NuGet, Testing and Analyzers

The everyday toolchain

NuGet is .NET's package manager: dotnet add package Serilog adds a <PackageReference> to the project file, and dotnet restore downloads packages. For multi-project solutions, Central Package Management (Directory.Packages.props) keeps versions in one place, and Directory.Build.props shares settings like Nullable and TreatWarningsAsErrors. Common test frameworks are xUnit, NUnit and MSTest; run them with dotnet test. Mocking libraries such as NSubstitute or Moq replace dependencies, and assertion libraries make failures readable. Roslyn analyzers run during build: the built-in .NET analyzers catch bugs and performance issues, configured through .editorconfig and <AnalysisLevel>; dotnet format applies code style. Use dotnet list package --vulnerable and --outdated to keep dependencies safe and current.

Build, test, analyse

Restore packages, compile with analyzers, then run tests, locally and in CI alike.

An xUnit test

Arrange, act, assert; [Theory] runs the same test with several inputs.

using Xunit;

public class BankAccountTests
{
    [Fact]
    public void Withdraw_more_than_balance_fails_and_keeps_balance()
    {
        var acct = new BankAccount("Asha") { Ifsc = "SBIN0001234" };
        acct.Deposit(100m);

        bool ok = acct.TryWithdraw(150m);

        Assert.False(ok);
        Assert.Equal(100m, acct.Balance);
    }

    [Theory]
    [InlineData(0)]
    [InlineData(-5)]
    public void Deposit_rejects_non_positive_amounts(int amount)
    {
        var acct = new BankAccount("Asha") { Ifsc = "SBIN0001234" };
        Assert.Throws<ArgumentOutOfRangeException>(() => acct.Deposit(amount));
    }
}

// dotnet new xunit -n Bank.Tests && dotnet add Bank.Tests reference Bank
// dotnet test

Make warnings fail the build

Warnings that never fail the build accumulate until nobody reads them. Turn on TreatWarningsAsErrors in new projects, and suppress specific rules in .editorconfig with a reason when you must.

Quick check: Where can you set shared properties such as Nullable for every project in a repository?

• Program.cs
• appsettings.json
• Directory.Build.props
• global usings