Fix for type instability when using LKJChol (#548)

* concretize reshape in `reconstruct` for `LKJCholesky` to avoid type-instabilities

* added tests for `demo_lkjchol`

* bumped patch versionion

Project.toml

@@ -1,6 +1,6 @@
 name = "DynamicPPL"
 uuid = "366bfd00-2699-11ea-058f-f148b4cae6d8"
-version = "0.23.19"
+version = "0.23.20"
 
 [deps]
 AbstractMCMC = "80f14c24-f653-4e6a-9b94-39d6b0f70001"

src/utils.jl

@@ -238,7 +238,7 @@ reconstruct(::MatrixDistribution, val::AbstractMatrix{<:Real}) = copy(val)
 reconstruct(::Inverse{Bijectors.VecCorrBijector}, ::LKJ, val::AbstractVector) = copy(val)
 
 function reconstruct(dist::LKJCholesky, val::AbstractVector{<:Real})
-    return reconstruct(dist, reshape(val, size(dist)))
+    return reconstruct(dist, Matrix(reshape(val, size(dist))))
 end
 function reconstruct(dist::LKJCholesky, val::AbstractMatrix{<:Real})
     return Cholesky(val, dist.uplo, 0)

test/model.jl

@@ -25,6 +25,10 @@ function innermost_distribution_type(d::Distributions.Product)
     return dists[1]
 end
 
+is_typed_varinfo(::DynamicPPL.AbstractVarInfo) = false
+is_typed_varinfo(varinfo::DynamicPPL.TypedVarInfo) = true
+is_typed_varinfo(varinfo::DynamicPPL.SimpleVarInfo{<:NamedTuple}) = true
+
 @testset "model.jl" begin
     @testset "convenience functions" begin
         model = gdemo_default # defined in test/test_util.jl
@@ -329,4 +333,32 @@ end
             @test x_true.UL == result.x.UL
         end
     end
+
+    @testset "Type stability of models" begin
+        models_to_test = [
+            # FIXME: Fix issues with type-stability in `DEMO_MODELS`.
+            # DynamicPPL.TestUtils.DEMO_MODELS...,
+            DynamicPPL.TestUtils.demo_lkjchol(2),
+        ]
+        @testset "$(model.f)" for model in models_to_test
+            vns = DynamicPPL.TestUtils.varnames(model)
+            example_values = DynamicPPL.TestUtils.rand(model)
+            varinfos = filter(
+                is_typed_varinfo,
+                DynamicPPL.TestUtils.setup_varinfos(model, example_values, vns),
+            )
+            @testset "$(short_varinfo_name(varinfo))" for varinfo in varinfos
+                @test (@inferred(DynamicPPL.evaluate!!(model, varinfo, DefaultContext()));
+                true)
+
+                varinfo_linked = DynamicPPL.link(varinfo, model)
+                @test (
+                    @inferred(
+                        DynamicPPL.evaluate!!(model, varinfo_linked, DefaultContext())
+                    );
+                    true
+                )
+            end
+        end
+    end
 end