From 0dc20489b9487436b8bef3cfb4a6d7ef58a03775 Mon Sep 17 00:00:00 2001
From: Alexandre Bouchard <bouchard@stat.ubc.ca>
Date: Tue, 13 Aug 2024 11:17:53 -0700
Subject: [PATCH] Fix #263

---
 src/explorers/SliceSampler.jl |  1 +
 test/test_slice_sampler.jl    | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/src/explorers/SliceSampler.jl b/src/explorers/SliceSampler.jl
index 878169795..1a940e732 100644
--- a/src/explorers/SliceSampler.jl
+++ b/src/explorers/SliceSampler.jl
@@ -134,6 +134,7 @@ end
 
 # handle integers separately
 function initialize_slice_endpoints(current::T, width, rng) where {T<:Integer}
+    @assert isinteger(width) "for integer variables, the width should be an integer. Got: $width"
     width = ceil(T, width)
     L = current - rand(rng, 0:width)
     R = L + width
diff --git a/test/test_slice_sampler.jl b/test/test_slice_sampler.jl
index 89461c094..274a0d2b2 100644
--- a/test/test_slice_sampler.jl
+++ b/test/test_slice_sampler.jl
@@ -104,3 +104,17 @@ end
 @testset "SliceSampler" begin
     test_slice_sampler()
 end
+
+
+DynamicPPL.@model function test()
+    p ~ Categorical(0.1*ones(10))
+end
+
+
+@testset "Bad width" begin 
+    test_target = TuringLogPotential(test())
+    inputs = Inputs(target = test_target,
+                explorer = SliceSampler(w = 0.1, p = 20, n_passes = 1, max_iter = 1_024)
+                )
+    @test_throws "AssertionError: for integer variables, the width should be an integer. Got: 0.1" pt = pigeons(inputs)
+end
\ No newline at end of file