From aeb5e03fdfe6958e4f79d9ccc5b01b84b93371ff Mon Sep 17 00:00:00 2001
From: David Widmann <david.widmann@it.uu.se>
Date: Fri, 11 Feb 2022 19:12:55 +0000
Subject: [PATCH] Fix `hasmissing` dispatches (#368) (#369)

Fixes #368.
---
 Project.toml     |  2 +-
 src/compiler.jl  |  7 ++++---
 test/compiler.jl | 14 ++++++++++++++
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/Project.toml b/Project.toml
index df3a621de..223032d63 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "DynamicPPL"
 uuid = "366bfd00-2699-11ea-058f-f148b4cae6d8"
-version = "0.17.4"
+version = "0.17.5"
 
 [deps]
 AbstractMCMC = "80f14c24-f653-4e6a-9b94-39d6b0f70001"
diff --git a/src/compiler.jl b/src/compiler.jl
index b9c7eead9..e851dd310 100644
--- a/src/compiler.jl
+++ b/src/compiler.jl
@@ -546,9 +546,10 @@ function make_returns_explicit!(body::Expr)
 end
 
 const FloatOrArrayType = Type{<:Union{AbstractFloat,AbstractArray}}
-hasmissing(T::Type{<:AbstractArray{TA}}) where {TA<:AbstractArray} = hasmissing(TA)
-hasmissing(T::Type{<:AbstractArray{>:Missing}}) = true
-hasmissing(T::Type) = false
+hasmissing(::Type) = false
+hasmissing(::Type{>:Missing}) = true
+hasmissing(::Type{<:AbstractArray{TA}}) where {TA} = hasmissing(TA)
+hasmissing(::Type{Union{}}) = false # issue #368
 
 """
     build_output(modelinfo, linenumbernode)
diff --git a/test/compiler.jl b/test/compiler.jl
index 9dc81ff16..4b1530f11 100644
--- a/test/compiler.jl
+++ b/test/compiler.jl
@@ -588,4 +588,18 @@ end
         @model outer() = @submodel x = inner()
         @test outer()() isa Real
     end
+
+    @testset "issue #368: hasmissing dispatch" begin
+        @test !DynamicPPL.hasmissing(typeof(Union{}[]))
+
+        # (nested) arrays with `Missing` eltypes
+        @test DynamicPPL.hasmissing(Vector{Union{Missing,Float64}})
+        @test DynamicPPL.hasmissing(Matrix{Union{Missing,Real}})
+        @test DynamicPPL.hasmissing(Vector{Matrix{Union{Missing,Float32}}})
+
+        # no `Missing`
+        @test !DynamicPPL.hasmissing(Vector{Float64})
+        @test !DynamicPPL.hasmissing(Matrix{Real})
+        @test !DynamicPPL.hasmissing(Vector{Matrix{Float32}})
+    end
 end