644
--- a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregate.java
+++ b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregate.java
@@ -11,13 +11,6 @@ import java.math.BigDecimal;
 
 public class TransactionAggregate {
 
-  enum State {
-    INITIALIZED,
-    CREATED,
-    FINISHED,
-    FAILED
-  }
-
   private Id aggregateId;
 
   private Id fromAccount;
@@ -26,15 +19,15 @@ public class TransactionAggregate {
 
   private BigDecimal amount;
 
-  private State state;
+  private TransactionStatus status;
 
   public TransactionAggregate(String aggregateId) {
     this.aggregateId = new Id(aggregateId);
-    state = State.INITIALIZED;
+    status = TransactionStatus.INITIALIZED;
   }
 
   public TransactionCreated validateCreateTransaction(CreateTransaction command) {
-    if (state == State.INITIALIZED) {
+    if (status == TransactionStatus.INITIALIZED) {
       Id.validate(command.fromAccountId(), command.toAccountId());
       if (command.amount().compareTo(BigDecimal.ZERO) <= 0) {
         throw new RuntimeException(String.format("Amount can't be %s", command.amount()));
@@ -48,13 +41,13 @@ public class TransactionAggregate {
           .toAccountId(command.toAccountId())
           .build();
     } else {
-      throw new RuntimeException(String.format("Can't be applied command %s, aggregate is in state %s",
-          command, this.state));
+      throw new RuntimeException(String.format("Can't be applied command %s, aggregate is in TransactionStatus %s",
+          command, this.status));
     }
   }
 
   public TransactionFinished validateFinishTransaction(FinishTransaction command) {
-    if (state == State.CREATED) {
+    if (status == TransactionStatus.CREATED) {
       return TransactionFinished.builder()
           .aggregateId(aggregateId.getValue())
           .correlationId(command.correlationId())
@@ -62,7 +55,7 @@ public class TransactionAggregate {
           .toAccountId(toAccount.getValue())
           .build();
     } else {
-      throw new RuntimeException(String.format("Transaction in the state: %s can't be finished!", state));
+      throw new RuntimeException(String.format("Transaction in the state: %s can't be finished!", status));
     }
   }
 
@@ -70,26 +63,27 @@ public class TransactionAggregate {
     this.fromAccount = new Id(created.fromAccountId());
     this.toAccount = new Id(created.toAccountId());
     this.amount = created.amount();
-    this.state = State.CREATED;
+    this.status = TransactionStatus.CREATED;
     return this;
   }
 
   public TransactionAggregate applyTransactionFinished(TransactionFinished event) {
-    this.state = State.FINISHED;
+    this.status = TransactionStatus.FINISHED;
     return this;
   }
 
   public TransactionAggregate applyTransactionFailed(TransactionFailed event) {
-    this.state = State.FAILED;
+    this.status = TransactionStatus.FAILED;
     return this;
   }
 
-  public TransactionState getState() {
+  public TransactionState getStatus() {
     return TransactionState.builder()
         .amount(amount)
         .fromAccountId(fromAccount.getValue())
         .toAccountId(toAccount.getValue())
         .aggregateId(aggregateId.getValue())
+        .status(this.status)
         .build();
   }
 }
diff --git a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionState.java b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionState.java
index 9f81b57..6bc7858 100644
--- a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionState.java
+++ b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionState.java
@@ -15,6 +15,8 @@ public interface TransactionState {
 
   BigDecimal amount();
 
+  TransactionStatus status();
+
   static ImmutableTransactionState.Builder builder() {
     return ImmutableTransactionState.builder();
   }
diff --git a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionStatus.java b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionStatus.java
new file mode 100644
index 0000000..97da195
--- /dev/null
+++ b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionStatus.java
@@ -0,0 +1,8 @@
+package com.mz.reactor.ddd.reactorddd.transaction.domain;
+
+public enum TransactionStatus {
+  INITIALIZED,
+  CREATED,
+  FINISHED,
+  FAILED
+}
diff --git a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/command/TransactionCommandHandler.java b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/command/TransactionCommandHandler.java
index c24f4eb..5521e35 100644
--- a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/command/TransactionCommandHandler.java
+++ b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/command/TransactionCommandHandler.java
@@ -58,7 +58,10 @@ public class TransactionCommandHandler implements CommandHandler<TransactionAggr
   public CommandResult execute(TransactionAggregate aggregate, TransactionCommand command) {
     if (command instanceof CreateTransaction) {
       return doCreateTransaction(aggregate, (CreateTransaction) command);
-    } else {
+    }
+    if (command instanceof FinishTransaction) {
+      return doFinishTransaction(aggregate, (FinishTransaction) command);
+    }else {
       return CommandResult.badCommand();
     }
   }
diff --git a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/event/FinishTransactionFailed.java b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/event/FinishTransactionFailed.java
index 5912fdf..a31fde3 100644
--- a/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/event/FinishTransactionFailed.java
+++ b/bank-account/transaction-domain/src/main/java/com/mz/reactor/ddd/reactorddd/transaction/domain/event/FinishTransactionFailed.java
@@ -2,6 +2,9 @@ package com.mz.reactor.ddd.reactorddd.transaction.domain.event;
 
 import org.immutables.value.Value;
 
+/**
+ * this event is fired only when someone is trying to finish transaction which is not in proper status
+ */
 @Value.Immutable
 public interface FinishTransactionFailed extends TransactionEvent {
 
diff --git a/bank-account/transaction-domain/src/test/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregateTest.java b/bank-account/transaction-domain/src/test/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregateTest.java
index 42d8db3..d3ea921 100644
--- a/bank-account/transaction-domain/src/test/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregateTest.java
+++ b/bank-account/transaction-domain/src/test/java/com/mz/reactor/ddd/reactorddd/transaction/domain/TransactionAggregateTest.java
@@ -3,6 +3,7 @@ package com.mz.reactor.ddd.reactorddd.transaction.domain;
 import com.mz.reactor.ddd.reactorddd.transaction.domain.command.CreateTransaction;
 import com.mz.reactor.ddd.reactorddd.transaction.domain.command.FinishTransaction;
 import com.mz.reactor.ddd.reactorddd.transaction.domain.event.TransactionCreated;
+import com.mz.reactor.ddd.reactorddd.transaction.domain.event.TransactionFailed;
 import com.mz.reactor.ddd.reactorddd.transaction.domain.event.TransactionFinished;
 import org.junit.jupiter.api.Test;
 
@@ -68,7 +69,7 @@ class TransactionAggregateTest {
         .build();
 
     var aggregate = new TransactionAggregate(aggregateId);
-    var state = aggregate.applyTransactionCreated(event).getState();
+    var state = aggregate.applyTransactionCreated(event).getStatus();
 
     assertEquals(state.aggregateId(), aggregateId);
     assertEquals(state.toAccountId(), toAccountId);
@@ -125,9 +126,65 @@ class TransactionAggregateTest {
 
   @Test
   void applyTransactionFinished() {
+    //given
+    var aggregateId = UUID.randomUUID().toString();
+    var correlationId = UUID.randomUUID().toString();
+    var toAccountId = UUID.randomUUID().toString();
+    var fromAccountId = UUID.randomUUID().toString();
+
+    var event = TransactionCreated.builder()
+        .aggregateId(aggregateId)
+        .correlationId(correlationId)
+        .amount(BigDecimal.TEN)
+        .fromAccountId(fromAccountId)
+        .toAccountId(toAccountId)
+        .build();
+
+    var aggregate = new TransactionAggregate(aggregateId);
+    aggregate.applyTransactionCreated(event);
+
+    //when
+    var transactionFinished = TransactionFinished.builder()
+        .toAccountId(toAccountId)
+        .fromAccountId(fromAccountId)
+        .aggregateId(aggregateId)
+        .build();
+    var state = aggregate.applyTransactionFinished(transactionFinished).getStatus();
+
+    //then
+    assertEquals(state.status(), TransactionStatus.FINISHED);
   }
 
   @Test
   void applyTransactionFailed() {
+    //given
+    var aggregateId = UUID.randomUUID().toString();
+    var correlationId = UUID.randomUUID().toString();
+    var toAccountId = UUID.randomUUID().toString();
+    var fromAccountId = UUID.randomUUID().toString();
+
+    var event = TransactionCreated.builder()
+        .aggregateId(aggregateId)
+        .correlationId(correlationId)
+        .amount(BigDecimal.TEN)
+        .fromAccountId(fromAccountId)
+        .toAccountId(toAccountId)
+        .build();
+
+    var aggregate = new TransactionAggregate(aggregateId);
+    aggregate.applyTransactionCreated(event);
+
+    //when
+    var transactionFailed = TransactionFailed.builder()
+        .toAccountId(toAccountId)
+        .fromAccountId(fromAccountId)
+        .aggregateId(aggregateId)
+        .amount(BigDecimal.TEN)
+        .build();
+    var state = aggregate.applyTransactionFailed(transactionFailed).getStatus();
+
+    //then
+    assertEquals(state.status(), TransactionStatus.FAILED);
+    assertEquals(state.amount(), BigDecimal.TEN);
   }
 }
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