1 files changed, 36 insertions, 0 deletions
diff --git a/tests/gtests/blenlib/BLI_disjoint_set_test.cc b/tests/gtests/blenlib/BLI_disjoint_set_test.cc
new file mode 100644
index 00000000000..30503954c62
--- /dev/null
+++ b/tests/gtests/blenlib/BLI_disjoint_set_test.cc
@@ -0,0 +1,36 @@
+/* Apache License, Version 2.0 */
+
+#include "BLI_disjoint_set.hh"
+#include "BLI_strict_flags.h"
+
+#include "testing/testing.h"
+
+namespace blender {
+
+TEST(disjoint_set, Test)
+{
+  DisjointSet disjoint_set(6);
+  EXPECT_FALSE(disjoint_set.in_same_set(1, 2));
+  EXPECT_FALSE(disjoint_set.in_same_set(5, 3));
+  EXPECT_TRUE(disjoint_set.in_same_set(2, 2));
+  EXPECT_EQ(disjoint_set.find_root(3), 3u);
+
+  disjoint_set.join(1, 2);
+
+  EXPECT_TRUE(disjoint_set.in_same_set(1, 2));
+  EXPECT_FALSE(disjoint_set.in_same_set(0, 1));
+
+  disjoint_set.join(3, 4);
+
+  EXPECT_FALSE(disjoint_set.in_same_set(2, 3));
+  EXPECT_TRUE(disjoint_set.in_same_set(3, 4));
+
+  disjoint_set.join(1, 4);
+
+  EXPECT_TRUE(disjoint_set.in_same_set(1, 4));
+  EXPECT_TRUE(disjoint_set.in_same_set(1, 3));
+  EXPECT_TRUE(disjoint_set.in_same_set(2, 4));
+  EXPECT_FALSE(disjoint_set.in_same_set(0, 4));
+}
+
+}  // namespace blender