find cycle in graph

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/modules/graph/test.lua b/tests/modules/graph/test.lua
index cc0e16738..63095be12 100644
--- a/tests/modules/graph/test.lua
+++ b/tests/modules/graph/test.lua
@@ -38,3 +38,19 @@ function test_topological_sort(t)
     end
 end
 
+function test_find_cycle(t)
+    local edges = {
+        {9, 1},
+        {1, 6},
+        {6, 0},
+        {0, 1},
+        {4, 5}
+    }
+    local dag = graph.new(true)
+    for _, e in ipairs(edges) do
+        dag:add_edge(e[1], e[2])
+    end
+    local cycle = dag:find_cycle()
+    t:are_equal(cycle, {1, 6, 0})
+end
+