Merge 4ac8c39200d36e332ae3a26373bb7f54059619a4 into 7140cd416cecd7462a8aae488024abeee55598e4

PiperOrigin-RevId: 925686474
Change-Id: I7b5d7e82dc8618d6914844446fa260468b947ece

docs/gmock_cook_book.md

@@ -3386,30 +3386,6 @@ With this definition, the above assertion will give a better message:
     Actual: 27 (the remainder is 6)
 ```
 
-#### Using EXPECT_ Statements in Matchers
-
-You can also use `EXPECT_...` statements inside custom matcher definitions. In
-many cases, this allows you to write your matcher more concisely while still
-providing an informative error message. For example:
-
-```cpp
-MATCHER(IsDivisibleBy7, "") {
-  const auto remainder = arg % 7;
-  EXPECT_EQ(remainder, 0);
-  return true;
-}
-```
-
-If you write a test that includes the line `EXPECT_THAT(27, IsDivisibleBy7());`,
-you will get an error something like the following:
-
-```shell
-Expected equality of these values:
-  remainder
-    Which is: 6
-  0
-```
-
 #### `MatchAndExplain`
 
 You should let `MatchAndExplain()` print *any additional information* that can
@@ -3429,6 +3405,66 @@ the value of `(arg % 7) == 0` can be implicitly converted to a `bool`. In the
 `arg_type` will be `int`; if it takes an `unsigned long`, `arg_type` will be
 `unsigned long`; and so on.
 
+#### Anti-pattern: Using EXPECT_ Statements in Matchers
+
+Using `EXPECT_...` statements inside custom matcher definitions is an
+**anti-pattern** and should be avoided.
+
+While it might appear to write matchers more concisely and generate informative
+messages, this pattern has critical issues:
+
+1.  **Negation Breakage (`Not`):** If wrapped in `Not(IsDivisibleBy7())`,
+    evaluating it still triggers the internal `EXPECT_EQ`, registering a test
+    failure on the runner even when the overall assertion is expected to
+    succeed.
+2.  **Composition / Container Breakage (`AnyOf`, `AllOf`, `Contains`):** When
+    composed or used inside container matchers, elements that are expected
+    mismatches will trigger the internal `EXPECT_` and register spurious
+    failures.
+3.  **ASSERT_* compilation errors:** `ASSERT_*` macros use `return;` to abort
+    from a void function. Since matchers return `bool`, using `ASSERT_` inside
+    them triggers a compilation error.
+4.  **Purity Violations:** Matchers must be functionally pure (side-effect
+    free), whereas registering global failures is a major side effect.
+5.  **Line Number Confusion:** Failure reports point to the matcher's definition
+    line rather than the calling `EXPECT_THAT`
+    line.
+
+##### The Anti-Pattern
+
+```cpp
+// Anti-pattern: Do not do this!
+MATCHER(IsDivisibleBy7, "") {
+  const auto remainder = arg % 7;
+  EXPECT_EQ(remainder, 0);  // Spurious failures if negated/composed!
+  return true;
+}
+```
+
+##### The Correct Solution
+
+To write concise matchers that delegate to other matchers and safely propagate
+the mismatch explanation, use **`::testing::ExplainMatchResult`** instead,
+passing it the sub-matcher, the value to check, and the `result_listener`:
+
+```cpp
+MATCHER(IsDivisibleBy7, "") {
+  const auto remainder = arg % 7;
+  return ::testing::ExplainMatchResult(::testing::Eq(0), remainder,
+                                       result_listener);
+}
+```
+
+If you write a test that includes the line:
+
+```cpp
+EXPECT_THAT(28, Not(IsDivisibleBy7()));
+```
+
+it will correctly report the mismatch, properly point to the `EXPECT_THAT` line
+number, and support negation (`Not`) and composition (`AllOf`, `AnyOf`, etc.)
+without registering spurious failures.
+
 ### Writing New Parameterized Matchers Quickly
 
 Sometimes you'll want to define a matcher that has parameters. For that you can

googlemock/include/gmock/gmock-spec-builders.h

@@ -1957,6 +1957,11 @@ struct SignatureOf<R(Args...)> {
   using type = R(Args...);
 };
 
+template <typename R, typename... Args>
+struct SignatureOf<R(Args...) const> {
+  using type = R(Args...);
+};
+
 template <template <typename> class C, typename F>
 struct SignatureOf<C<F>,
                    typename std::enable_if<std::is_function<F>::value>::type>

googlemock/test/gmock-function-mocker_test.cc

@@ -942,6 +942,15 @@ static constexpr bool IsMockFunctionTemplateArgumentDeducedTo(
 
 }  // namespace
 
+// Like std::add_const, but for function types.
+template <typename F>
+struct AddConstToFunction;
+
+template <typename R, typename... Args>
+struct AddConstToFunction<R(Args...)> {
+  using type = R(Args...) const;
+};
+
 template <typename F>
 class MockMethodMockFunctionSignatureTest : public Test {};
 
@@ -953,25 +962,69 @@ TYPED_TEST_SUITE(MockMethodMockFunctionSignatureTest,
 
 TYPED_TEST(MockMethodMockFunctionSignatureTest,
            IsMockFunctionTemplateArgumentDeducedForRawSignature) {
-  using Argument = TypeParam;
-  MockFunction<Argument> foo;
-  EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+  // Non-const
+  {
+    using Argument = TypeParam;
+    MockFunction<Argument> foo;
+    EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+  }
+
+  // Const
+  {
+    using Argument = typename AddConstToFunction<TypeParam>::type;
+    MockFunction<Argument> foo;
+    EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+  }
 }
 
 TYPED_TEST(MockMethodMockFunctionSignatureTest,
            IsMockFunctionTemplateArgumentDeducedForStdFunction) {
-  using Argument = std::function<TypeParam>;
-  MockFunction<Argument> foo;
-  EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+  // Non-const
+  {
+    using Argument = std::function<TypeParam>;
+    MockFunction<Argument> foo;
+    EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+  }
+
+// As of 2026-05 MSVC doesn't know how to deal with this, providing pages of
+// inscrutable errors about std::_Get_function_impl. But this is fine, since
+// std::function<R(Args...) const> doesn't apply the const qualifier correctly
+// anyway.
+#if !defined(_MSC_VER)
+
+  // Const
+  {
+    using Argument =
+        std::function<typename AddConstToFunction<TypeParam>::type>;
+
+    MockFunction<Argument> foo;
+    EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+  }
+
+#endif
 }
 
 TYPED_TEST(
     MockMethodMockFunctionSignatureTest,
     IsMockFunctionCallMethodSignatureTheSameForRawSignatureAndStdFunction) {
-  using ForRawSignature = decltype(&MockFunction<TypeParam>::Call);
-  using ForStdFunction =
-      decltype(&MockFunction<std::function<TypeParam>>::Call);
-  EXPECT_TRUE((std::is_same<ForRawSignature, ForStdFunction>::value));
+  // Non-const
+  {
+    using ForRawSignature = decltype(&MockFunction<TypeParam>::Call);
+    using ForStdFunction =
+        decltype(&MockFunction<std::function<TypeParam>>::Call);
+    EXPECT_TRUE((std::is_same<ForRawSignature, ForStdFunction>::value));
+  }
+
+  // Const
+  {
+    using ConstTypeParam = typename AddConstToFunction<TypeParam>::type;
+    using ForRawSignature = decltype(&MockFunction<ConstTypeParam>::Call);
+
+    using ForStdFunction =
+        decltype(&MockFunction<std::function<ConstTypeParam>>::Call);
+
+    EXPECT_TRUE((std::is_same<ForRawSignature, ForStdFunction>::value));
+  }
 }
 
 template <typename F>

googletest/include/gtest/gtest-message.h

@@ -129,7 +129,7 @@ class GTEST_API_ Message {
                               int>::type = 0
 #endif  // GTEST_HAS_ABSL
       >
-  inline Message& operator<<(const T& val) {
+  Message& operator<<(const T& val) {
         // Some libraries overload << for STL containers.  These
     // overloads are defined in the global namespace instead of ::std.
     //
@@ -155,7 +155,7 @@ class GTEST_API_ Message {
   template <typename T,
             typename std::enable_if<absl::HasAbslStringify<T>::value,  // NOLINT
                                     int>::type = 0>
-  inline Message& operator<<(const T& val) {
+  Message& operator<<(const T& val) {
     // ::operator<< is needed here for a similar reason as with the non-Abseil
     // version above
     using ::operator<<;

googletest/include/gtest/gtest.h

@@ -1023,6 +1023,27 @@ class [[nodiscard]] EmptyTestEventListener : public TestEventListener {
   void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
 };
 
+class XmlUnitTestResultPrinter : public EmptyTestEventListener {
+ public:
+#if GTEST_HAS_FILE_SYSTEM
+  XmlUnitTestResultPrinter(const char* output_file);
+#endif  // GTEST_HAS_FILE_SYSTEM
+
+  XmlUnitTestResultPrinter(std::ostream* output_stream);
+
+  XmlUnitTestResultPrinter(const XmlUnitTestResultPrinter&) = delete;
+  XmlUnitTestResultPrinter& operator=(const XmlUnitTestResultPrinter&) = delete;
+
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void ListTestsMatchingFilter(const std::vector<TestSuite*>& test_suites);
+
+ private:
+#if GTEST_HAS_FILE_SYSTEM
+  const std::string output_file_;
+#endif  // GTEST_HAS_FILE_SYSTEM
+  std::ostream* output_stream_;
+};
+
 // TestEventListeners lets users add listeners to track events in Google Test.
 class GTEST_API_ [[nodiscard]] TestEventListeners {
  public:

googletest/include/gtest/internal/gtest-death-test-internal.h

@@ -229,7 +229,8 @@ GTEST_API_ bool ExitedUnsuccessfully(int exit_status);
       goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__);                        \
     }                                                                          \
     if (gtest_dt != nullptr) {                                                 \
-      std::unique_ptr< ::testing::internal::DeathTest> gtest_dt_ptr(gtest_dt); \
+      const std::unique_ptr< ::testing::internal::DeathTest> gtest_dt_ptr(     \
+          gtest_dt);                                                           \
       switch (gtest_dt->AssumeRole()) {                                        \
         case ::testing::internal::DeathTest::OVERSEE_TEST:                     \
           if (!gtest_dt->Passed(predicate(gtest_dt->Wait()))) {                \

googletest/src/gtest.cc

@@ -2427,7 +2427,6 @@ static std::vector<std::string> GetReservedAttributesForElement(
   return std::vector<std::string>();
 }
 
-#if GTEST_HAS_FILE_SYSTEM
 // TODO(jdesprez): Merge the two getReserved attributes once skip is improved
 // This function is only used when file systems are enabled.
 static std::vector<std::string> GetReservedOutputAttributesForElement(
@@ -2444,7 +2443,6 @@ static std::vector<std::string> GetReservedOutputAttributesForElement(
   // This code is unreachable but some compilers may not realizes that.
   return std::vector<std::string>();
 }
-#endif
 
 static std::string FormatWordList(const std::vector<std::string>& words) {
   Message word_list;
@@ -3974,14 +3972,10 @@ void TestEventRepeater::OnTestIterationEnd(const UnitTest& unit_test,
 
 // End TestEventRepeater
 
-#if GTEST_HAS_FILE_SYSTEM
 // This class generates an XML output file.
 class XmlUnitTestResultPrinter : public EmptyTestEventListener {
  public:
-  explicit XmlUnitTestResultPrinter(const char* output_file);
-
-  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
-  void ListTestsMatchingFilter(const std::vector<TestSuite*>& test_suites);
+  XmlUnitTestResultPrinter() = delete;
 
   // Prints an XML summary of all unit tests.
   static void PrintXmlTestsList(std::ostream* stream,
@@ -4064,40 +4058,9 @@ class XmlUnitTestResultPrinter : public EmptyTestEventListener {
                                       const TestResult& result,
                                       const std::string& indent);
 
-  // The output file.
-  const std::string output_file_;
-
-  XmlUnitTestResultPrinter(const XmlUnitTestResultPrinter&) = delete;
-  XmlUnitTestResultPrinter& operator=(const XmlUnitTestResultPrinter&) = delete;
+  friend ::testing::XmlUnitTestResultPrinter;
 };
 
-// Creates a new XmlUnitTestResultPrinter.
-XmlUnitTestResultPrinter::XmlUnitTestResultPrinter(const char* output_file)
-    : output_file_(output_file) {
-  if (output_file_.empty()) {
-    GTEST_LOG_(FATAL) << "XML output file may not be null";
-  }
-}
-
-// Called after the unit test ends.
-void XmlUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
-                                                  int /*iteration*/) {
-  FILE* xmlout = OpenFileForWriting(output_file_);
-  std::stringstream stream;
-  PrintXmlUnitTest(&stream, unit_test);
-  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
-  fclose(xmlout);
-}
-
-void XmlUnitTestResultPrinter::ListTestsMatchingFilter(
-    const std::vector<TestSuite*>& test_suites) {
-  FILE* xmlout = OpenFileForWriting(output_file_);
-  std::stringstream stream;
-  PrintXmlTestsList(&stream, test_suites);
-  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
-  fclose(xmlout);
-}
-
 // Returns an XML-escaped copy of the input string str.  If is_attribute
 // is true, the text is meant to appear as an attribute value, and
 // normalizable whitespace is preserved by replacing it with character
@@ -4529,7 +4492,6 @@ void XmlUnitTestResultPrinter::OutputXmlTestProperties(
 }
 
 // End XmlUnitTestResultPrinter
-#endif  // GTEST_HAS_FILE_SYSTEM
 
 #if GTEST_HAS_FILE_SYSTEM
 // This class generates an JSON output file.
@@ -5273,6 +5235,69 @@ void TestEventListeners::SuppressEventForwarding(bool suppress) {
   repeater_->set_forwarding_enabled(!suppress);
 }
 
+#if GTEST_HAS_FILE_SYSTEM
+// Creates a new XmlUnitTestResultPrinter.
+XmlUnitTestResultPrinter::XmlUnitTestResultPrinter(const char* output_file)
+    : output_file_(output_file) {
+  if (output_file_.empty()) {
+    GTEST_LOG_(FATAL) << "XML output file may not be null";
+  }
+}
+#endif  // GTEST_HAS_FILE_SYSTEM
+
+// Creates a new XmlUnitTestResultPrinter.
+XmlUnitTestResultPrinter::XmlUnitTestResultPrinter(std::ostream* output_stream)
+    : output_stream_(output_stream) {
+  if (!output_stream->good()) {
+    GTEST_LOG_(FATAL) << "XML output is not good";
+  }
+}
+
+// Called after the unit test ends.
+void XmlUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                  int /*iteration*/) {
+#if GTEST_HAS_FILE_SYSTEM
+  FILE* xmlout = 0;
+  if(!output_stream_) {
+      xmlout = internal::OpenFileForWriting(output_file_);
+      output_stream_ = new std::stringstream;
+  }
+#endif  // GTEST_HAS_FILE_SYSTEM
+
+  internal::XmlUnitTestResultPrinter::PrintXmlUnitTest(output_stream_, unit_test);
+
+#if GTEST_HAS_FILE_SYSTEM
+  if(xmlout) {
+      fprintf(xmlout, "%s", internal::StringStreamToString(static_cast<std::stringstream*>(output_stream_)).c_str());
+      fclose(xmlout);
+      delete output_stream_;
+      output_stream_ = 0;
+  }
+#endif  // GTEST_HAS_FILE_SYSTEM
+}
+
+void XmlUnitTestResultPrinter::ListTestsMatchingFilter(
+      const std::vector<TestSuite*>& test_suites) {
+#if GTEST_HAS_FILE_SYSTEM
+  FILE* xmlout = 0;
+  if(!output_stream_) {
+      xmlout = internal::OpenFileForWriting(output_file_);
+      output_stream_ = new std::stringstream;
+  }
+#endif  // GTEST_HAS_FILE_SYSTEM
+
+  internal::XmlUnitTestResultPrinter::PrintXmlTestsList(output_stream_, test_suites);
+
+#if GTEST_HAS_FILE_SYSTEM
+  if(xmlout) {
+      fprintf(xmlout, "%s", internal::StringStreamToString(static_cast<std::stringstream*>(output_stream_)).c_str());
+      fclose(xmlout);
+      delete output_stream_;
+      output_stream_ = 0;
+  }
+#endif  // GTEST_HAS_FILE_SYSTEM
+}
+
 // class UnitTest
 
 // Gets the singleton UnitTest object.  The first time this method is
@@ -5774,7 +5799,7 @@ void UnitTestImpl::ConfigureXmlOutput() {
   const std::string& output_format = UnitTestOptions::GetOutputFormat();
 #if GTEST_HAS_FILE_SYSTEM
   if (output_format == "xml") {
-    listeners()->SetDefaultXmlGenerator(new XmlUnitTestResultPrinter(
+    listeners()->SetDefaultXmlGenerator(new ::testing::XmlUnitTestResultPrinter(
         UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
   } else if (output_format == "json") {
     listeners()->SetDefaultXmlGenerator(new JsonUnitTestResultPrinter(
@@ -6425,9 +6450,7 @@ void UnitTestImpl::ListTestsMatchingFilter() {
         OpenFileForWriting(UnitTestOptions::GetAbsolutePathToOutputFile());
     std::stringstream stream;
     if (output_format == "xml") {
-      XmlUnitTestResultPrinter(
-          UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
-          .PrintXmlTestsList(&stream, test_suites_);
+      XmlUnitTestResultPrinter::PrintXmlTestsList(&stream, test_suites_);
     } else if (output_format == "json") {
       JsonUnitTestResultPrinter(
           UnitTestOptions::GetAbsolutePathToOutputFile().c_str())