formatting and added test for return-value and submodel

Author: torfjelde

src/submodel_macro.jl

@@ -225,7 +225,9 @@ function submodel(prefix_expr, expr, ctx=esc(:__context__))
     return if args_assign === nothing
         ctx = prefix_submodel_context(prefix, ctx)
         quote
-            $retval, $(esc(:__varinfo__)) = $(DynamicPPL._evaluate!!)($(esc(expr)), $(esc(:__varinfo__)), $(ctx))
+            $retval, $(esc(:__varinfo__)) = $(DynamicPPL._evaluate!!)(
+                $(esc(expr)), $(esc(:__varinfo__)), $(ctx)
+            )
             $retval
         end
     else

test/compiler.jl

@@ -570,5 +570,15 @@ end
 
         @model demo() = x ~ Normal()
         retval, svi = DynamicPPL.evaluate!!(demo(), SimpleVarInfo(), SamplingContext())
+
+        # Return-value when using `@submodel`
+        @model inner() = x ~ Normal()
+        # Without assignment.
+        @model outer() = @submodel inner()
+        @test outer()() isa Real
+
+        # With assignment.
+        @model outer() = @submodel x = inner()
+        @test outer()() isa Real
     end
 end