feat: initial model of GoogleTest-based performance testing

Provides [0, X) and (X, Y) matchers for average time.
Uses std::chrono, with duration suffix printer support.

TODO: Support for a complexity argument
TODO: Don't create a unique suite for each test case in TEST_PERF

include/testing/performance_test.h

@@ -0,0 +1,202 @@
+//
+//  performance_test.h
+//
+//  Created by Sam Jaffe on 11/4/23.
+//  Copyright © 2020 Sam Jaffe. All rights reserved.
+//
+
+#pragma once
+#define CONCAT2(A, B) A##B
+#define CONCAT(A, B) CONCAT2(A, B)
+
+#include <chrono>
+
+#include <testing/xcode_gtest_helper.h>
+
+#if __cplusplus >= 202002L
+#elif defined(__has_include) && __has_include(<date/date.h>)
+#include <date/date.h>
+using date::operator<<;
+#else
+namespace std::chrono {
+template <typename Rep, typename Period>
+ostream &operator<<(ostream &os, duration<Rep, Period> const & dur) {
+  os << dur.count();
+  if (Period::den == 1) {
+    switch (Period::num) {
+    case 1: return os << 's';
+    case 60: return os << 'm';
+    case 3600: return os << 'h';
+    case 86400: return os << 'd';
+    }
+  } else if (Period::num == 1) {
+    switch (Period::den) {
+    case 1000: return os << "ms";
+    case 1000'000: return os << "\u00B5s";
+    case 1000'000'000: return os << "ns";
+    }
+  }
+  return os << Period::num << '/' << Period::den << 's';
+}
+}
+#endif
+
+#define PERF_TEST_CLASS(name) CONCAT(PerfTest, name)
+
+/**
+ * Example code using TEST_PERF:
+ *
+ * TEST_PERF(MyClassTest, Initialization, 50ms) {
+ *   ... setup input variables ...
+ *   MyClass object(...);
+ *   (void) object;
+ * }
+ *
+ * void ComplexTest::SetUp() {
+ *   ... setup input variables as above to keep out of perf test ...
+ *   object = MyClass(...);
+ * }
+ *
+ * TEST_PERF_F(ComplexTest, ExpensiveFunction, 100ms) {
+ *   this->object.ExpensiveFunction();
+ * }
+ */
+#define TEST_PERF(test_suite_name, test_name, limit)                        \
+    PERFORMANCE_FIXTURE_IMPL(test_suite_name, test_name, testing::Test, limit)
+
+#define TEST_PERF_F(test_fixture, test_name, limit)          \
+    PERFORMANCE_FIXTURE_IMPL(test_suite_name, test_name, test_suite_name, limit)
+
+#define PERFORMANCE_TEST_CLASS(suite, case) CONCAT(suite, CONCAT(_, case))
+#define PERFORMANCE_FIXTURE_IMPL(suite, case, parent, limit) \
+    class PERFORMANCE_TEST_CLASS(suite, case) : public parent { \
+    protected: \
+      void TestImpl(); \
+    }; \
+    TEST_F(PERFORMANCE_TEST_CLASS(suite, case), Performance) { \
+      EXPECT_PERFORMANCE(TestImpl(), limit); \
+    } \
+    void PERFORMANCE_TEST_CLASS(suite, case)::TestImpl()
+
+/**
+ * Example code using EXPECT_PERFORMANCE:
+ * using std::literals::chrono_literals::operator""ms;
+ *
+ * TEST(MyClassPerfTest, Initialization) {
+ *   EXPECT_PERFORMANCE(MyClass(...), testing::Le(50ms));
+ * }
+ *
+ * TEST(MyClassPerfTest, ExpensiveFunction) {
+ *   MyClass object(...);
+ *   EXPECT_PERFORMANCE(object.ExpensiveFunction(), testing::Le(100ms));
+ * }
+ */
+#define EXPECT_PERFORMANCE(expression, matcher)     \
+  EXPECT_PERFORMANCE_IMPL(expression, matcher, 1UL)
+
+namespace testing::perf {
+using Clock = std::chrono::high_resolution_clock;
+
+template <typename> struct DurationImpl {
+  using type = std::chrono::nanoseconds;
+};
+
+template <typename Rep, typename Ratio>
+struct DurationImpl<std::chrono::duration<Rep, Ratio>> {
+  using type = std::chrono::duration<Rep, Ratio>;
+};
+
+template <typename Duration>
+struct PerformanceTestDuration {
+  Clock::duration average() const { return (ticks.back() - ticks.front()) / size(); }
+  operator Duration() const {
+    return std::chrono::duration_cast<Duration>(ticks.back() - ticks.front());
+  }
+
+  size_t size() const { return ticks.size() - 1; }
+  Duration operator()(size_t i = 0) const {
+    return std::chrono::duration_cast<Duration>(ticks.at(i + 1) - ticks.at(i));
+  }
+  void lap() { ticks.push_back(Clock::now()); }
+  
+  std::vector<Clock::time_point> ticks{};
+};
+
+template <typename Duration>
+void PrintTo(PerformanceTestDuration<Duration> const &ptd, std::ostream *os) {
+  (*os) << "duration: " << static_cast<Duration>(ptd);
+  if (size_t const n = ptd.size(); n > 1) {
+    [[maybe_unused]] int const digits = n == 1 ? 1 : std::log10(n - 1) + 1;
+    double X = 0, X2 = 0;
+    
+    for (size_t i = 0; i < n; ++i) {
+      auto d = ptd(i);
+      X += d.count();
+      X2 += std::pow(d.count(), 2);
+#     if defined(PERFORMANCE_TEST_PRINT_LAPS)
+        (*os) << "\nlap " << std::setw(digits) << i << ": " << d;
+#     endif
+    }
+    
+    long long E = X / n;
+    long long S = std::sqrt(X2 / n - std::pow(X / n, 2));
+    (*os) << "\naverage: " << Duration(E);
+    (*os) << "\nstd.dev: " << Duration(S);
+  }
+}
+
+template <typename> struct first_type {
+  using type = Clock::duration;
+};
+
+template <template <typename...> class Template, typename Arg0, typename Arg1, typename... Args>
+struct first_type<Template<Arg0, Arg1, Args...>> {
+  using type = std::decay_t<Arg1>;
+};
+
+template <typename T> using first_type_t = typename first_type<T>::type;
+
+MATCHER_P(FasterThan, limit, "is < " + testing::PrintToString(limit)) {
+  return arg.average() < limit;
+}
+
+MATCHER_P2(BetweenTimes, low, high,
+          "is between " + testing::PrintToString(low) + " and " +
+           testing::PrintToString(high)) {
+  return arg.average() < high && arg.average() > low;
+}
+
+MATCHER_P2(OnAverage, n, m,
+           (n == 1 ? "" : "on average ") + DescribeMatcher<arg_type>(m)) {
+  return testing::Matcher<arg_type>(m).MatchAndExplain(arg, result_listener);
+}
+}
+
+#define EXPECT_PERFORMANCE_IMPL(expression, matcher, n_reps) \
+  do {                                                       \
+    using namespace testing::perf;                           \
+    using namespace std::literals::chrono_literals;          \
+                                                             \
+    using duration_t = first_type_t<decltype(matcher)>;      \
+    PerformanceTestDuration<duration_t> duration;            \
+                                                             \
+    for (size_t i = 0; i < n_reps; ++i) {                    \
+      duration.lap();                                        \
+      (void) expression;                                     \
+    }                                                        \
+    duration.lap();                                          \
+                                                             \
+    EXPECT_THAT(duration, OnAverage(n_reps, matcher));       \
+  } while (false)
+
+
+#define TEST_PERF_IMPL(test_suite_name, test_name, parent_class, limit) \
+  class PERF_TEST_CLASS(test_suite_name) : public parent_class {        \
+  protected:                                                            \
+    void TestImpl();                                                    \
+  };                                                                    \
+  TEST_F(PERF_TEST_CLASS(test_suite_name), test_name) {                 \
+    EXPECT_PERFORMANCE(TestImpl(), limit);                              \
+  }                                                                     \
+  void PERF_TEST_CLASS(test_suite_name)::TestImpl()
+

include/testing/xcode_gtest_helper.h

@@ -0,0 +1,44 @@
+//
+//  xcode_gtest_helper.h
+//
+//  Created by Sam Jaffe on 11/25/20.
+//  Copyright © 2020 Sam Jaffe. All rights reserved.
+//
+
+#pragma once
+
+#if __has_include("printers.h")
+#  include "printers.h"
+#endif
+
+#if defined(__APPLE__)
+#  pragma clang diagnostic push
+#  pragma clang diagnostic ignored "-Wquoted-include-in-framework-header"
+#  pragma clang diagnostic ignored "-Wcomma"
+
+#  include <gmock/gmock.h>
+#  include <gtest/gtest.h>
+
+#  pragma clang diagnostic pop
+#else
+#  include <gmock/gmock.h>
+#  include <gtest/gtest.h>
+#endif
+
+#if defined(TARGET_OS_OSX)
+// This is a hack to allow XCode to properly display failures when running
+// unit tests.
+#  undef EXPECT_THAT
+#  define EXPECT_THAT ASSERT_THAT
+#  undef EXPECT_THROW
+#  define EXPECT_THROW ASSERT_THROW
+#  undef EXPECT_ANY_THROW
+#  define EXPECT_ANY_THROW ASSERT_ANY_THROW
+#  undef EXPECT_NO_THROW
+#  define EXPECT_NO_THROW ASSERT_NO_THROW
+#  undef EXPECT_TRUE
+#  define EXPECT_TRUE ASSERT_TRUE
+#  undef EXPECT_FALSE
+#  define EXPECT_FALSE ASSERT_FALSE
+
+#endif

test-helpers.xcodeproj/project.pbxproj

@@ -0,0 +1,517 @@
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+}

test/test_helper_test.cxx

@@ -0,0 +1,26 @@
+//
+//  test_helper_test.cxx
+//  test-helpers-test
+//
+//  Created by Sam Jaffe on 1/27/24.
+//
+
+#include "testing/xcode_gtest_helper.h"
+#include "testing/performance_test.h"
+
+#include <thread>
+
+using namespace std::literals::chrono_literals;
+using testing::Not;
+
+TEST_PERF(PerformanceMetaTest, Fast, FasterThan(1us)) {
+  strlen("HELLO, WORLD");
+}
+
+TEST_PERF(PerformanceMetaTest, Slow, Not(FasterThan(1us))) {
+  std::this_thread::sleep_for(1us);
+}
+
+TEST_PERF(PerformanceMetaTest, Right, BetweenTimes(1ns, 1us)) {
+  strlen("HELLO, WORLD");
+}