diff --git a/shell/platform/common/cpp/client_wrapper/include/flutter/json_type.h b/shell/platform/common/cpp/client_wrapper/include/flutter/json_type.h
index 476cee7bfb9..24baf1328d6 100644
--- a/shell/platform/common/cpp/client_wrapper/include/flutter/json_type.h
+++ b/shell/platform/common/cpp/client_wrapper/include/flutter/json_type.h
@@ -23,4 +23,4 @@ using JsonValueType = rapidjson::Document;
 using JsonValueType = Json::Value;
 #endif
 
-#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CPP_CLIENT_WRAPPER_INCLUDE_FLUTTER_JSON_TYPE_H_
\ No newline at end of file
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CPP_CLIENT_WRAPPER_INCLUDE_FLUTTER_JSON_TYPE_H_
diff --git a/shell/platform/common/cpp/public/flutter_export.h b/shell/platform/common/cpp/public/flutter_export.h
index 2f380915f95..ed1660c4398 100644
--- a/shell/platform/common/cpp/public/flutter_export.h
+++ b/shell/platform/common/cpp/public/flutter_export.h
@@ -25,4 +25,4 @@
 
 #endif  // FLUTTER_DESKTOP_LIBRARY
 
-#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CPP_PUBLIC_FLUTTER_EXPORT_H_
\ No newline at end of file
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CPP_PUBLIC_FLUTTER_EXPORT_H_
diff --git a/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h b/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h
index 9bd27904b4e..ecc6388af31 100644
--- a/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h
+++ b/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h
@@ -35,4 +35,4 @@
 
 @end
 
-#endif  // SHELL_PLATFORM_DARWIN_MACOS_FRAMEWORK_SOURCE_FLUTTERDARTPROJECT_INTERNAL_H_
\ No newline at end of file
+#endif  // SHELL_PLATFORM_DARWIN_MACOS_FRAMEWORK_SOURCE_FLUTTERDARTPROJECT_INTERNAL_H_
diff --git a/testing/testing.gni b/testing/testing.gni
index 2356f45bfa7..30c6c715518 100644
--- a/testing/testing.gni
+++ b/testing/testing.gni
@@ -20,7 +20,10 @@ template("fixtures_location") {
   assert(defined(invoker.assets_dir), "The assets directory.")
 
   location_path = rebase_path(invoker.assets_dir)
-  location_source = "namespace flutter {namespace testing {const char* GetFixturesPath() {return \"$location_path\";}}}"
+
+  # Array of source lines. We use a list to ensure a trailing newline is
+  # emitted by write_file() to comply with -Wnewline-eof.
+  location_source = [ "namespace flutter {namespace testing {const char* GetFixturesPath() {return \"$location_path\";}}}" ]
   location_source_path = "$target_gen_dir/fixtures_location$target_name.cc"
 
   write_file(location_source_path, location_source)