ViIvanov

using System.Runtime.InteropServices;

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

if(args is []) {
  args = ["--filter", "*"];
}//if

BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args);

ViIvanov

/* Debugged application */

using System;

static class Program
{
  static void Main(string[] args) {
    Console.WriteLine(args?.Length); // Step into Specific, Console.WriteLine here
  }
}

ViIvanov

// Before
var dictionary1 = new Dictionary<int, string> {
  { 1, "One" },
  { 2, "Two" },
};

// After
var dictionary2 = new Dictionary<int, string> {
  [1] = "One",
  [2] = "Two",

ViIvanov

using System;

class Program
{
  static void Main() {
    var thing = new Thing();
    if(thing.A && thing == null) {
      Console.WriteLine("thing == null");
    }//if
  }

ViIvanov

using System.Collections.Generic;

// ReSharper disable once CheckNamespace
class MultiDictionary<TKey, TValue> : Dictionary<TKey, IList<TValue>>
{
  public void Add(TKey key, params TValue[] values) { }
}

static class Program
{

ViIvanov

using System;
using System.Linq;

static class Program
{
  static void Main(string[] args) {
    var lengths = args.Select(item => item.Length);
    // "lengths" can be enumerated a few times, depending on a size of "args".
    var xxx = args.Select(item => lengths.Select(x => x));
  }

ViIvanov

using System;
using System.Collections.Generic;

static class Program
{
  static void Add(IReadOnlyCollection<object> items) { }
  static void Add(IEnumerable<IReadOnlyCollection<object>> items) { }

  static void Main() {
    var list = new List<object[]>();

ViIvanov

// Overload of Debug.Assert with detailMessageFormat does not supported

// Debug.Assert has an overload with detailMessageFormat parameter: https://msdn.microsoft.com/en-us/library/cc190597(v=vs.110).aspx.

// This overload does not supported by R#:
// * No syntax highlighting and no validation of format arguments
// * Code analysises does not recognize this calls (null check not works)

class Program
{

ViIvanov

using System;

class Program
{
  static void Main() {
    var x = DateTime.Now.Day > 10 ? 1 : new Program() ?? default(object);
  }
}

ViIvanov

void Method(Entity entity) {
  if(entity == null) {
    throw new ArgumentNullException(nameof(entity));
  } else if(entity.Some.Property > 0) {
    throw new ArgumentException(stringanize(entity.Some.Property > 0), nameof(entity));
  }//if
  
  // "stringanize" makes a string from an expression
  // and when we are renamed "Some" or "Property"
  // string is updated!