design-patterns/csharp/Singleton/Logger.UnitTest/LoggerTest.cs at main · wralith/design-patterns · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
namespace Logger.UnitTest;

public class LoggerTest
{
    [Fact]
    public void GetInstance_ReturnsSameInstance()
    {
        var instance1 = ConsoleLogger.GetInstance();
        var instance2 = ConsoleLogger.GetInstance();

        Assert.Same(instance1, instance2);
    }

    [Fact]
    public void Log_WritesMessageToConsole()
    {
        var logger = ConsoleLogger.GetInstance();
        string message = "test";
        string expected = $"Log Message: {message}";
        string actual;

        using (var writer = new StringWriter())
        {
            Console.SetOut(writer);
            logger.Log(message);

            actual = writer.ToString().Trim();
        }

        Assert.Equal(expected, actual);
    }
}