Support ADTypes.NoAutoDiff

Author: oschulz

DifferentiationInterface/src/utils/check.jl

@@ -16,9 +16,17 @@ function check_available(backend::MixedMode)
            check_available(reverse_backend(backend))
 end
 
+@static if isdefined(ADTypes, :NoAutoDiff)
+    check_available(::ADTypes.NoAutoDiff) = throw(ADTypes.NoAutoDiffSelectedError())
+end
+
 """
     check_inplace(backend)
 
 Check whether `backend` supports differentiation of in-place functions and return a `Bool`.
 """
 check_inplace(backend::AbstractADType) = Bool(inplace_support(backend))
+
+@static if isdefined(ADTypes, :NoAutoDiff)
+    check_inplace(::ADTypes.NoAutoDiff) = throw(ADTypes.NoAutoDiffSelectedError())
+end

DifferentiationInterface/test/Core/ZeroBackends/test.jl

@@ -10,6 +10,11 @@ using Test
 
 LOGGING = get(ENV, "CI", "false") == "false"
 
+if isdefined(ADTypes, :NoAutoDiff)
+    @test_throws NoAutoDiffSelectedError check_available(NoAutoDiff())
+    @test_throws NoAutoDiffSelectedError check_inplace(NoAutoDiff())
+end
+
 zero_backends = [AutoZeroForward(), AutoZeroReverse()]
 
 for backend in zero_backends