Add unit tests for cancer stick castle library

- Fix the minor issues with the initial library implementation.
- Add unit tests to cover basic scenarios.

Bug: none
Change-Id: Ibf28b4e20f74792fce2fe11d4780fd375a4ad3a3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/183343
Commit-Queue: Lahiru Ginnaliya Gamathige <glahiru@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32122}

BUILD.gn

@@ -538,6 +538,7 @@ if (rtc_include_tests) {
       "call:fake_network_pipe_unittests",
       "p2p:libstunprober_unittests",
       "p2p:rtc_p2p_unittests",
+      "rtc_base:cancer_stick_castle_unittests",
       "rtc_base:function_unittest",
       "rtc_base:rtc_base_approved_unittests",
       "rtc_base:rtc_base_unittests",

rtc_base/BUILD.gn

@@ -1070,6 +1070,19 @@ rtc_library("testclient") {
   ]
 }
 
+rtc_library("cancer_stick_castle_unittests") {
+  testonly = true
+
+  sources = [ "cancer_stick_castle_unittest.cc" ]
+  deps = [
+    ":cancer_stick_castle",
+    ":gunit_helpers",
+    ":rtc_base",
+    "../api:function_view",
+    "../test:test_support",
+  ]
+}
+
 rtc_library("rtc_base_tests_utils") {
   testonly = true
   sources = [

rtc_base/cancer_stick_castle.h

@@ -56,7 +56,7 @@ class CancerStickCastle {
     receivers_.AddReceiver(
         UntypedFunction::Create<void(ArgT...)>(std::forward<F>(f)));
   }
-  void Send(ArgT... args) {
+  void Send(ArgT&&... args) {
     receivers_.Foreach([&](UntypedFunction& f) {
       f.Call<void(ArgT...)>(std::forward<ArgT>(args)...);
     });

rtc_base/cancer_stick_castle_unittest.cc

@@ -0,0 +1,162 @@
+/*
+ *  Copyright 2020 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include <string>
+#include <type_traits>
+
+#include "api/function_view.h"
+#include "rtc_base/bind.h"
+#include "rtc_base/cancer_stick_castle.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+TEST(CancerStickCastle, NoRecieverSingleMessageTest) {
+  CancerStickCastle<std::string> c;
+
+  c.Send("message");
+}
+
+TEST(CancerStickCastle, MultipleParameterMessageTest) {
+  CancerStickCastle<const std::string&, std::string, std::string&&, int, int*,
+                    std::string&>
+      c;
+  std::string str = "messege";
+  int i = 10;
+
+  c.Send(str, "message1", "message0", 123, &i, str);
+}
+
+TEST(CancerStickCastle, NoParameterMessageTest) {
+  CancerStickCastle<> c;
+
+  c.Send();
+}
+
+TEST(CancerStickCastle, ReferenceTest) {
+  CancerStickCastle<int&> c;
+  int index = 1;
+
+  c.AddReceiver([](int& index) { index++; });
+  c.Send(index);
+
+  EXPECT_EQ(index, 2);
+}
+
+TEST(CancerStickCastle, ConstReferenceTest) {
+  CancerStickCastle<int&> c;
+  int i = 0;
+  int index = 1;
+
+  c.AddReceiver([&i](const int& index) { i = index; });
+  c.Send(index);
+
+  EXPECT_EQ(i, 1);
+}
+
+TEST(CancerStickCastle, PointerTest) {
+  CancerStickCastle<int*> c;
+  int index = 1;
+
+  c.AddReceiver([](int* index) { (*index)++; });
+  c.Send(&index);
+
+  EXPECT_EQ(index, 2);
+}
+
+void PlusOne(int& a) {
+  a++;
+}
+
+TEST(CancerStickCastle, FunctionPtrTest) {
+  CancerStickCastle<int&> c;
+  int index = 1;
+
+  c.AddReceiver(PlusOne);
+  c.Send(index);
+
+  EXPECT_EQ(index, 2);
+}
+
+struct LargeNonTrivial {
+  int a[17];
+
+  LargeNonTrivial() = default;
+  LargeNonTrivial(LargeNonTrivial&& m) {}
+  ~LargeNonTrivial() = default;
+
+  void operator()(int& a) { a = 1; }
+};
+
+TEST(CancerStickCastle, LargeNonTrivialTest) {
+  CancerStickCastle<int&> c;
+  int i = 0;
+  static_assert(sizeof(LargeNonTrivial) > 16, "");
+  c.AddReceiver(LargeNonTrivial());
+  c.Send(i);
+
+  EXPECT_EQ(i, 1);
+}
+
+/* sizeof(LargeTrivial) = 20bytes which is greater than
+ * the size check (16bytes) of the CSC library */
+struct LargeTrivial {
+  int a[17];
+  void operator()(int& x) { x = 1; }
+};
+
+TEST(CancerStickCastle, LargeTrivial) {
+  CancerStickCastle<int&> c;
+  LargeTrivial lt;
+  int i = 0;
+
+  static_assert(sizeof(lt) > 16, "");
+  c.AddReceiver(lt);
+  c.Send(i);
+
+  EXPECT_EQ(i, 1);
+}
+
+struct OnlyNonTriviallyConstructible {
+  OnlyNonTriviallyConstructible() = default;
+  OnlyNonTriviallyConstructible(OnlyNonTriviallyConstructible&& m) {}
+
+  void operator()(int& a) { a = 1; }
+};
+
+TEST(CancerStickCastle, OnlyNonTriviallyMoveConstructible) {
+  CancerStickCastle<int&> c;
+  int i = 0;
+
+  c.AddReceiver(OnlyNonTriviallyConstructible());
+  c.Send(i);
+
+  EXPECT_EQ(i, 1);
+}
+
+TEST(CancerStickCastle, MultipleReceiverSendTest) {
+  CancerStickCastle<int&> c;
+  std::function<void(int&)> plus = PlusOne;
+  int index = 1;
+
+  c.AddReceiver(plus);
+  c.AddReceiver([](int& i) { i--; });
+  c.AddReceiver(plus);
+  c.AddReceiver(plus);
+  c.Send(index);
+  c.Send(index);
+
+  EXPECT_EQ(index, 5);
+}
+// todo(glahiru): Add a test case to catch some error for Karl's first fix
+// todo(glahiru): Add a test for rtc::Bind
+// which used the following code in the Send
+}  // namespace
+}  // namespace webrtc