Fix more tests

Author: penelopeysm

test/turing.jl

@@ -8,7 +8,10 @@
         return nothing
     end
 
-    @model logp_check() = x ~ Normal()
+    @model function logp_check()
+        a ~ Normal()
+        return b ~ Normal()
+    end
 
     n_samples = 1000
     model = demo()
@@ -55,8 +58,15 @@
         )
 
         chain_logp_check = sample(
-            logp_check(), Turing.Gibbs(:x => externalsampler(sampler)), 100; progress=false
+            logp_check(),
+            Turing.Gibbs(:a => externalsampler(sampler), :b => externalsampler(sampler)),
+            100;
+            progress=false,
+        )
+        @test isapprox(
+            logpdf.(Normal(), chain_logp_check[:a]) .+
+            logpdf.(Normal(), chain_logp_check[:b]),
+            chain_logp_check[:lp],
         )
-        @test isapprox(logpdf.(Normal(), chain_logp_check[:x]), chain_logp_check[:lp])
     end
 end