From cc01f10967266efca65fda06d10c20dde60b5eb0 Mon Sep 17 00:00:00 2001
From: rusefi <rusefillc@gmail.com>
Date: Wed, 30 Aug 2023 23:39:09 -0400
Subject: [PATCH] 
 https://github.com/rusefi/rusefi/commit/13c496b79bebfa5941092ef6b5b5f3a5e97e3332
 moving test as well

---
 util/test/test_wraparound.cpp | 69 +++++++++++++++++++++++++++++++++++
 util/util.mk                  |  1 +
 2 files changed, 70 insertions(+)
 create mode 100644 util/test/test_wraparound.cpp

diff --git a/util/test/test_wraparound.cpp b/util/test/test_wraparound.cpp
new file mode 100644
index 0000000..ce25a18
--- /dev/null
+++ b/util/test/test_wraparound.cpp
@@ -0,0 +1,69 @@
+#include <gtest/gtest.h>
+#include <rusefi/rusefi_time_types.h>
+#include <rusefi/rusefi_time_wraparound.h>
+
+TEST(util, WrapAround62) {
+	// Random test
+	{
+		WrapAround62 t;
+		uint32_t source = 0;
+		uint64_t actual = 0;
+
+		// Test random progression, positive and negative.
+		uint32_t seed = time(NULL);
+		printf("Testing with seed 0x%08x\n", seed);
+		srand(seed);
+		for (unsigned i = 0; i < 10000; i++) {
+			int32_t delta = rand();
+			if (delta < 0) {
+				delta = ~delta;
+			}
+			delta -= RAND_MAX >> 1;
+
+			// Cap negative test
+			if (delta < 0 && -delta > actual) {
+				delta = -actual;
+			}
+
+			source += delta;
+			actual += delta;
+
+			uint64_t next = t.update(source);
+			EXPECT_EQ(actual, next);
+		}
+	}
+
+	// More pointed test for expected edge conditions
+	{
+		WrapAround62 t;
+
+		EXPECT_EQ(t.update(0x03453455), 0x003453455LL);
+		EXPECT_EQ(t.update(0x42342323), 0x042342323LL);
+		EXPECT_EQ(t.update(0x84356345), 0x084356345LL);
+		EXPECT_EQ(t.update(0x42342323), 0x042342323LL);
+		EXPECT_EQ(t.update(0x84356345), 0x084356345LL);
+		EXPECT_EQ(t.update(0xC5656565), 0x0C5656565LL);
+		EXPECT_EQ(t.update(0x01122112), 0x101122112LL); // Wrap around!
+		EXPECT_EQ(t.update(0xC5656565), 0x0C5656565LL);
+		EXPECT_EQ(t.update(0x84356345), 0x084356345LL);
+		EXPECT_EQ(t.update(0xC5656565), 0x0C5656565LL);
+		EXPECT_EQ(t.update(0x01122112), 0x101122112LL); // Wrap around!
+		EXPECT_EQ(t.update(0x42342323), 0x142342323LL);
+		EXPECT_EQ(t.update(0x84356345), 0x184356345LL);
+		EXPECT_EQ(t.update(0x42342323), 0x142342323LL);
+		EXPECT_EQ(t.update(0x84356345), 0x184356345LL);
+		EXPECT_EQ(t.update(0xC5656565), 0x1C5656565LL);
+		EXPECT_EQ(t.update(0x01122112), 0x201122112LL); // Wrap around!
+		EXPECT_EQ(t.update(0xC5656565), 0x1C5656565LL);
+		EXPECT_EQ(t.update(0x84356345), 0x184356345LL);
+		EXPECT_EQ(t.update(0xC5656565), 0x1C5656565LL);
+		EXPECT_EQ(t.update(0x01122112), 0x201122112LL); // Wrap around!
+		EXPECT_EQ(t.update(0xC5656565), 0x1C5656565LL);
+		EXPECT_EQ(t.update(0x84356345), 0x184356345LL);
+		EXPECT_EQ(t.update(0x42342323), 0x142342323LL);
+		EXPECT_EQ(t.update(0x01122112), 0x101122112LL);
+		EXPECT_EQ(t.update(0x84356345), 0x084356345LL);
+		EXPECT_EQ(t.update(0x42342323), 0x042342323LL);
+		EXPECT_EQ(t.update(0x03453455), 0x003453455LL);
+	}
+}
diff --git a/util/util.mk b/util/util.mk
index 0ce559a..b94a131 100644
--- a/util/util.mk
+++ b/util/util.mk
@@ -14,5 +14,6 @@ RUSEFI_LIB_CPP_TEST += \
 	$(RUSEFI_LIB)/util/test/test_fragments.cpp \
 	$(RUSEFI_LIB)/util/test/test_interpolation.cpp \
 	$(RUSEFI_LIB)/util/test/test_scaled.cpp \
+	$(RUSEFI_LIB)/util/test/test_wraparound.cpp \
 	$(RUSEFI_LIB)/util/test/test_math.cpp \