fix: swap direction of edges in update_functions_to_interaction_graph

Author: ReubenJ

src/qualitative_networks.jl

@@ -239,10 +239,10 @@ function update_functions_to_interaction_graph(
         graph[entity] = Entity{Int}(fn, domain)
     end
 
-    for (e1, f) in zip(entities, update_functions)
+    for (dst, f) in zip(entities, update_functions)
         input_entities = collect(Leaves(f))
-        for e2 in input_entities
-            add_edge!(graph, e1, e2)
+        for src in input_entities
+            add_edge!(graph, src, dst)
         end
     end
 

test/qn_test.jl

@@ -22,6 +22,19 @@ end
     @test issubset(Set(constants), Set(g.rules))
 end
 
+@testitem "QN Graph Correctness" begin
+    entities = [:a, :b, :c]
+    target_fns = Union{Expr,Integer,Symbol}[:(-c), :a, :b]
+    domains = [0:2 for _ = 1:3]
+
+    qn = QN(entities, target_fns, domains)
+    g = get_graph(qn)
+
+    @test haskey(g, :c, :a)
+    @test haskey(g, :a, :b)
+    @test haskey(g, :b, :c)
+end
+
 @testitem "QN Sampling" setup = [RandomSetup, ExampleQN] begin
     using Graphs: ne, nv
     graph = get_graph(qn)