{"id":2288,"date":"2026-07-20T12:43:14","date_gmt":"2026-07-20T10:43:14","guid":{"rendered":"https:\/\/kindsonthegenius.com\/blog\/simple-example-of-test-driven-developmenttdd-in-visual-studio-c-step-by-step-tutorial\/"},"modified":"2026-08-26T21:23:29","modified_gmt":"2026-08-26T19:23:29","slug":"simple-example-of-test-driven-developmenttdd-in-visual-studio-c-step-by-step-tutorial","status":"publish","type":"post","link":"https:\/\/kindsonthegenius.com\/blog\/simple-example-of-test-driven-developmenttdd-in-visual-studio-c-step-by-step-tutorial\/","title":{"rendered":"Simple Example of Test-Driven Development(TDD) in Visual Studio C# \u2013 Step by Step Tutorial"},"content":{"rendered":"

<\/p>\n

Updated August 2026 \u2014 full tutorial restored for this URL.<\/em><\/p>\n

This tutorial shows TDD in Visual Studio<\/strong> with C#<\/strong> and xUnit<\/strong> \u2014 same kata style as the JavaScript post.<\/p>\n

JS twin: TDD in JavaScript<\/a>.<\/p>\n

    \n
  1. Create projects<\/a><\/li>\n
  2. Red \u2013 first test<\/a><\/li>\n
  3. Green \u2013 implement<\/a><\/li>\n
  4. Refactor and extend<\/a><\/li>\n
  5. Tips in Visual Studio<\/a><\/li>\n<\/ol>\n

    1. Create projects<\/strong><\/p>\n

    dotnet new classlib -n StringCalc\ndotnet new xunit -n StringCalc.Tests\ndotnet add StringCalc.Tests reference StringCalc\n<\/code><\/pre>\n
    Open the solution in Visual Studio; Test Explorer will discover xUnit tests.<\/p>\n
    2. Red \u2013 first test<\/strong><\/p>\n
    using Xunit;\n\npublic class CalculatorTests\n{\n    [Fact]\n    public void Empty_returns_zero()\n    {\n        var calc = new Calculator();\n        Assert.Equal(0, calc.Add(\"\"));\n    }\n}\n<\/code><\/pre>\n
    Build \u2014 fails until Calculator<\/code> exists.<\/p>\n
    3. Green \u2013 implement<\/strong><\/p>\n
    public class Calculator\n{\n    public int Add(string numbers)\n    {\n        if (string.IsNullOrEmpty(numbers)) return 0;\n        return 0;\n    }\n}\n<\/code><\/pre>\n
    4. Refactor and extend<\/strong><\/p>\n
    [Theory]\n[InlineData(\"1\", 1)]\n[InlineData(\"1,2,3\", 6)]\npublic void Sums_comma_separated(string input, int expected)\n{\n    Assert.Equal(expected, new Calculator().Add(input));\n}\n<\/code><\/pre>\n
    public int Add(string numbers)\n{\n    if (string.IsNullOrEmpty(numbers)) return 0;\n    return numbers.Split(',').Select(int.Parse).Sum();\n}\n<\/code><\/pre>\n
    5. Tips in Visual Studio<\/strong><\/p>\n
      \n
    • Use Test Explorer \u2192 Run All after each tiny change.<\/li>\n
    • Keep production code in the class library, tests in the test project.<\/li>\n
    • NUnit works the same idea with [Test]<\/code> \/ [TestCase]<\/code>.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
      Updated August 2026 \u2014 full tutorial restored for this URL. This tutorial shows TDD in Visual Studio with C# and xUnit \u2014 same kata style … <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"pagelayer_contact_templates":[],"_pagelayer_content":"","footnotes":""},"categories":[35],"tags":[],"class_list":["post-2288","post","type-post","status-publish","format-standard","hentry","category-algorithms"],"acf":[],"_links":{"self":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts\/2288","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/comments?post=2288"}],"version-history":[{"count":2,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts\/2288\/revisions"}],"predecessor-version":[{"id":2465,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts\/2288\/revisions\/2465"}],"wp:attachment":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/media?parent=2288"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/categories?post=2288"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/tags?post=2288"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}