From 92d0a6f7e2dafe49377669884e665026fc1aa376 Mon Sep 17 00:00:00 2001
From: Vladimir Goncharov <amatanhead@yandex-team.ru>
Date: Tue, 7 Jul 2020 19:09:53 +0300
Subject: [PATCH] Add a test to ensure that the `Throws` matcher only invokes
 its argument once.

---
 googlemock/test/gmock-matchers_test.cc | 30 ++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/googlemock/test/gmock-matchers_test.cc b/googlemock/test/gmock-matchers_test.cc
index cd89d81e0..21ade890f 100644
--- a/googlemock/test/gmock-matchers_test.cc
+++ b/googlemock/test/gmock-matchers_test.cc
@@ -8145,6 +8145,36 @@ TEST(ThrowsTest, DoesNotGenerateDuplicateCatchClauseWarning) {
       Throws<std::exception>());
 }
 
+TEST(ThrowsTest, CallableExecutedExactlyOnce) {
+  size_t a = 0;
+
+  EXPECT_THAT(
+      [&a]() { a++; throw 10; },
+      Throws<int>());
+  EXPECT_EQ(a, 1);
+
+  EXPECT_THAT(
+      [&a]() { a++; throw std::runtime_error("message"); },
+      Throws<std::runtime_error>());
+  EXPECT_EQ(a, 2);
+
+  EXPECT_THAT(
+      [&a]() { a++; throw std::runtime_error("message"); },
+      ThrowsMessage<std::runtime_error>(HasSubstr("message")));
+  EXPECT_EQ(a, 3);
+
+  EXPECT_THAT(
+      [&a]() { a++; throw std::runtime_error("message"); },
+      ThrowsMessageHasSubstr<std::runtime_error>("message"));
+  EXPECT_EQ(a, 4);
+
+  EXPECT_THAT(
+      [&a]() { a++; throw std::runtime_error("message"); },
+      Throws<std::runtime_error>(
+          Property(&std::runtime_error::what, HasSubstr("message"))));
+  EXPECT_EQ(a, 5);
+}
+
 TEST(ThrowsTest, Describe) {
   Matcher<void (*)()> matcher = Throws<std::runtime_error>();
   std::stringstream ss;