workflow setup

1-tests/Just.PreciseMath.Tests/DoubleDoubleTests.cs

@@ -0,0 +1,16 @@
+using Shouldly;
+using Xunit;
+
+namespace Just.PreciseMath.Tests;
+
+public class DoubleDoubleTests
+{
+    [Fact]
+    public void OneHasExpectedComponents()
+    {
+        DoubleDouble value = DoubleDouble.One;
+
+        value.High.ShouldBe(1.0);
+        value.Low.ShouldBe(0.0);
+    }
+}