Integrate the Google Test framework.

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "uavcan"]
 	path = src/lib/uavcan
 	url = git://github.com/pavel-kirienko/uavcan.git
+[submodule "unittests/gtest"]
+	path = unittests/gtest
+	url = https://github.com/sjwilks/gtest.git

unittests/Makefile

@@ -3,7 +3,44 @@ CC=g++
 CFLAGS=-I. -I../src/modules -I ../src/include -I../src/drivers \
 	-I../src -I../src/lib -D__EXPORT="" -Dnullptr="0" -lm
 
-all: mixer_test sbus2_test autodeclination_test st24_test sf0x_test
+# Points to the root of Google Test, relative to where this file is.
+# Remember to tweak this if you move this file.
+GTEST_DIR = gtest
+
+# Flags passed to the preprocessor.
+# Set Google Test's header directory as a system directory, such that
+# the compiler doesn't generate warnings in Google Test headers.
+CFLAGS += -isystem $(GTEST_DIR)/include
+
+# All Google Test headers.  Usually you shouldn't change this
+# definition.
+GTEST_HEADERS = $(GTEST_DIR)/include/gtest/*.h \
+                $(GTEST_DIR)/include/gtest/internal/*.h
+
+# Usually you shouldn't tweak such internal variables, indicated by a
+# trailing _.
+GTEST_SRCS_ = $(GTEST_DIR)/src/*.cc $(GTEST_DIR)/src/*.h $(GTEST_HEADERS)
+
+# For simplicity and to avoid depending on Google Test's
+# implementation details, the dependencies specified below are
+# conservative and not optimized.  This is fine as Google Test
+# compiles fast and for ordinary users its source rarely changes.
+gtest-all.o: $(GTEST_SRCS_)
+	$(CC) $(CFLAGS) -I$(GTEST_DIR) -c \
+            $(GTEST_DIR)/src/gtest-all.cc
+
+gtest_main.o: $(GTEST_SRCS_)
+	$(CC) $(CFLAGS) -I$(GTEST_DIR) -c \
+            $(GTEST_DIR)/src/gtest_main.cc
+
+gtest.a: gtest-all.o
+	$(AR) $(ARFLAGS) $@ $^
+
+gtest_main.a: gtest-all.o gtest_main.o
+	$(AR) $(ARFLAGS) $@ $^
+
+
+all: sample_unittest mixer_test sbus2_test autodeclination_test st24_test sf0x_test
 
 MIXER_FILES=../src/systemcmds/tests/test_mixer.cpp \
 		../src/systemcmds/tests/test_conv.cpp \
@@ -33,6 +70,20 @@ AUTODECLINATION_FILES= ../src/lib/geo_lookup/geo_mag_declination.c \
 		hrt.cpp \
 		autodeclination_test.cpp
 
+# Builds a sample test. A test should link with either gtest.a or
+# gtest_main.a, depending on whether it defines its own main()
+# function.
+sample.o: sample.cc sample.h $(GTEST_HEADERS)
+	$(CC) $(CFLAGS) -c sample.cc
+
+sample_unittest.o: sample_unittest.cc \
+                     sample.h $(GTEST_HEADERS)
+	$(CC) $(CFLAGS) -c sample_unittest.cc
+
+sample_unittest: sample.o sample_unittest.o gtest_main.a
+	$(CC) $(CFLAGS) $^ -o $@
+
+
 mixer_test: $(MIXER_FILES)
 	$(CC) -o mixer_test $(MIXER_FILES) $(CFLAGS)
 
@@ -57,4 +108,4 @@ unittests: clean mixer_test sbus2_test sf0x_test autodeclination_test st24_test
 
 .PHONY: clean
 clean:
-	rm -f $(ODIR)/*.o *~ core $(INCDIR)/*~ mixer_test sbus2_test autodeclination_test st24_test sf0x_test
+	rm -f gtest.a gtest_main.a *.o $(ODIR)/*.o *~ core $(INCDIR)/*~ sample_unittest mixer_test sbus2_test autodeclination_test st24_test sf0x_test

unittests/gtest

@@ -0,0 +1 @@
+Subproject commit cdef6e4ce097f953445446e8da4cb8bb68478bc5

unittests/sample.cc

@@ -0,0 +1,68 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+//
+// Author: wan@google.com (Zhanyong Wan)
+
+#include "sample.h"
+
+// Returns n! (the factorial of n).  For negative n, n! is defined to be 1.
+int Factorial(int n) {
+  int result = 1;
+  for (int i = 1; i <= n; i++) {
+    result *= i;
+  }
+
+  return result;
+}
+
+// Returns true iff n is a prime number.
+bool IsPrime(int n) {
+  // Trivial case 1: small numbers
+  if (n <= 1) return false;
+
+  // Trivial case 2: even numbers
+  if (n % 2 == 0) return n == 2;
+
+  // Now, we have that n is odd and n >= 3.
+
+  // Try to divide n by every odd number i, starting from 3
+  for (int i = 3; ; i += 2) {
+    // We only have to try i up to the squre root of n
+    if (i > n/i) break;
+
+    // Now, we have i <= n/i < n.
+    // If n is divisible by i, n is not prime.
+    if (n % i == 0) return false;
+  }
+
+  // n has no integer factor in the range (1, n), and thus is prime.
+  return true;
+}

unittests/sample.h

@@ -0,0 +1,43 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+//
+// Author: wan@google.com (Zhanyong Wan)
+
+#ifndef GTEST_SAMPLES_SAMPLE1_H_
+#define GTEST_SAMPLES_SAMPLE1_H_
+
+// Returns n! (the factorial of n).  For negative n, n! is defined to be 1.
+int Factorial(int n);
+
+// Returns true iff n is a prime number.
+bool IsPrime(int n);
+
+#endif  // GTEST_SAMPLES_SAMPLE1_H_

unittests/sample_unittest.cc

@@ -0,0 +1,153 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+//
+// Author: wan@google.com (Zhanyong Wan)
+
+
+// This sample shows how to write a simple unit test for a function,
+// using Google C++ testing framework.
+//
+// Writing a unit test using Google C++ testing framework is easy as 1-2-3:
+
+
+// Step 1. Include necessary header files such that the stuff your
+// test logic needs is declared.
+//
+// Don't forget gtest.h, which declares the testing framework.
+
+#include <limits.h>
+#include "sample.h"
+#include "gtest/gtest.h"
+
+
+// Step 2. Use the TEST macro to define your tests.
+//
+// TEST has two parameters: the test case name and the test name.
+// After using the macro, you should define your test logic between a
+// pair of braces.  You can use a bunch of macros to indicate the
+// success or failure of a test.  EXPECT_TRUE and EXPECT_EQ are
+// examples of such macros.  For a complete list, see gtest.h.
+//
+// <TechnicalDetails>
+//
+// In Google Test, tests are grouped into test cases.  This is how we
+// keep test code organized.  You should put logically related tests
+// into the same test case.
+//
+// The test case name and the test name should both be valid C++
+// identifiers.  And you should not use underscore (_) in the names.
+//
+// Google Test guarantees that each test you define is run exactly
+// once, but it makes no guarantee on the order the tests are
+// executed.  Therefore, you should write your tests in such a way
+// that their results don't depend on their order.
+//
+// </TechnicalDetails>
+
+
+// Tests Factorial().
+
+// Tests factorial of negative numbers.
+TEST(FactorialTest, Negative) {
+  // This test is named "Negative", and belongs to the "FactorialTest"
+  // test case.
+  EXPECT_EQ(1, Factorial(-5));
+  EXPECT_EQ(1, Factorial(-1));
+  EXPECT_GT(Factorial(-10), 0);
+
+  // <TechnicalDetails>
+  //
+  // EXPECT_EQ(expected, actual) is the same as
+  //
+  //   EXPECT_TRUE((expected) == (actual))
+  //
+  // except that it will print both the expected value and the actual
+  // value when the assertion fails.  This is very helpful for
+  // debugging.  Therefore in this case EXPECT_EQ is preferred.
+  //
+  // On the other hand, EXPECT_TRUE accepts any Boolean expression,
+  // and is thus more general.
+  //
+  // </TechnicalDetails>
+}
+
+// Tests factorial of 0.
+TEST(FactorialTest, Zero) {
+  EXPECT_EQ(1, Factorial(0));
+}
+
+// Tests factorial of positive numbers.
+TEST(FactorialTest, Positive) {
+  EXPECT_EQ(1, Factorial(1));
+  EXPECT_EQ(2, Factorial(2));
+  EXPECT_EQ(6, Factorial(3));
+  EXPECT_EQ(40320, Factorial(8));
+}
+
+
+// Tests IsPrime()
+
+// Tests negative input.
+TEST(IsPrimeTest, Negative) {
+  // This test belongs to the IsPrimeTest test case.
+
+  EXPECT_FALSE(IsPrime(-1));
+  EXPECT_FALSE(IsPrime(-2));
+  EXPECT_FALSE(IsPrime(INT_MIN));
+}
+
+// Tests some trivial cases.
+TEST(IsPrimeTest, Trivial) {
+  EXPECT_FALSE(IsPrime(0));
+  EXPECT_FALSE(IsPrime(1));
+  EXPECT_TRUE(IsPrime(2));
+  EXPECT_TRUE(IsPrime(3));
+}
+
+// Tests positive input.
+TEST(IsPrimeTest, Positive) {
+  EXPECT_FALSE(IsPrime(4));
+  EXPECT_TRUE(IsPrime(5));
+  EXPECT_FALSE(IsPrime(6));
+  EXPECT_TRUE(IsPrime(23));
+}
+
+// Step 3. Call RUN_ALL_TESTS() in main().
+//
+// We do this by linking in src/gtest_main.cc file, which consists of
+// a main() function which calls RUN_ALL_TESTS() for us.
+//
+// This runs all the tests you've defined, prints the result, and
+// returns 0 if successful, or 1 otherwise.
+//
+// Did you notice that we didn't register the tests?  The
+// RUN_ALL_TESTS() macro magically knows about all the tests we
+// defined.  Isn't this convenient?