Issue 3593 - stop sharing v8::Isolate among tests

test/JsEngine.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 170 matching lines @@
 
 TEST(NewJsEngineTest, GlobalPropertyTest)
 {
   AdblockPlus::JsEnginePtr jsEngine(AdblockPlus::JsEngine::New());
   jsEngine->SetGlobalProperty("foo", jsEngine->NewValue("bar"));
   auto foo = jsEngine->Evaluate("foo");
   ASSERT_TRUE(foo.IsString());
   ASSERT_EQ(foo.AsString(), "bar");
 }
 
+TEST(NewJsEngineTest, MemoryLeak_NoCircularReferences)
+{
+  std::weak_ptr<AdblockPlus::JsEngine> weakJsEngine;
+  {
+    weakJsEngine = AdblockPlus::JsEngine::New();
+  }
+  EXPECT_FALSE(weakJsEngine.lock());
+}
+
+#if UINTPTR_MAX == UINT32_MAX // detection of 32-bit platform

[sergei, 2017/05/24 16:22:32]

Although it might seem hacky, on practice it turned out the most reliable
cross-complier way to detect 32 bit platform.

[hub, 2017/05/24 16:31:40]

We could do something like 

#if UINTPTR_MAX == UINT32_MAX // detection of 32-bit platform
TEST(NewJsEngineTest, MemoryLeak_NoLeak)
#else
TEST(NewJsEngineTest, DISABLED_32bitsOnly_MemoryLeak_NoLeak)
#endif

This would make the test disabled, but still compiled, and state in the output
why it is disabled.

[sergei, 2017/05/24 17:05:51]

Since in this case it will still run, so not disabled, I would rather replace
DISABLED by something else, like VALID or even drop it completely,
32bitsOnly_MemoryLeak_NoLeak. I am not sure that it makes sense to rename the
test depending on the platform, so #if ...#endif can be removed. What about
putting it at the end, MemoryLeak_NoLeak_32bitsOnly?
Thoughts?

[hub, 2017/05/24 18:18:07]

According to this, the test will be disabled (build still comnpiled):

https://github.com/google/googletest/blob/master/googletest/docs/V1_7_Advance...

Since we can't really output any message I find that changing the test name
would help, but if you prefer not, it's fine by me.

[sergei, 2017/05/26 10:56:43]

That's a cool feature of gtest I was not aware of. What about the new variant?

+TEST(NewJsEngineTest, MemoryLeak_NoLeak)
+{
+  static_assert(sizeof(intptr_t) == 4, "It should be 32bit platform");
+  // v8::Isolate by default requires 32MB (depends on platform), so if there is
+  // a memory leak than we will run out of memory on 32 bit platform because it
+  // will allocate 32000 MB which is less than 2GB where it reaches out of
+  // memory. Even on android where it allocates initially 16MB, the test still
+  // makes sense.
+  for (int i = 0; i < 1000; ++i)
+  {
+    AdblockPlus::JsEngine::New();
+  }
+}
+#endif