intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 75 insertions, 0 deletions

diff --git a/util/random/shuffle_ut.cpp b/util/random/shuffle_ut.cpp
new file mode 100644
index 00000000000..87cbae94c00
--- /dev/null
+++ b/util/random/shuffle_ut.cpp
@@ -0,0 +1,75 @@
+#include "fast.h"
+#include "shuffle.h"
+#include "mersenne.h"
+
+#include <library/cpp/testing/unittest/registar.h>
+
+#include <util/generic/ylimits.h>
+
+Y_UNIT_TEST_SUITE(TRandUtilsTest) {
+    template <typename... A>
+    static void TestRange(A&&... args) {
+        TString s0, s1;
+        ShuffleRange(s1, args...);
+        s1 = "0";
+        ShuffleRange(s1, args...);
+        s1 = "01";
+        ShuffleRange(s1, args...);
+        s1 = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+        s0 = s1.copy();
+        ShuffleRange(s1, args...);
+        UNIT_ASSERT(s0 != s1); // if shuffle does work, chances it will fail are 1 to 64!.
+    }
+
+    template <typename... A>
+    static void TestIter(A&&... args) {
+        TString s0, s1;
+
+        auto f = [&]() {
+            auto b = s1.begin();
+            auto e = s1.end();
+
+            Shuffle(b, e, args...);
+        };
+
+        s1 = "0";
+        f();
+
+        s1 = "01";
+        f();
+
+        s1 = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+        s0 = s1.copy();
+        f();
+
+        UNIT_ASSERT(s0 != s1); // if shuffle does work, chances it will fail are 1 to 64!.
+    }
+
+    Y_UNIT_TEST(TestShuffle) {
+        TestRange();
+    }
+
+    Y_UNIT_TEST(TestShuffleMersenne64) {
+        TMersenne<ui64> prng(42);
+
+        TestRange(prng);
+    }
+
+    Y_UNIT_TEST(TestShuffleMersenne32) {
+        TMersenne<ui32> prng(24);
+
+        TestIter(prng);
+    }
+
+    Y_UNIT_TEST(TestShuffleFast32) {
+        TFastRng32 prng(24, 0);
+
+        TestIter(prng);
+    }
+
+    Y_UNIT_TEST(TestShuffleFast64) {
+        TFastRng64 prng(24, 0, 25, 1);
+
+        TestIter(prng);
+    }
+}