tests: clean up use of random device

lonvia · lonvia · commit 0b6f4c2d4a83 · 2019-12-29T10:02:46.000+01:00
Use a fixed seed to make the results reproducable.
Choose a distribution range that ensures that all points are
valid latitudes/longitudes.
diff --git a/tests/test-output-gazetteer.cpp b/tests/test-output-gazetteer.cpp
@@ -7,8 +7,10 @@
 
 static testing::db::import_t db;
 
-static std::random_device dev;
-static std::mt19937 rng(dev());
+// Use a random device with a fixed seed. We don't really care about
+// the quality of random numbers here, we just need to generate valid
+// OSM test data. The fixed seed ensures that the results are reproducible.
+static std::mt19937_64 rng(47382);
 
 class node_opl_t
 {
@@ -72,7 +74,7 @@ class way_opl_t
         unsigned const num_nodes = intdist(rng);
 
         // compute the start point, all points afterwards are relative
-        std::uniform_real_distribution<double> dist{-90, 89.99};
+        std::uniform_real_distribution<double> dist{-89.9, 89.9};
         double x = 2 * dist(rng);
         double y = dist(rng);
 
@@ -138,7 +140,7 @@ class relation_opl_t
     osmid_t make_nodes()
     {
         // compute a centre points and compute four corners from this
-        std::uniform_real_distribution<double> dist{-90, 89.99};
+        std::uniform_real_distribution<double> dist{-89.9, 89.9};
         double const x = 2 * dist(rng);
         double const y = dist(rng);
 
