AnthonyGiretti/ILogger-extensions

Extensions on Ilogger for unit testing

Calzolari-ILogger-extensions

Extensions on Ilogger for unit testing

(NSusbtitute dependency)

ONLY WORKs WITH Microsoft.Extensions.Logging 2+

NOT WORKING WITH Microsoft.Extensions.Logging 3+, BECAUSE regression has been made, explanation here: dotnet/extensions#1319

Unfortunately NSubstitute doesn't handle "Any Type" feature, It can only ignore specifics type in matching calls

Must match your Microsoft.Extensions.Logging version in your project

Example:

If you use ILogger from dependency Microsoft.Extensions.Logging (>= 2.2.0), use package Microsoft.Extensions.Logging (>= 2.2.0.x)

Features

• Provides ILogger matching arguments check with a LogLevel, an exception and a message
• Provides ILogger matching arguments check with a LogLevel and a message
• Provides ILogger non matching arguments check (no logger called at all)
• Provides ILogger non matching arguments check with a LogLevel, an exception and a message
• Provides ILogger non matching arguments check with a LogLevel and a message

Usage with NSubstitute

Matching argument check with a LogLevel, exception and a message

Service:

public object GetData(string name)
{
    try 
    {
        return myService.Get(name);
    }
    catch (Exception e)
    {
        logger.LogError(e, "Error occured during Get execution");
        return string.Empty;
    }
}

Unit test:

public void When_exception_is_raised_should_log_error_exception()
{
    // Arrange
    var exception = new Exception("an error occured");
    myServiceMock.Get(Arg.Any<string>()).Throws(exception);

    // Act
    sut.GetData("test");

    // Assert
    loggerMock.ReceivedMatchingArgs(LogLevel.Error, exception, "Error occured during Get execution");
}

Matching argument check with a LogLevel and a message

Service:

public object GetData(string name)
{
    logger.LogDebug("Calling Get method");
    return myService.Get(name);
}

Unit test:

public void When_invoked_should_logDebug_should_be_called()
{
    // Arrange
    myServiceMock.Get(Arg.Any<string>()).Returns("Hello");

    // Act
    sut.GetData("test");

    // Assert
    loggerMock.ReceivedMatchingArgs(LogLevel.Debug, "Calling Get method");
}

Non matching argument check (logger hasn't been called at all)

Service:

public object GetData(string name)
{
    try
    {
        var result = myService.Get(name);
        logger.LogDebug("Get method called");
        return result;
    }
    catch (Exception e)
    {
        return string.Empty;
    }
}

Unit test:

public void When_invoked_logger_should_not_be_called()
{
    // Arrange
    myServiceMock.Get(Arg.Any<string>()).Throws(new Exception())

    // Act
    sut.GetData("test");

    // Assert
    loggerMock.DidNotReceiveMatchingArgs();
}

Non matching argument check for a specific LogLevel

Service:

public object GetData(string name)
{
    try
    {
        var result = myService.Get(name);
        logger.LogInformation("Calling Get method");
        return result;
    }
    catch (Exception e)
    {
        logger.LogError("Error occured during Get execution");
        return string.Empty;
    }
}

Unit test:

public void When_invoked_logError_should_not_be_called()
{
    // Arrange
    myServiceMock.Get(Arg.Any<string>()).Returns("Hello")

    // Act
    sut.GetData("test");

    // Assert
    loggerMock.DidNotReceiveMatchingArgs(LogLevel.Error);
}

Non matching argument check for a specific LogLevel and message

Service:

public object GetData(string name)
{
    try
    {
        logger.LogDebug("Before calling Get method");
        var result = myService.Get(name);
        logger.LogDebug("After calling Get method");
        return result;
    }
    catch (Exception e)
    {
        logger.LogError("Error occured during Get execution");
        return string.Empty;
    }
}

Unit test:

public void When_invoked_logDebug_after_calling_method_should_not_be_called()
{
    // Arrange
    myServiceMock.Get(Arg.Any<string>()).Throws(new Exception())

    // Act
    sut.GetData("test");

    // Assert
    loggerMock.ReceivedMatchingArgs(LogLevel.Debug, "Before calling Get method");
    loggerMock.ReceivedMatchingArgs(LogLevel.Error, "Error occured during Get execution");
    loggerMock.DidNotReceiveMatchingArgs(LogLevel.Debug, "After calling Get method");
}