Reduce TransactionAggregate.StartTransaction parameter count with start context object

[Copilot]

TransactionAggregateExtensions.StartTransaction exceeded the repository’s parameter-count limit by taking 8 inputs plus the aggregate receiver. This change reduces the method’s surface area without changing transaction-start behavior by grouping the merchant/device identity inputs into a dedicated context object.

• API shape

  • Introduce TransactionStartContext to carry:
    • EstateId
    • MerchantId
    • DeviceIdentifier
  • Update StartTransaction to accept the context object instead of three separate parameters.

• Aggregate validation

  • Move estate/merchant/device validation onto TransactionStartContext.
  • Add an explicit invalid-result path when the context itself is null.

• Call site updates

  • Update business logic, shared test data builders, and aggregate tests to construct and pass TransactionStartContext.
  • Reduce repeated test setup in TestData with a shared CreateTransactionStartContext() helper.

• Safety / consistency

  • Make TransactionStartContext immutable with init setters to avoid post-construction mutation.
  • Add focused aggregate coverage for the null-context case.

Result result = transactionAggregate.StartTransaction(
    command.TransactionDateTime,
    command.TransactionNumber,
    transactionType,
    transactionReference,
    new TransactionStartContext
    {
        EstateId = command.EstateId,
        MerchantId = command.MerchantId,
        DeviceIdentifier = command.DeviceIdentifier
    },
    amount);

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• f.feedz.io
  • Triggering command: /usr/bin/dotnet dotnet test TransactionProcessor.Tests.csproj --filter VerifyBootstrapperIsValid --no-restore -nologo (dns block)
  • Triggering command: /usr/bin/dotnet dotnet test TransactionProcessor.Aggregates.Tests.csproj --filter TransactionAggregate_StartTransaction -p:RestoreIgnoreFailedSources=true -nologo (dns block)
  • Triggering command: /opt/hostedtoolcache/CodeQL/2.24.3/x64/codeql/csharp/tools/linux64/Semmle.Autobuild.CSharp /opt/hostedtoolcache/CodeQL/2.24.3/x64/codeql/csharp/tools/linux64/Semmle.Autobuild.CSharp (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Complexity] Method TransactionAggregateExtensions::StartTransaction has 9 parameters (limit is 8)</issue_title>
<issue_description>Codacy ID: c680e46466cc8832f3ade1dddbcbb6e9

File: TransactionProcessor.Aggregates/TransactionAggregate.cs
Line: 495
Rule: Complexity (Warning)
Commit: d86ddd7f1bcabe1f21d4be000e4eda81d82ca1d5

Message: Method TransactionAggregateExtensions::StartTransaction has 9 parameters (limit is 8)

**Code Snippet:**
```csharp
        public static Result StartTransaction(this TransactionAggregate aggregate, 
```

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Complexity] Method TransactionAggregateExtensions::StartTransaction has 9 parameters (limit is 8) #1403

---

🔒 GitHub Advanced Security automatically protects Copilot coding agent pull requests. You can protect all pull requests by enabling Advanced Security for your repositories. Learn more about Advanced Security.