msvc fix

third_party/CMakeLists.txt

@@ -31,6 +31,28 @@ if(NOT ${GTEST_FOUND})
     OVERRIDE_FIND_PACKAGE)
   fetchcontent_makeavailable(GTest)
 endif()
+if(MSVC)
+  # ------------------------------------------------------------------------------
+  # gtest MSVC fix
+  # ------------------------------------------------------------------------------
+  # For some reason, googletest has include path issues when built with MSVC.
+  # Specifically, this seems like some incorrect assumptions about include paths
+  # inside the gmock project.
+  # We can fix this by injecting the include paths here.
+  function(fix_gtest_include TARGET)
+    target_include_directories(
+      ${TARGET}
+      PUBLIC $<BUILD_INTERFACE:${gtest_SOURCE_DIR}>
+              $<BUILD_INTERFACE:${gtest_SOURCE_DIR}/include>
+              $<BUILD_INTERFACE:${gtest_SOURCE_DIR}/googletest>
+              $<BUILD_INTERFACE:${gtest_SOURCE_DIR}/googletest/include>
+              $<INSTALL_INTERFACE:include/${TARGET}>)
+  endfunction()
+  set(gtest_erroneous_targets gmock gmock_main)
+  foreach(target ${gtest_erroneous_targets})
+    fix_gtest_include(${target})
+  endforeach()
+endif()
 
 set(PREVIOUS_BUILD_TESTING ${BUILD_TESTING})
 set(BUILD_TESTING OFF)