added unit test for rtree mapping

test/src/rtree_mapper.cpp

@@ -0,0 +1,64 @@
+#include "Epatest.hpp"
+
+#include "core/pll/rtree_mapper.hpp"
+
+#include "io/file_io.hpp"
+#include "tree/Tree_Numbers.hpp"
+#include "core/raxml/Model.hpp"
+
+#include <vector>
+#include <string>
+
+using placepair = std::pair<unsigned int, double>;
+
+static void test_placement_mapping( std::string const& tree_file,
+                                    std::vector<placepair> const& utree_placements,
+                                    std::vector<placepair> const& rtree_placements )
+{
+  // buildup
+  pll_utree_t * tree;
+  raxml::Model model;
+
+  rtree_mapper mapper;
+  Tree_Numbers nums;
+  tree = build_tree_from_file( tree_file, nums, mapper );
+
+  assert( utree_placements.size() == rtree_placements.size() );
+
+  for (size_t i = 0; i < utree_placements.size(); ++i) {
+
+    auto const& u_p = utree_placements[i];
+    auto const& r_p = rtree_placements[i];
+
+    // translate
+    unsigned int edge = 0;
+    double distal = -1.0;
+
+    std::tie(edge, distal) = mapper.in_rtree( u_p.first, u_p.second );
+
+    EXPECT_EQ(    r_p.first,  edge );
+    EXPECT_NEAR(  r_p.second, distal, 1e-10 );
+  }
+
+  // teardown
+  pll_utree_destroy(tree, nullptr);
+}
+
+TEST(rtree_mapper, translate_distal)
+{
+  /*  basic idea of this test: init the mapper by different rooted trees
+      for which we know the resulting distal lengths of placements
+  */
+
+  test_placement_mapping(
+    env->tree_file_rooted,
+    { {0, 1.0}, {7, 1.5}, {8, 0.5},   {8, 0.001}, },
+    { {0, 1.0}, {8, 1.5}, {6, 0.52},  {9, 0.001}, }
+  );
+
+  test_placement_mapping(
+    env->tree_file_rooted_2,
+    { {0, 1.34}, {0, 1.345}, {8, 0.5},  {2, 0.001}, },
+    { {0, 1.34}, {9, 0.005}, {8, 0.5},  {2, 0.001}, }
+  );
+}