I have a class with some fields/properties etc., of various types:

```
public string SomeStringData;
public int? SomeNullableIntegerData;
public SomeDataClass SomeSpecificData;
public int SomeIntegerData;

```

In part of my code, only the `SomeStringData` should be filled, and I want to test explicitly that. I use [FluentAssertions](https://github.com/dennisdoomen/FluentAssertions) and have

```
actual.SomeStringData.Should().Be("Whatever");

```

But how to test, that none of the other elements are not touched and still have their default value? I could, of course:

```
actual.SomeNullableIntegerData.Should().NotHaveValue("Must have no value.");
actual.SomeDataClass.Should().BeNull("Must have no value.");
actual.SomeNullableIntegerData.Should().Be(0, "Must have no value.");

```

**But, how to express more clearly that these items should have the default value?**

Like for example with an imaginary `BeDefault` operator:

```
actual.SomeNullableIntegerData.Should().BeDefault("Must have no value.");
actual.SomeDataClass.Should().BeDefault("Must have no value.");
actual.SomeNullableIntegerData.Should().BeDefault("Must have no value.");

```

Are there such options?