From 4df63b1809a4df446ca7d8b5c2b75380aa3cf15f Mon Sep 17 00:00:00 2001
From: Eric Rahm <erahm@mozilla.com>
Date: Mon, 9 Oct 2017 13:33:16 -0700
Subject: [PATCH] Bug 1403083 - Part 2: Test conditionaly enabling string
 functions. r=froydnj

--HG--
extra : rebase_source : 01e852a2cf86a71fd1842fc852f1c2cdecb67b7b
---
 xpcom/tests/gtest/TestStrings.cpp | 40 +++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/xpcom/tests/gtest/TestStrings.cpp b/xpcom/tests/gtest/TestStrings.cpp
index d28f53e2b8a0..45c63ce7e2f9 100644
--- a/xpcom/tests/gtest/TestStrings.cpp
+++ b/xpcom/tests/gtest/TestStrings.cpp
@@ -26,6 +26,46 @@ void test_assign_helper(const nsACString& in, nsACString &_retval)
   _retval = in;
 }
 
+// Simple helper struct to test if conditionally enabled string functions are
+// working.
+template <typename T>
+struct EnableTest
+{
+  template <typename Q = T, typename EnableIfChar16 = mozilla::Char16OnlyT<Q>>
+  bool IsChar16() { return true; }
+
+  template <typename Q = T, typename EnableIfChar = mozilla::CharOnlyT<Q>>
+  bool IsChar16(int dummy = 42) { return false; }
+
+  template <typename Q = T, typename EnableIfChar16 = mozilla::Char16OnlyT<Q>>
+  bool IsChar() { return false; }
+
+  template <typename Q = T, typename EnableIfChar = mozilla::CharOnlyT<Q>>
+  bool IsChar(int dummy = 42) { return true; }
+};
+
+TEST(Strings, IsChar)
+{
+  EnableTest<char> charTest;
+  EXPECT_TRUE(charTest.IsChar());
+  EXPECT_FALSE(charTest.IsChar16());
+
+  EnableTest<char16_t> char16Test;
+  EXPECT_TRUE(char16Test.IsChar16());
+  EXPECT_FALSE(char16Test.IsChar());
+
+#ifdef COMPILATION_FAILURE_TEST
+  nsAutoCString a_ctest;
+  nsAutoString a_test;
+
+  a_ctest.AssignLiteral("hello");
+  // This should cause a compilation failure.
+  a_ctest.AssignLiteral(u"hello");
+  a_test.AssignLiteral(u"hello");
+  a_test.AssignLiteral("hello");
+#endif
+}
+
 TEST(Strings, assign)
 {
   nsCString result;