Fix loop in ADCheck tests

Author: penelopeysm

test/ad.jl

@@ -214,16 +214,18 @@ end
 @testset verbose = true "AD / ADTypeCheckContext" begin
     # This testset ensures that samplers or optimisers don't accidentally
     # override the AD backend set in it.
-    @testset "Check ADType" begin
-        seed = 123
-        alg = HMC(0.1, 10; adtype=adtype)
-        m = DynamicPPL.contextualize(
-            gdemo_default, ADTypeCheckContext(adtype, gdemo_default.context)
-        )
-        # These will error if the adbackend being used is not the one set.
-        sample(StableRNG(seed), m, alg, 10)
-        maximum_likelihood(m; adtype=adbackend)
-        maximum_a_posteriori(m; adtype=adbackend)
+    @testset "adtype=$adtype" for adtype in ADTYPES
+        @testset "Check ADType" begin
+            seed = 123
+            alg = HMC(0.1, 10; adtype=adtype)
+            m = DynamicPPL.contextualize(
+                gdemo_default, ADTypeCheckContext(adtype, gdemo_default.context)
+            )
+            # These will error if the adbackend being used is not the one set.
+            sample(StableRNG(seed), m, alg, 10)
+            maximum_likelihood(m; adtype=adtype)
+            maximum_a_posteriori(m; adtype=adtype)
+        end
     end
 end