logdensityof should throw ArgumentError for non-density arg (#7)

Author: phipsgabler

src/interface.jl

@@ -19,7 +19,7 @@ export hasdensity
 @inline hasdensity(::Any) = false
 
 function check_hasdensity(d)
-    hasdensity(d) || throw("Object of type $(typeof(d)) is not compatible with DensityInterface")
+    hasdensity(d) || throw(ArgumentError("Object of type $(typeof(d)) is not compatible with DensityInterface"))
 end
 
 

test/test_interface.jl

@@ -16,6 +16,7 @@ DensityInterface.logdensityof(::MyDensity, x::Any) = norm(x)^2
     @test inverse(logfuncdensity) == logdensityof
 
     @test @inferred(hasdensity("foo")) == false
+    @test_throws ArgumentError logdensityof("foo")
 
     d1 = MyDensity()
     x = [1, 2, 3]