Coding Standards & Patterns

This page focuses on the technical standards and recurring patterns for .NET 10 development in InventoryAlert.

For a high-level overview of how to test the system, see the Test Structure & App Quality. For technical details on the three integration tiers, see Integration Testing Tiers.

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C# Coding Standards

Rule	Description
Primary Constructors	Use C# 12 primary constructors across all layers
CancellationToken ct	Must be the last parameter in every async method
No async without await	Remove async keyword; return Task.FromResult(...) instead (fixes CS1998)
string.Empty	Use over "" for empty string defaults on entity properties
null! suppressor	Forbidden unless accompanied by a comment explaining why
Private fields	_camelCase. Everything else: PascalCase
ILogger<T>	Use for all logging. Console.WriteLine is banned
AsNoTracking()	Required on all read-only EF Core queries
FluentValidation	Applied at Web layer only; controllers must not contain inline if validation

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Common Patterns

Transaction Capture Pattern

Ensure results are captured inside the transaction block to avoid returning stale or blank entities.

// ✅ GOOD — result assigned inside the lambda
PortfolioPositionResponse result = null!; 
await _unitOfWork.ExecuteTransactionAsync(async () => {
    var updated = await _repo.UpdateAsync(entity);
    result = MapToResponse(updated);
}, ct);
return result;

Async Polling Helper (Tests)

Used in E2E tests to wait for background worker side-effects.

await WaitHelper.WaitForConditionAsync(async () => {
    var res = await Client.GetAsync("/api/v1/notifications");
    return res.IsSuccessStatusCode;
}, timeoutSeconds: 15);

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Git Commit Convention

Follow the standard type(scope): message format.

Type	Description
feat	New feature
fix	Bug fix
test	Adding or updating tests
refactor	Code change that neither fixes a bug nor adds a feature
docs	Documentation only changes
chore	Maintenance tasks

Scopes: domain, infra, api, worker, ui, tests.

Example: feat(api): add position bulk import