fixed names_values and added tests (#2021)

Author: torfjelde

src/inference/Inference.jl

@@ -297,23 +297,23 @@ function names_values(extra_data::AbstractVector{<:NamedTuple{names}}) where nam
     return collect(names), values
 end
 
-function names_values(extra_data::AbstractVector{<:NamedTuple})
+function names_values(xs::AbstractVector{<:NamedTuple})
     # Obtain all parameter names.
-    names_set = Set(Symbol[])
-    for data in extra_data
-        for name in names(data)
-            push!(extra_names_set, name)
+    names_set = Set{Symbol}()
+    for x in xs
+        for k in keys(x)
+            push!(names_set, k)
         end
     end
-    extra_names = collect(extra_names_set)
+    names_unique = collect(names_set)
 
     # Extract all values as matrix.
     values = [
-        hasfield(data, name) ? missing : getfield(data, name)
-        for data in extra_data, name in extra_names
+        haskey(x, name) ? x[name] : missing
+        for x in xs, name in names_unique
     ]
 
-    return extra_names, values
+    return names_unique, values
 end
 
 getlogevidence(transitions, sampler, state) = missing

test/inference/Inference.jl

@@ -523,4 +523,14 @@
         vdemo3kw(; T) = vdemo3(T)
         sample(vdemo3kw(; T=Vector{Float64}), alg, 250)
     end
+
+    @testset "names_values" begin
+        ks, xs = Turing.Inference.names_values([
+            (a=1,),
+            (b=2,),
+            (a=3, b=4)
+        ])
+        @test all(xs[:, 1] .=== [1, missing, 3])
+        @test all(xs[:, 2] .=== [missing, 2, 4])
+    end
 end