Range

RangeAttribute supplies a sequence of values for one parameter on a parameterized test method.

Once you supply explicit data sources (such as Range, Values, Random, etc.) for any parameter on that method, you must specify sources for every parameter—see Parameterized Tests.

By default, NUnit merges parameters combinatorially (every combination). Use Sequential, Pairwise, or another combining strategy on the method to change pairing behavior.

Constructors

RangeAttribute(int from, int to)
RangeAttribute(uint from, uint to)
RangeAttribute(long from, long to)
RangeAttribute(ulong from, ulong to)
RangeAttribute(int from, int to, int step)
RangeAttribute(uint from, uint to, uint step)
RangeAttribute(long from, long to, long step)
RangeAttribute(ulong from, ulong to, ulong step)
RangeAttribute(float from, float to, float step)
RangeAttribute(double from, double to, double step)
Parameter Type Description
from numeric First yielded value
to numeric End of the progression; yielded while stepping toward this bound without crossing it
step numeric Increment between values (required for float/double; when omitted on signed integral types from/to, NUnit uses 1 or −1, matching whether from < to or from > to)

Unsigned uint / ulong ranges require to ≥ from and a positive step (no automatic downward ranges). Floating-point generators stop at the last value reached before arithmetic would overshoot to; if from/to/step produce no exact landing on to, to itself might not appear.

Applies To

Method Parameters Test Methods Test Fixtures (Classes) Assembly
✅ ❌ ❌ ❌

Example

The following test will be executed nine times.

[Test]
public void MyTest(
    [Values(1, 2, 3)] int x,
    [Range(0.2, 0.6, 0.2)] double d)
{
    Assert.That(x, Is.GreaterThan(0));
    Assert.That(d, Is.GreaterThan(0.0));
}

The MyTest method is called nine times, as follows:

MyTest(1, 0.2)
MyTest(1, 0.4)
MyTest(1, 0.6)
MyTest(2, 0.2)
MyTest(2, 0.4)
MyTest(2, 0.6)
MyTest(3, 0.2)
MyTest(3, 0.4)
MyTest(3, 0.6)

Notes

  1. Annotate [Range] directly on the method parameter. AllowMultiple is true, so repeat the attribute if you want several disjoint spans merged for the same argument.
  2. Signed integral two-argument constructors pick default step +1 or −1, so [Range(5, 1)] yields a descending sequence. Unsigned constructors throw if from > to.
  3. Resulting Cartesian products still depend on whichever combining attributes appear on the test method (Combinatorial by default).
  4. float/double overloads always require an explicit step; there is no two-argument floating-point shortcut.

See Also