如何断言构造函数中抛出的异常？

Question

In my service class, I have this constructor.

public IngestService()
{
    _extractedFilePath = configuration["Path:Ingest"];

    if (string.IsNullOrEmpty(_extractedFilePath))
    {
        _logger.LogError($"Invalid conguration. Check appsettings.");
        throw new Exception("Invalid conguration. Check appsettings.");
    }
}

and I have this test using XUnit

[Fact]
public async Task WhenInvalidConstructor_ThenShouldThrowETest() {
        var _ingestService = new IngestService();
}

When I debug it, it can reach the constructor. But how do I capture the exception and assert the exception message "Invalid conguration. Check appsettings."?

Answer 1

Try this:

    Exception actualException = Assert.Throws<Exception>(() => new IngestService());
    Assert.Equal("Invalid conguration. Check appsettings.", actualException.Message);