Harden wallet domain invariants and add regression tests

payguard-wallet/src/main/java/dev/amg/payguard/WalletApp.java

@@ -0,0 +1,12 @@
+package dev.amg.payguard;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class WalletApp {
+
+  public static void main(String[] args) {
+    SpringApplication.run(WalletApp.class, args);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/enums/FinancialAccountType.java

@@ -0,0 +1,9 @@
+package dev.amg.payguard.domain.enums;
+
+public enum FinancialAccountType {
+  USER_WALLET,
+  BANK_CLEARING,
+  COMPANY_REVENUE,
+  PROMOTIONAL_EXPENSE,
+  SETTLEMENT_SUSPENSE
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/enums/HoldStatus.java

@@ -0,0 +1,8 @@
+package dev.amg.payguard.domain.enums;
+
+public enum HoldStatus {
+  PENDING,
+  CAPTURED,
+  RELEASED,
+  EXPIRED
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/enums/LedgerEntryType.java

@@ -0,0 +1,6 @@
+package dev.amg.payguard.domain.enums;
+
+public enum LedgerEntryType {
+  DEBIT,
+  CREDIT
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/enums/TransactionStatus.java

@@ -0,0 +1,9 @@
+package dev.amg.payguard.domain.enums;
+
+public enum TransactionStatus {
+  INITIATED,
+  PENDING_SETTLEMENT,
+  SUCCESSFUL,
+  FAILED,
+  REVERSED
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/enums/TransactionType.java

@@ -0,0 +1,10 @@
+package dev.amg.payguard.domain.enums;
+
+public enum TransactionType {
+  DEPOSIT,
+  WITHDRAWAL,
+  P2P_TRANSFER,
+  PURCHASE,
+  REFUND,
+  FEE
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/enums/WalletStatus.java

@@ -0,0 +1,9 @@
+package dev.amg.payguard.domain.enums;
+
+public enum WalletStatus {
+  ACTIVE,
+  SUSPENDED_DEBIT,
+  SUSPENDED_CREDIT,
+  FROZEN,
+  CLOSED
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/FundsHoldCapturedEvent.java

@@ -0,0 +1,22 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.HoldId;
+import dev.amg.payguard.domain.value_object.Money;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record FundsHoldCapturedEvent(
+    UUID eventId, Instant occurredAt, HoldId holdId, WalletId walletId, Money amount)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static FundsHoldCapturedEvent now(
+      HoldId holdId, WalletId walletId, Money amount, Instant now) {
+    return new FundsHoldCapturedEvent(UUID.randomUUID(), now, holdId, walletId, amount);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/FundsHoldCreatedEvent.java

@@ -0,0 +1,27 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.HoldId;
+import dev.amg.payguard.domain.value_object.Money;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record FundsHoldCreatedEvent(
+    UUID eventId,
+    Instant occurredAt,
+    HoldId holdId,
+    WalletId walletId,
+    Money amount,
+    Instant expiresAt)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static FundsHoldCreatedEvent now(
+      HoldId holdId, WalletId walletId, Money amount, Instant expiresAt, Instant now) {
+    return new FundsHoldCreatedEvent(UUID.randomUUID(), now, holdId, walletId, amount, expiresAt);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/FundsHoldExpiredEvent.java

@@ -0,0 +1,22 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.HoldId;
+import dev.amg.payguard.domain.value_object.Money;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record FundsHoldExpiredEvent(
+    UUID eventId, Instant occurredAt, HoldId holdId, WalletId walletId, Money amount)
+    implements DomainEvent {
+  public static FundsHoldExpiredEvent now(
+      HoldId holdId, WalletId walletId, Money amount, Instant now) {
+    return new FundsHoldExpiredEvent(UUID.randomUUID(), now, holdId, walletId, amount);
+  }
+
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/FundsHoldReleasedEvent.java

@@ -0,0 +1,22 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.HoldId;
+import dev.amg.payguard.domain.value_object.Money;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record FundsHoldReleasedEvent(
+    UUID eventId, Instant occurredAt, HoldId holdId, WalletId walletId, Money amount)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static FundsHoldReleasedEvent now(
+      HoldId holdId, WalletId walletId, Money amount, Instant now) {
+    return new FundsHoldReleasedEvent(UUID.randomUUID(), now, holdId, walletId, amount);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/MoneyDepositedEvent.java

@@ -0,0 +1,22 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.Money;
+import dev.amg.payguard.domain.value_object.TransactionId;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record MoneyDepositedEvent(
+    UUID eventId, Instant occurredAt, TransactionId transactionId, WalletId walletId, Money amount)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static MoneyDepositedEvent now(
+      TransactionId transactionId, WalletId walletId, Money amount, Instant now) {
+    return new MoneyDepositedEvent(UUID.randomUUID(), now, transactionId, walletId, amount);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/MoneyWithdrawnEvent.java

@@ -0,0 +1,22 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.Money;
+import dev.amg.payguard.domain.value_object.TransactionId;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record MoneyWithdrawnEvent(
+    UUID eventId, Instant occurredAt, TransactionId transactionId, WalletId walletId, Money amount)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static MoneyWithdrawnEvent now(
+      TransactionId transactionId, WalletId walletId, Money amount, Instant now) {
+    return new MoneyWithdrawnEvent(UUID.randomUUID(), now, transactionId, walletId, amount);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/TransferCompletedEvent.java

@@ -0,0 +1,34 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.AccountId;
+import dev.amg.payguard.domain.value_object.Money;
+import dev.amg.payguard.domain.value_object.TransactionId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record TransferCompletedEvent(
+    UUID eventId,
+    Instant occurredAt,
+    TransactionId transactionId,
+    AccountId sourceAccountId,
+    AccountId destinationAccountId,
+    Money amount,
+    Money fee)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static TransferCompletedEvent now(
+      TransactionId transactionId,
+      AccountId source,
+      AccountId destination,
+      Money amount,
+      Money fee,
+      Instant now) {
+    return new TransferCompletedEvent(
+        UUID.randomUUID(), now, transactionId, source, destination, amount, fee);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/WalletClosedEvent.java

@@ -0,0 +1,18 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record WalletClosedEvent(UUID eventId, Instant occurredAt, WalletId walletId)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static WalletClosedEvent now(WalletId walletId, Instant now) {
+    return new WalletClosedEvent(UUID.randomUUID(), now, walletId);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/WalletCreatedEvent.java

@@ -0,0 +1,22 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.value_object.UserId;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.Currency;
+import java.util.UUID;
+
+public record WalletCreatedEvent(
+    UUID eventId, Instant occurredAt, WalletId walletId, UserId userId, Currency currency)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static WalletCreatedEvent now(
+      WalletId walletId, UserId userId, Currency currency, Instant now) {
+    return new WalletCreatedEvent(UUID.randomUUID(), now, walletId, userId, currency);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/event/WalletStatusChangedEvent.java

@@ -0,0 +1,27 @@
+package dev.amg.payguard.domain.event;
+
+import dev.amg.payguard.domain.enums.WalletStatus;
+import dev.amg.payguard.domain.value_object.WalletId;
+import domain.DomainEvent;
+import java.time.Instant;
+import java.util.UUID;
+
+public record WalletStatusChangedEvent(
+    UUID eventId,
+    Instant occurredAt,
+    WalletId walletId,
+    WalletStatus previousStatus,
+    WalletStatus newStatus,
+    String reason)
+    implements DomainEvent {
+  @Override
+  public Instant occurredOn() {
+    return occurredAt;
+  }
+
+  public static WalletStatusChangedEvent now(
+      WalletId walletId, WalletStatus previous, WalletStatus current, String reason, Instant now) {
+    return new WalletStatusChangedEvent(
+        UUID.randomUUID(), now, walletId, previous, current, reason);
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/exception/CurrencyMismatchException.java

@@ -0,0 +1,30 @@
+package dev.amg.payguard.domain.exception;
+
+import domain.DomainException;
+
+public class CurrencyMismatchException extends DomainException {
+  private static final long serialVersionUID = 1L;
+
+  public CurrencyMismatchException() {
+    this("Currency mismatch");
+  }
+
+  public CurrencyMismatchException(String message) {
+    super(message);
+  }
+
+  @Override
+  public String getErrorCode() {
+    return "CURRENCY_MISMATCH";
+  }
+
+  @Override
+  public String getTitle() {
+    return "Currency mismatch";
+  }
+
+  @Override
+  public int getHttpStatus() {
+    return 400;
+  }
+}

payguard-wallet/src/main/java/dev/amg/payguard/domain/exception/DoubleEntryImbalanceException.java

@@ -0,0 +1,30 @@
+package dev.amg.payguard.domain.exception;
+
+import domain.DomainException;
+
+public class DoubleEntryImbalanceException extends DomainException {
+  private static final long serialVersionUID = 1L;
+
+  public DoubleEntryImbalanceException() {
+    this("Double-entry transaction is imbalanced");
+  }
+
+  public DoubleEntryImbalanceException(String message) {
+    super(message);
+  }
+
+  @Override
+  public String getErrorCode() {
+    return "DOUBLE_ENTRY_IMBALANCE";
+  }
+
+  @Override
+  public String getTitle() {
+    return "Double-entry imbalance";
+  }
+
+  @Override
+  public int getHttpStatus() {
+    return 400;
+  }
+}