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Number

Describes the possible expectations for numbers.

ExpectationNegatedSummary
IsEqualToIsNotEqualToequal to the expected number
IsOneOfIsNotOneOfequal to one of the expected numbers
IsGreaterThanIsNotGreaterThangreater than the expected number
IsGreaterThanOrEqualToIsNotGreaterThanOrEqualTogreater than or equal to the expected number
IsLessThanIsNotLessThanless than the expected number
IsLessThanOrEqualToIsNotLessThanOrEqualToless than or equal to the expected number
IsBetweenIsNotBetweenbetween two numbers, both bounds included
IsPositiveIsNotPositivegreater than zero
IsNegativeIsNotNegativeless than zero
IsNaNIsNotNaNNaN (floating point numbers only)
IsFiniteIsNotFiniteneither infinite nor NaN (floating point numbers only)
IsInfiniteIsNotInfinitepositive or negative infinity (floating point numbers only)

Equality​

You can verify that the number is equal to another one or not:

int playCount = 42;

await Expect.That(playCount).IsEqualTo(42);
await Expect.That(playCount).IsNotEqualTo(41);

One of​

You can verify that the number is one of many alternatives:

int trackCount = 12;

await Expect.That(trackCount).IsOneOf(10, 12, 14);
await Expect.That(trackCount).IsNotOneOf(11, 13);

Greater than / less than​

You can verify that the number is greater than or less than (or equal to) another number, or that it is not:

int playCount = 42;

await Expect.That(playCount).IsGreaterThan(41);
await Expect.That(playCount).IsGreaterThanOrEqualTo(42);
await Expect.That(playCount).IsLessThan(43);
await Expect.That(playCount).IsLessThanOrEqualTo(42);
await Expect.That(playCount).IsNotGreaterThan(42);
await Expect.That(playCount).IsNotLessThan(42);

NaN is neither greater nor less than any number, so it satisfies IsNotGreaterThan(5) although it fails IsLessThanOrEqualTo(5).

Between​

You can verify that the number is between two numbers:

int playCount = 42;

await Expect.That(playCount).IsBetween(41).And(43);
await Expect.That(playCount).IsNotBetween(43).And(50);

Both bounds belong to the range, so IsNotBetween(42).And(50) fails for 42.

Positive / negative​

You can verify that the number is positive or negative, or that it is not:

await Expect.That(42).IsPositive();
await Expect.That(-3).IsNegative();
await Expect.That(0).IsNotPositive();
await Expect.That(0).IsNotNegative();

Zero and NaN are neither positive nor negative, so both IsNotPositive and IsNotNegative succeed for them.

.NET 8 or later

Below .NET 8 these expectations are only available for signed numbers. On .NET 8 or later they are available for every INumber<T>, including unsigned types.

NaN and infinity​

For floating point numbers you can verify that the number is NaN, finite or infinite, or that it is not:

await Expect.That(float.NaN).IsNaN();
await Expect.That(42.0).IsNotNaN();
await Expect.That(42.0).IsFinite();
await Expect.That(float.PositiveInfinity).IsInfinite();
await Expect.That(double.NaN).IsNotFinite().And.IsNotInfinite();

Tolerance​

The comparisons on this page, except the sign, NaN and infinity checks, accept a tolerance with Within, which widens the accepted range by the tolerance:

double duration = 42.1;

await Expect.That(duration).IsEqualTo(42).Within(0.2)
  .Because("we accept values between 41.8 and 42.2 (42 ± 0.2)");
await Expect.That(duration).IsOneOf(40, 42, 44).Within(0.2)
  .Because("we accept values between 39.8 and 40.2 or 41.8 and 42.2 or 43.8 and 44.2");
await Expect.That(duration).IsGreaterThan(42.2).Within(0.2)
  .Because("we accept values greater than 42.0 (42.2 - 0.2)");
await Expect.That(duration).IsLessThan(42).Within(0.2)
  .Because("we accept values less than 42.2 (42 + 0.2)");