Add Supposition-based test for construction of degenerate intervals using Rationals

Author: bvrb

test/interval_tests/supposition/numeric.jl

@@ -0,0 +1,21 @@
+using Test
+using IntervalArithmetic
+using Supposition, Supposition.Data
+
+@testset "Rational tests" begin
+    # Define number generators
+    #intgen = Data.Integers(typemin(Int)+1,typemax(Int)) # Don't allow den==typemin(Int) to avoid overflow
+    intgen = Data.Integers(typemin(Int8)+Int8(1),typemax(Int8)) # Don't allow den==typemin(Int8) to avoid overflow
+    rationalgen = @composed function generate_rational(num=intgen, den=intgen)
+        assume!(!(iszero(num) && iszero(den)))
+        return num // den
+    end
+
+    # Check properties
+    @check function degenerate_interval(r=rationalgen)
+        x = interval(r)
+        y = interval(r, r)
+        assume!(!any(decoration.((x,y)) .== ill)) # Exclude ill-formed intervals
+        isequal_interval(x, y)
+    end
+end