
using Xunit;
using Xunit;
using System;
using System.IO;

namespace ConsoleApp {
    public class ProgramTests {
        [Fact(DisplayName = "PrintNumberPyramid prints correct pyramid for 5 rows")]
        public void PrintNumberPyramid_PrintsCorrectPyramid_5Rows()
        {
            var sw = new StringWriter();
            Console.SetOut(sw);
            Program.PrintNumberPyramid(5);
            string[] expected = {
                "    1",
                "   1 2",
                "  1 2 3",
                " 1 2 3 4",
                "1 2 3 4 5"
            };
            string[] output = sw.ToString().Split(new[] { '\\n', '\\r' }, StringSplitOptions.RemoveEmptyEntries);
            Assert.Equal(expected.Length, output.Length);
            for (int i = 0; i < expected.Length; i++)
            {
                Assert.Equal(expected[i], output[i]);
            }
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }
        [Fact(DisplayName = "PrintNumberPyramid prints correct pyramid for 1 row")]
        public void PrintNumberPyramid_PrintsCorrectPyramid_1Row()
        {
            var sw = new StringWriter();
            Console.SetOut(sw);
            Program.PrintNumberPyramid(1);
            string output = sw.ToString().TrimEnd();
            Assert.Equal("1", output);
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }
        [Fact(DisplayName = "PrintNumberPyramid prints correct pyramid for 3 rows")]
        public void PrintNumberPyramid_PrintsCorrectPyramid_3Rows()
        {
            var sw = new StringWriter();
            Console.SetOut(sw);
            Program.PrintNumberPyramid(3);
            string[] expected = {
                "  1",
                " 1 2",
                "1 2 3"
            };
            string[] output = sw.ToString().Split(new[] { '\\n', '\\r' }, StringSplitOptions.RemoveEmptyEntries);
            Assert.Equal(expected.Length, output.Length);
            for (int i = 0; i < expected.Length; i++)
            {
                Assert.Equal(expected[i], output[i]);
            }
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }
        [Fact(DisplayName = "PrintNumberPyramid prints nothing for 0 rows")]
        public void PrintNumberPyramid_PrintsNothingForZeroRows()
        {
            var sw = new StringWriter();
            Console.SetOut(sw);
            Program.PrintNumberPyramid(0);
            string output = sw.ToString();
            Assert.True(string.IsNullOrEmpty(output.Trim()), "Expected no output for 0 rows");
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }
        [Fact(DisplayName = "PrintNumberPyramid prints nothing for negative rows")]
        public void PrintNumberPyramid_PrintsNothingForNegativeRows()
        {
            var sw = new StringWriter();
            Console.SetOut(sw);
            Program.PrintNumberPyramid(-3);
            string output = sw.ToString();
            Assert.True(string.IsNullOrEmpty(output.Trim()), "Expected no output for negative rows");
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }
    }
}

ProgramTests.cs

The output should look like that:
```
    1
   1 2
  1 2 3
 1 2 3 4
1 2 3 4 5
```

Note

Deepen your understanding of C# loops with a hands-on, challenge-driven course. Explore for, while, and do-while loops, master nested structures, generate patterns, and tackle real-world problems. Each section alternates between engaging theory and practical coding challenges to ensure you build both conceptual understanding and practical fluency.

Challenge: Print Number Pyramid

Solution