Rider

JetBrains Rider is a fast, cross-platform .NET IDE providing rich refactoring, dotTrace profiling, and first-class support for ASP.NET Core, Unity, and Unreal Engine.

When to Use

• Cross-Platform .NET / C# Development: Building high-performance ASP.NET Core web APIs, Blazor, and microservices on macOS, Linux, and Windows.
• Game Engine Engineering (Unity & Unreal): Profiling, debugging C# scripts, and integrating shaders with deep engine hooks.
• ReSharper-Powered Refactoring: Performing enterprise-scale code migrations, nullability analysis, and LINQ optimization.
• dotTrace & dotMemory Profiling: Identifying memory leaks, GC pressure, and multi-threaded execution locks.

Quick Start

1. Open Solution & Run

# Open solution via Rider CLI
rider MyProject.sln

2. Configure launchSettings.json

{
  "profiles": {
    "Development": {
      "commandName": "Project",
      "dotnetRunMessages": true,
      "launchBrowser": true,
      "applicationUrl": "https://localhost:7001;http://localhost:5001",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

• Select profile in top toolbar and press Ctrl + F5 (Run) or F5 (Debug).

Core Concepts

Modern .NET Solution & EditorConfig

Configuring code formatting, nullability, and C# 12/13 conventions via .editorconfig:

# .editorconfig
root = true

[*.cs]
indent_style = space
indent_size = 4
end_of_line = lf
charset = utf-8

# C# Formatting Rules
csharp_new_line_before_open_brace = all
csharp_indent_braces = false
csharp_prefer_braces = true:suggestion
csharp_style_var_when_type_is_apparent = true:suggestion
dotnet_style_null_propagation = true:suggestion
dotnet_naming_rule.async_methods_must_end_with_async.severity = warning

# Code Quality & Nullable Inspections
dotnet_diagnostic.CS8600.severity = error # Converting null literal to non-nullable
dotnet_diagnostic.CS8602.severity = error # Dereference of a possibly null reference
dotnet_diagnostic.CA1822.severity = warning # Member can be made static

High-Speed ASP.NET Core Fast Endpoints Configuration

Building modern, high-throughput C# microservices in Rider:

using FastEndpoints;

public class CreateUserRequest
{
    public required string Email { get; init; }
    public required string Name { get; init; }
}

public class CreateUserResponse
{
    public required Guid Id { get; init; }
    public required string Status { get; init; }
}

public class CreateUserEndpoint : Endpoint<CreateUserRequest, CreateUserResponse>
{
    public override void Configure()
    {
        Post("/api/v1/users");
        AllowAnonymous();
    }

    public override async Task HandleAsync(CreateUserRequest req, CancellationToken ct)
    {
        var userId = Guid.NewGuid();
        // Business logic execution
        await SendCreatedAtAsync<GetUserEndpoint>(
            new { id = userId },
            new CreateUserResponse { Id = userId, Status = "Created" },
            cancellation: ct
        );
    }
}

dotMemory Profiling & Memory Leak Detection

• Attach Rider dotMemory profiler to a running .NET process (Run -> Profile with dotMemory).
• Take snapshot before and after workload execution.
• Compare memory generations, pinned handles, and investigate retention paths for undisposed event handlers and singletons.

Common Patterns

Launch Settings Profile (.run/launchSettings.json)

Problem: Standardize ASP.NET Core environment variables across developers.
Solution: Configure launch profiles in launchSettings.json.

{
  "profiles": {
    "LocalDevelopment": {
      "commandName": "Project",
      "launchBrowser": false,
      "applicationUrl": "https://localhost:5001;http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development",
        "DOTNET_USE_POLLING_FILE_WATCHER": "1"
      }
    }
  }
}

Best Practices

Do:

• Enable Nullable Reference Types (<Nullable>enable</Nullable>) across all project files.
• Utilize Rider's integrated dotMemory and dotTrace for profiling GC allocations and high-CPU methods.
• Use Ctrl + Shift + R (Refactor This) for safe signature modifications, interface extraction, and inline methods.
• Enable Solution-Wide Analysis to catch compilation and architectural rule violations before committing.

Don't:

• Check in .idea/ workspace files or personal launch settings into Git.
• Ignore ReSharper yellow and red inspection warnings; resolve them continuously.
• Run synchronous blocking calls (.Result, .Wait()) on asynchronous Task operations; use await.

Troubleshooting

| Error | Cause | Solution | | -------------------------------------------------- | ---------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- | | Rider cannot find target .NET SDK | Multiple SDKs or wrong architecture installed (e.g. ARM64 vs x64 on Apple Silicon) | Set custom SDK path in Settings > Build, Execution, Deployment > Toolset and Build. | | Unity breakpoints not hitting | Rider plugin in Unity outdated or debugger attached to wrong process | Check Unity Package Manager for com.unity.ide.rider; ensure editor is attached to Unity Editor process. | | High memory consumption on multi-project solutions | Solution-wide analysis inspecting hundreds of projects simultaneously | Lower inspection severity in Settings > Editor > Inspection Settings or pause Solution-Wide Analysis. |

References

• Rider Documentation