test: more complete PRNG unit tests.

test/unit/rand.cpp

@@ -33,7 +33,10 @@ LOLUNIT_FIXTURE(RandTest)
 
         for (int i = 0; i < rolls; ++i)
         {
-            uint32_t r = rand<int>();
+            int32_t r = rand<int32_t>();
+
+            LOLUNIT_ASSERT_GEQUAL(r, 0);
+
             for (int k = 0; k < 31; k++)
             {
                 bits[k] += r & 1;
@@ -44,8 +47,66 @@ LOLUNIT_FIXTURE(RandTest)
         for (int k = 0; k < 31; k++)
         {
             LOLUNIT_SET_CONTEXT(k);
-            LOLUNIT_ASSERT_GREATER(bits[k], rolls / 3);
-            LOLUNIT_ASSERT_LESS(bits[k], rolls * 2 / 3);
+            LOLUNIT_ASSERT_GEQUAL(bits[k], rolls / 3);
+            LOLUNIT_ASSERT_LEQUAL(bits[k], rolls * 2 / 3);
+            LOLUNIT_UNSET_CONTEXT(k);
+        }
+    }
+
+    LOLUNIT_TEST(Int16Bits)
+    {
+        int const rolls = 2000;
+
+        int bits[16];
+        memset(bits, 0, sizeof(bits));
+
+        for (int i = 0; i < rolls; ++i)
+        {
+            int16_t r = rand<int16_t>();
+
+            LOLUNIT_ASSERT_GEQUAL(r, 0);
+
+            for (int k = 0; k < 15; k++)
+            {
+                bits[k] += r & 1;
+                r >>= 1;
+            }
+        }
+
+        for (int k = 0; k < 15; k++)
+        {
+            LOLUNIT_SET_CONTEXT(k);
+            LOLUNIT_ASSERT_GEQUAL(bits[k], rolls / 3);
+            LOLUNIT_ASSERT_LEQUAL(bits[k], rolls * 2 / 3);
+            LOLUNIT_UNSET_CONTEXT(k);
+        }
+    }
+
+    LOLUNIT_TEST(Int8Bits)
+    {
+        int const rolls = 2000;
+
+        int bits[8];
+        memset(bits, 0, sizeof(bits));
+
+        for (int i = 0; i < rolls; ++i)
+        {
+            int8_t r = rand<int8_t>();
+
+            LOLUNIT_ASSERT_GEQUAL(r, 0);
+
+            for (int k = 0; k < 7; k++)
+            {
+                bits[k] += r & 1;
+                r >>= 1;
+            }
+        }
+
+        for (int k = 0; k < 7; k++)
+        {
+            LOLUNIT_SET_CONTEXT(k);
+            LOLUNIT_ASSERT_GEQUAL(bits[k], rolls / 3);
+            LOLUNIT_ASSERT_LEQUAL(bits[k], rolls * 2 / 3);
             LOLUNIT_UNSET_CONTEXT(k);
         }
     }