From 065bafb23d02edbd99f5bfafe803d8ad75398263 Mon Sep 17 00:00:00 2001
From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Thu, 10 Nov 2016 14:02:58 +0100
Subject: [PATCH] test for random [sic] utility methods

---
 src/rand/GaloisLFSR.hpp     |  2 +
 tst/rand/GaloisLFSRTest.cpp | 84 +++++++++++++++++++++++++++++++++++++
 tst/rand/GaloisLFSRTest.hpp | 48 +++++++++++++++++++++
 3 files changed, 134 insertions(+)
 create mode 100644 tst/rand/GaloisLFSRTest.cpp
 create mode 100644 tst/rand/GaloisLFSRTest.hpp

diff --git a/src/rand/GaloisLFSR.hpp b/src/rand/GaloisLFSR.hpp
index 81652d8..0011739 100644
--- a/src/rand/GaloisLFSR.hpp
+++ b/src/rand/GaloisLFSR.hpp
@@ -63,10 +63,12 @@ public:
 
 	template<class Container>
 	typename Container::reference From(Container &c) {
+		assert(c.size() > 0);
 		return c[Next<typename Container::size_type>() % c.size()];
 	}
 	template<class Container>
 	typename Container::const_reference From(const Container &c) {
+		assert(c.size() > 0);
 		return c[Next<typename Container::size_type>() % c.size()];
 	}
 
diff --git a/tst/rand/GaloisLFSRTest.cpp b/tst/rand/GaloisLFSRTest.cpp
new file mode 100644
index 0000000..05c4f4e
--- /dev/null
+++ b/tst/rand/GaloisLFSRTest.cpp
@@ -0,0 +1,84 @@
+#include "GaloisLFSRTest.hpp"
+
+#include "rand/GaloisLFSR.hpp"
+
+#include <algorithm>
+#include <sstream>
+
+CPPUNIT_TEST_SUITE_REGISTRATION(blank::test::GaloisLFSRTest);
+
+using namespace std;
+
+
+namespace blank {
+namespace test {
+
+void GaloisLFSRTest::setUp() {
+
+}
+
+void GaloisLFSRTest::tearDown() {
+
+}
+
+void GaloisLFSRTest::testFloatNorm() {
+	GaloisLFSR random(4);
+	for (int i = 0; i < 64; ++i) {
+		float value = random.SNorm();
+		AssertBetween(
+			"random signed normal float",
+			-1.0f, 1.0f, value);
+	}
+	for (int i = 0; i < 64; ++i) {
+		float value = random.UNorm();
+		AssertBetween(
+			"random unsigned normal float",
+			0.0f, 1.0f, value);
+	}
+}
+
+void GaloisLFSRTest::testFromContainer() {
+	GaloisLFSR random(5);
+	const vector<int> container({ 1, 2, 3, 4, 5 });
+	for (int i = 0; i < 64; ++i) {
+		int element = random.From(container);
+		AssertContains(
+			"random element from container",
+			container, element);
+	}
+}
+
+void GaloisLFSRTest::AssertBetween(
+	string message,
+	float minimum,
+	float maximum,
+	float actual
+) {
+	stringstream msg;
+	msg << message << ": " << actual << " not in ["
+		<< minimum << ',' << maximum << ']';
+	CPPUNIT_ASSERT_MESSAGE(
+		msg.str(),
+		minimum <= actual && actual <= maximum);
+
+}
+
+void GaloisLFSRTest::AssertContains(
+	string message,
+	const vector<int> &container,
+	int element
+) {
+	stringstream msg;
+	msg << message << ": " << element << " not in { ";
+	for (int i : container) {
+		msg << i << ' ';
+	}
+	msg << '}';
+	CPPUNIT_ASSERT_MESSAGE(
+		msg.str(),
+		find(container.begin(), container.end(), element) != container.end());
+
+}
+
+}
+}
diff --git a/tst/rand/GaloisLFSRTest.hpp b/tst/rand/GaloisLFSRTest.hpp
new file mode 100644
index 0000000..3669ab4
--- /dev/null
+++ b/tst/rand/GaloisLFSRTest.hpp
@@ -0,0 +1,48 @@
+#ifndef BLANK_TEST_RAND_GALOISLFSRTEST_HPP
+#define BLANK_TEST_RAND_GALOISLFSRTEST_HPP
+
+#include <cppunit/extensions/HelperMacros.h>
+
+#include <string>
+#include <vector>
+
+
+namespace blank {
+
+namespace test {
+
+class GaloisLFSRTest
+: public CppUnit::TestFixture {
+
+CPPUNIT_TEST_SUITE(GaloisLFSRTest);
+
+CPPUNIT_TEST(testFloatNorm);
+CPPUNIT_TEST(testFromContainer);
+
+CPPUNIT_TEST_SUITE_END();
+
+public:
+	void setUp();
+	void tearDown();
+
+	void testFloatNorm();
+	void testFromContainer();
+
+	/// check if value is in range [minimum,maximum]
+	static void AssertBetween(
+		std::string message,
+		float minimum,
+		float maximum,
+		float actual);
+
+	static void AssertContains(
+		std::string message,
+		const std::vector<int> &container,
+		int element);
+
+};
+
+}
+}
+
+#endif
-- 
2.39.2