Add Unity-based unit test infrastructure (Phase 1: 117 tests passing)

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Co-authored-by: welcor <357770+welcor@users.noreply.github.com>

tests/test_random.c

@@ -0,0 +1,156 @@
+/**
+ * @file test_random.c
+ * Unit tests for src/random.c and the random-number helpers in src/utils.c
+ * (rand_number, dice).
+ */
+
+#include "unity.h"
+
+#include "conf.h"
+#include "sysdep.h"
+#include "structs.h"
+#include "utils.h"
+
+extern FILE *logfile;
+
+void setUp(void)    { logfile = stderr; }
+void tearDown(void) { logfile = NULL; }
+
+/* =========================================================
+ * circle_srandom / circle_random — deterministic sequence
+ *
+ * The Park-Miller generator with seed s produces:
+ *   G(s) = (16807 * s) mod 2147483647
+ * Precomputed for seed=1:
+ *   call 1 → 16807
+ *   call 2 → 282475249
+ *   call 3 → 1622136673
+ * ========================================================= */
+
+void test_circle_random_deterministic_first(void)
+{
+    circle_srandom(1);
+    TEST_ASSERT_EQUAL_UINT32(16807UL, circle_random());
+}
+
+void test_circle_random_deterministic_second(void)
+{
+    circle_srandom(1);
+    circle_random();                           /* discard first */
+    TEST_ASSERT_EQUAL_UINT32(282475249UL, circle_random());
+}
+
+void test_circle_random_deterministic_third(void)
+{
+    circle_srandom(1);
+    circle_random();
+    circle_random();
+    TEST_ASSERT_EQUAL_UINT32(1622650073UL, circle_random());
+}
+
+void test_circle_random_same_seed_same_sequence(void)
+{
+    circle_srandom(42);
+    unsigned long a = circle_random();
+    unsigned long b = circle_random();
+
+    circle_srandom(42);
+    TEST_ASSERT_EQUAL_UINT32(a, circle_random());
+    TEST_ASSERT_EQUAL_UINT32(b, circle_random());
+}
+
+/* =========================================================
+ * rand_number — result always in [from, to]
+ * ========================================================= */
+
+void test_rand_number_in_range(void)
+{
+    int i;
+    circle_srandom(12345);
+    for (i = 0; i < 200; i++) {
+        int v = rand_number(1, 10);
+        TEST_ASSERT_GREATER_OR_EQUAL_INT(1, v);
+        TEST_ASSERT_LESS_OR_EQUAL_INT(10, v);
+    }
+}
+
+void test_rand_number_same_low_high(void)
+{
+    int i;
+    circle_srandom(1);
+    for (i = 0; i < 50; i++)
+        TEST_ASSERT_EQUAL_INT(7, rand_number(7, 7));
+}
+
+void test_rand_number_inverted_args(void)
+{
+    /* rand_number logs SYSERR and swaps; result must still be in [1,10] */
+    int i;
+    circle_srandom(1);
+    for (i = 0; i < 50; i++) {
+        int v = rand_number(10, 1);
+        TEST_ASSERT_GREATER_OR_EQUAL_INT(1, v);
+        TEST_ASSERT_LESS_OR_EQUAL_INT(10, v);
+    }
+}
+
+/* =========================================================
+ * dice — num dice each of size sides
+ * ========================================================= */
+
+void test_dice_zero_dice(void)
+{
+    circle_srandom(1);
+    TEST_ASSERT_EQUAL_INT(0, dice(0, 6));
+}
+
+void test_dice_zero_sides(void)
+{
+    circle_srandom(1);
+    TEST_ASSERT_EQUAL_INT(0, dice(3, 0));
+}
+
+void test_dice_result_in_range(void)
+{
+    int i;
+    circle_srandom(99);
+    for (i = 0; i < 200; i++) {
+        int v = dice(2, 6);
+        TEST_ASSERT_GREATER_OR_EQUAL_INT(2, v);
+        TEST_ASSERT_LESS_OR_EQUAL_INT(12, v);
+    }
+}
+
+void test_dice_one_die_one_side(void)
+{
+    circle_srandom(1);
+    TEST_ASSERT_EQUAL_INT(1, dice(1, 1));
+}
+
+/* =========================================================
+ * main
+ * ========================================================= */
+
+int main(void)
+{
+    UNITY_BEGIN();
+
+    /* circle_srandom / circle_random */
+    RUN_TEST(test_circle_random_deterministic_first);
+    RUN_TEST(test_circle_random_deterministic_second);
+    RUN_TEST(test_circle_random_deterministic_third);
+    RUN_TEST(test_circle_random_same_seed_same_sequence);
+
+    /* rand_number */
+    RUN_TEST(test_rand_number_in_range);
+    RUN_TEST(test_rand_number_same_low_high);
+    RUN_TEST(test_rand_number_inverted_args);
+
+    /* dice */
+    RUN_TEST(test_dice_zero_dice);
+    RUN_TEST(test_dice_zero_sides);
+    RUN_TEST(test_dice_result_in_range);
+    RUN_TEST(test_dice_one_die_one_side);
+
+    return UNITY_END();
+}