Convert some internal functions to take std::string_view

src/api/game/game.cpp

@@ -139,7 +139,7 @@ std::filesystem::path ResolvePluginPath(
 
 std::vector<std::filesystem::path> FindArchives(
     const std::filesystem::path& parentPath,
-    const std::string& archiveFileExtension) {
+    std::string_view archiveFileExtension) {
   if (!std::filesystem::is_directory(parentPath)) {
     return {};
   }

src/api/game/game_cache.cpp

@@ -36,7 +36,7 @@ std::vector<const Plugin*> GameCache::GetPlugins() const {
   return output;
 }
 
-const Plugin* GameCache::GetPlugin(const std::string& pluginName) const {
+const Plugin* GameCache::GetPlugin(std::string_view pluginName) const {
   const auto it = plugins_.find(NormalizeFilename(pluginName));
   if (it != end(plugins_))
     return it->second.get();

src/api/game/game_cache.h

@@ -26,6 +26,7 @@
 #define LOOT_API_GAME_GAME_CACHE
 
 #include <string>
+#include <string_view>
 #include <unordered_map>
 
 #include "api/plugin.h"
@@ -34,7 +35,7 @@ namespace loot {
 class GameCache {
 public:
   std::vector<const Plugin*> GetPlugins() const;
-  const Plugin* GetPlugin(const std::string& pluginName) const;
+  const Plugin* GetPlugin(std::string_view pluginName) const;
   void AddPlugin(Plugin&& plugin);
 
   std::vector<const Plugin*> GetPluginsWithReplacements(

src/api/game/load_order_handler.cpp

@@ -210,7 +210,8 @@ std::filesystem::path LoadOrderHandler::GetActivePluginsFilePath() const {
   return filePath;
 }
 
-std::vector<std::filesystem::path> LoadOrderHandler::GetAdditionalDataPaths() const {
+std::vector<std::filesystem::path> LoadOrderHandler::GetAdditionalDataPaths()
+    const {
   const auto logger = getLogger();
   if (logger) {
     logger->trace("Getting additional data paths.");
@@ -219,7 +220,8 @@ std::vector<std::filesystem::path> LoadOrderHandler::GetAdditionalDataPaths() co
   char** pathArr = nullptr;
   size_t pathArrSize = 0;
 
-  const unsigned int ret = lo_get_additional_plugins_directories(gh_.get(), &pathArr, &pathArrSize);
+  const unsigned int ret =
+      lo_get_additional_plugins_directories(gh_.get(), &pathArr, &pathArrSize);
 
   HandleError("get additional data paths", ret);
 
@@ -288,7 +290,7 @@ void LoadOrderHandler::SetAdditionalDataPaths(
   }
 }
 
-void LoadOrderHandler::HandleError(const std::string& operation,
+void LoadOrderHandler::HandleError(std::string_view operation,
                                    unsigned int returnCode) const {
   if (returnCode == LIBLO_OK || returnCode == LIBLO_WARN_LO_MISMATCH) {
     return;
@@ -298,10 +300,10 @@ void LoadOrderHandler::HandleError(const std::string& operation,
   std::string err;
   lo_get_error_message(&e);
   if (e == nullptr) {
-    err = "libloadorder failed to " + operation +
-          ". Details could not be fetched.";
+    err = fmt::format(
+        "libloadorder failed to {}. Details could not be fetched.", operation);
   } else {
-    err = "libloadorder failed to " + operation + ". Details: " + e;
+    err = fmt::format("libloadorder failed to {}. Details: {}", operation, e);
   }
 
   auto logger = getLogger();

src/api/game/load_order_handler.h

@@ -28,6 +28,7 @@
 #include <filesystem>
 #include <libloadorder.hpp>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include "loot/enum/game_type.h"
@@ -61,7 +62,7 @@ public:
       const std::vector<std::filesystem::path>& dataPaths) const;
 
 private:
-  void HandleError(const std::string& operation, unsigned int returnCode) const;
+  void HandleError(std::string_view operation, unsigned int returnCode) const;
 
   std::unique_ptr<std::remove_pointer<lo_game_handle>::type,
                   decltype(&lo_destroy_handle)>

src/api/helpers/text.cpp

@@ -55,7 +55,7 @@ constexpr const char* pseudosemVersionRegex =
    'v' or 'version:. */
 constexpr const char* digitsVersionRegex = R"((?:^|v|version:\s*)(\d+))";
 
-std::vector<Tag> ExtractBashTags(const std::string& description) {
+std::vector<Tag> ExtractBashTags(std::string_view description) {
   std::vector<Tag> tags;
 
   static constexpr const char* BASH_TAGS_OPENER = "{{BASH:";
@@ -87,7 +87,7 @@ std::vector<Tag> ExtractBashTags(const std::string& description) {
   return tags;
 }
 
-std::optional<std::string> ExtractVersion(const std::string& text) {
+std::optional<std::string> ExtractVersion(std::string_view text) {
   using std::regex;
 
   /* There are a few different version formats that can appear in strings
@@ -102,9 +102,9 @@ std::optional<std::string> ExtractVersion(const std::string& text) {
       regex(digitsVersionRegex, regex::ECMAScript | regex::icase),
   });
 
-  std::smatch what;
+  std::match_results<std::string_view::iterator> what;
   for (const auto& versionRegex : versionRegexes) {
-    if (std::regex_search(text, what, versionRegex)) {
+    if (std::regex_search(text.begin(), text.end(), what, versionRegex)) {
       for (auto it = next(begin(what)); it != end(what); ++it) {
         if (it->str().empty())
           continue;
@@ -135,9 +135,9 @@ int narrow(size_t value) {
   return castValue;
 }
 
-std::wstring ToWinWide(const std::string& str) {
+std::wstring ToWinWide(std::string_view str) {
   const size_t len = MultiByteToWideChar(
-      CP_UTF8, 0, str.c_str(), static_cast<int>(str.length()), 0, 0);
+      CP_UTF8, 0, str.data(), static_cast<int>(str.length()), 0, 0);
 
   if (len == 0) {
     return std::wstring();
@@ -146,7 +146,7 @@ std::wstring ToWinWide(const std::string& str) {
   std::wstring wstr(len, 0);
   MultiByteToWideChar(CP_UTF8,
                       0,
-                      str.c_str(),
+                      str.data(),
                       narrow(str.length()),
                       wstr.data(),
                       narrow(wstr.length()));
@@ -180,7 +180,7 @@ std::string FromWinWide(const std::wstring& wstr) {
 }
 #endif
 
-ComparableFilename ToComparableFilename(const std::string filename) {
+ComparableFilename ToComparableFilename(std::string_view filename) {
 #ifdef _WIN32
   return ToWinWide(filename);
 #else
@@ -188,7 +188,7 @@ ComparableFilename ToComparableFilename(const std::string filename) {
 #endif
 }
 
-int CompareFilenames(const std::string& lhs, const std::string& rhs) {
+int CompareFilenames(std::string_view lhs, std::string_view rhs) {
   return CompareFilenames(ToComparableFilename(lhs), ToComparableFilename(rhs));
 }
 
@@ -216,7 +216,7 @@ int CompareFilenames(const ComparableFilename& lhs,
 #endif
 }
 
-std::string NormalizeFilename(const std::string& filename) {
+std::string NormalizeFilename(std::string_view filename) {
 #ifdef _WIN32
   auto wideString = ToWinWide(filename);
 
@@ -235,7 +235,7 @@ std::string NormalizeFilename(const std::string& filename) {
 #endif
 }
 
-std::string TrimDotGhostExtension(const std::string& filename) {
+std::string TrimDotGhostExtension(std::string&& filename) {
   // If the name passed ends in '.ghost', that should be trimmed.
   if (boost::iends_with(filename, GHOST_FILE_EXTENSION)) {
     return filename.substr(0, filename.length() - GHOST_FILE_EXTENSION_LENGTH);

src/api/helpers/text.h

@@ -27,6 +27,7 @@
 
 #include <optional>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include "loot/metadata/tag.h"
@@ -47,17 +48,17 @@ typedef std::wstring ComparableFilename;
 typedef icu::UnicodeString ComparableFilename;
 #endif
 
-std::vector<Tag> ExtractBashTags(const std::string& description);
+std::vector<Tag> ExtractBashTags(std::string_view description);
 
-std::optional<std::string> ExtractVersion(const std::string& text);
+std::optional<std::string> ExtractVersion(std::string_view text);
 
-ComparableFilename ToComparableFilename(const std::string filename);
+ComparableFilename ToComparableFilename(std::string_view filename);
 
 // Compare strings as if they're filenames, respecting filesystem case
 // insensitivity on Windows. Returns -1 if lhs < rhs, 0 if lhs == rhs, and 1 if
 // lhs > rhs. The comparison may give different results on Linux, but is still
 // locale-invariant.
-int CompareFilenames(const std::string& lhs, const std::string& rhs);
+int CompareFilenames(std::string_view lhs, std::string_view rhs);
 
 int CompareFilenames(const ComparableFilename& lhs,
                      const ComparableFilename& rhs);
@@ -68,9 +69,9 @@ int CompareFilenames(const ComparableFilename& lhs,
 // different but hopefully still consistent enough with the behaviour on Windows
 // that the normalized filenames distinguish characters in a similar way to the
 // Windows filesystem.
-std::string NormalizeFilename(const std::string& filename);
+std::string NormalizeFilename(std::string_view filename);
 
-std::string TrimDotGhostExtension(const std::string& filename);
+std::string TrimDotGhostExtension(std::string&& filename);
 }
 
 #endif

src/api/metadata/condition_evaluator.cpp

@@ -32,18 +32,18 @@
 #include "loot/exception/error_categories.h"
 
 namespace loot {
-void HandleError(const std::string operation, int returnCode) {
+void HandleError(std::string_view operation, int returnCode) {
   if (returnCode == LCI_OK) {
     return;
   }
 
   const char* message = nullptr;
-  std::string err = "Failed to " + operation + ". ";
+  std::string err;
   lci_get_error_message(&message);
   if (message == nullptr) {
-    err += "Error code: " + std::to_string(returnCode);
+    err = fmt::format("Failed to {}. Error code: {}", operation, returnCode);
   } else {
-    err += "Details: " + std::string(message);
+    err = fmt::format("Failed to {}. Details: {}", operation, message);
   }
 
   auto logger = getLogger();
@@ -260,12 +260,12 @@ void ConditionEvaluator::SetAdditionalDataPaths(
 }
 
 bool ConditionEvaluator::Evaluate(const PluginCleaningData& cleaningData,
-                                  const std::string& pluginName) {
+                                  std::string_view pluginName) {
   if (pluginName.empty())
     return false;
 
-  return Evaluate("checksum(\"" + pluginName + "\", " +
-                  CrcToString(cleaningData.GetCRC()) + ")");
+  return Evaluate(fmt::format(
+      "checksum(\"{}\", {})", pluginName, CrcToString(cleaningData.GetCRC())));
 }
 
 void ParseCondition(const std::string& condition) {

src/api/metadata/condition_evaluator.h

@@ -30,6 +30,7 @@
 #include <filesystem>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "loot/enum/game_type.h"
 #include "loot/metadata/plugin_cleaning_data.h"
@@ -56,7 +57,7 @@ public:
 
 private:
   bool Evaluate(const PluginCleaningData& cleaningData,
-                const std::string& pluginName);
+                std::string_view pluginName);
 
   std::unique_ptr<lci_state, decltype(&lci_state_destroy)> lciState_;
 };

src/api/metadata/plugin_metadata.cpp

@@ -50,10 +50,9 @@ std::vector<T> mergeVectors(std::vector<T> first,
 }
 
 namespace loot {
-PluginMetadata::PluginMetadata(const std::string& n) : name_(n) {
-  // If the name passed ends in '.ghost', that should be trimmed.
-  name_ = TrimDotGhostExtension(n);
-
+// If the name passed ends in '.ghost', that should be trimmed.
+PluginMetadata::PluginMetadata(const std::string& n) :
+    name_(TrimDotGhostExtension(std::string(n))) {
   if (IsRegexPlugin()) {
     nameRegex_ = std::regex(name_, std::regex::ECMAScript | std::regex::icase);
   }

src/api/metadata_list.cpp

@@ -56,7 +56,7 @@ std::string read_to_string(const std::filesystem::path& filePath) {
 }
 
 std::optional<std::pair<size_t, size_t>> FindPreludeBounds(
-    const std::string& masterlist) {
+    std::string_view masterlist) {
   size_t startOfPrelude = std::string::npos;
   size_t endOfPrelude = std::string::npos;
 
@@ -118,7 +118,7 @@ std::string IndentPrelude(const std::string& prelude) {
 }
 
 std::string ReplaceMetadataListPrelude(const std::string& prelude,
-                                       const std::string& masterlist) {
+                                       std::string&& masterlist) {
   auto preludeBounds = FindPreludeBounds(masterlist);
 
   if (!preludeBounds.has_value()) {
@@ -163,11 +163,8 @@ void MetadataList::LoadWithPrelude(const std::filesystem::path& filePath,
   // retained.
   // As such, replacing the prelude needs to happen before parsing,
   // which means reading the files and performing string manipulation.
-  auto prelude_content = read_to_string(preludePath);
-  auto masterlist_content = read_to_string(filePath);
-
-  masterlist_content =
-      ReplaceMetadataListPrelude(prelude_content, masterlist_content);
+  auto masterlist_content = ReplaceMetadataListPrelude(
+      read_to_string(preludePath), read_to_string(filePath));
 
   auto stream = std::istringstream(masterlist_content);
   this->Load(stream, filePath);

src/api/metadata_list.h

@@ -28,6 +28,7 @@
 #include <filesystem>
 #include <optional>
 #include <string>
+#include <string_view>
 #include <unordered_map>
 #include <vector>
 
@@ -51,7 +52,7 @@ namespace loot {
 // YAML's block style (at least up to the end of the prelude in the
 // latter). This is true for all official files.
 std::string ReplaceMetadataListPrelude(const std::string& prelude,
-                                       const std::string& masterlist);
+                                       std::string&& masterlist);
 
 class MetadataList {
 public:

src/api/plugin.cpp

@@ -37,17 +37,20 @@
 #include "loot/exception/file_access_error.h"
 
 namespace loot {
+// Intentionally takes a copy of the first parameter.
 std::filesystem::path ReplaceExtension(std::filesystem::path path,
-                                       const std::string& newExtension) {
+                                       std::string_view newExtension) {
   return path.replace_extension(std::filesystem::u8path(newExtension));
 }
 
+// Intentionally takes a copy of the first parameter.
 std::filesystem::path GetSuffixedArchivePath(std::filesystem::path pluginPath,
-                                             const std::string& suffix,
-                                             const std::string& newExtension) {
+                                             std::string_view suffix,
+                                             std::string_view newExtension) {
   // replace_extension() with no argument just removes the existing extension.
   pluginPath.replace_extension();
-  pluginPath += suffix + newExtension;
+  pluginPath += suffix;
+  pluginPath += newExtension;
   return pluginPath;
 }
 
@@ -89,7 +92,7 @@ std::vector<std::filesystem::path> FindAssociatedArchive(
 
 std::vector<std::filesystem::path> FindAssociatedArchivesWithSuffixes(
     const std::filesystem::path& pluginPath,
-    const std::string& archiveExtension,
+    std::string_view archiveExtension,
     const std::vector<std::string>& supportedSuffixes) {
   std::vector<std::filesystem::path> paths;
 
@@ -181,14 +184,12 @@ std::vector<std::filesystem::path> FindAssociatedArchives(
   }
 }
 
-void HandleEspluginError(unsigned int returnCode,
-                         const std::string& operation) {
+void HandleEspluginError(unsigned int returnCode, std::string_view operation) {
   if (returnCode == ESP_OK) {
     return;
   }
 
-  auto err = "esplugin failed to " + operation +
-             ". Error code: " + std::to_string(returnCode);
+  auto err = fmt::format("esplugin failed to {}. Error code: {}", operation, returnCode);
 
   const char* e = nullptr;
   esp_get_error_message(&e);
@@ -207,8 +208,8 @@ void HandleEspluginError(unsigned int returnCode,
 }
 
 void HandleEspluginError(unsigned int returnCode,
-                         const std::string& message,
-                         const std::string& args...) {
+                         std::string_view message,
+                         std::string_view args...) {
   if (returnCode == ESP_OK) {
     return;
   }
@@ -228,7 +229,7 @@ void HandleEspluginError(unsigned int returnCode,
 
 Plugin::Plugin(const GameType gameType,
                const GameCache& gameCache,
-               std::filesystem::path pluginPath,
+               const std::filesystem::path& pluginPath,
                const bool headerOnly) :
     name_(gameType == GameType::openmw
               ? pluginPath.filename().u8string()
@@ -655,7 +656,7 @@ unsigned int Plugin::GetEspluginGameId(GameType gameType) {
   }
 }
 
-bool hasPluginFileExtension(std::string filename, GameType gameType) {
+bool hasPluginFileExtension(std::string_view filename, GameType gameType) {
   if (gameType != GameType::openmw &&
       boost::iends_with(filename, GHOST_FILE_EXTENSION)) {
     filename =

src/api/plugin.h

@@ -30,6 +30,7 @@
 #include <map>
 #include <set>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include "api/game/load_order_handler.h"
@@ -53,7 +54,7 @@ class Plugin final : public PluginSortingInterface {
 public:
   explicit Plugin(const GameType gameType,
                   const GameCache& gameCache,
-                  std::filesystem::path pluginPath,
+                  const std::filesystem::path& pluginPath,
                   const bool headerOnly);
 
   void ResolveRecordIds(Vec_PluginMetadata* pluginsMetadata) const;
@@ -116,7 +117,7 @@ private:
 
 std::string GetArchiveFileExtension(const GameType gameType);
 
-bool hasPluginFileExtension(std::string filename, GameType gameType);
+bool hasPluginFileExtension(std::string_view filename, GameType gameType);
 
 bool equivalent(const std::filesystem::path& path1,
                 const std::filesystem::path& path2);

src/api/sorting/group_sort.cpp

@@ -171,7 +171,7 @@ GroupGraph BuildGroupGraph(const std::vector<Group>& masterlistGroups,
   return graph;
 }
 
-vertex_t GetVertexByName(const GroupGraph& graph, const std::string& name) {
+vertex_t GetVertexByName(const GroupGraph& graph, std::string_view name) {
   for (const auto& vertex :
        boost::make_iterator_range(boost::vertices(graph))) {
     if (graph[vertex] == name) {
@@ -184,12 +184,12 @@ vertex_t GetVertexByName(const GroupGraph& graph, const std::string& name) {
     logger->error("Can't find group with name \"{}\"", name);
   }
 
-  throw std::invalid_argument("Can't find group with name \"" + name + "\"");
+  throw std::invalid_argument("Can't find group with name \"" + std::string(name) + "\"");
 }
 
 std::vector<Vertex> GetGroupsPath(const GroupGraph& graph,
-                                  const std::string& fromGroupName,
-                                  const std::string& toGroupName) {
+                                  std::string_view fromGroupName,
+                                  std::string_view toGroupName) {
   auto logger = getLogger();
 
   auto fromVertex = GetVertexByName(graph, fromGroupName);

src/api/sorting/group_sort.h

@@ -27,6 +27,7 @@
 
 #include <boost/graph/adjacency_list.hpp>
 #include <string>
+#include <string_view>
 #include <unordered_map>
 #include <vector>
 
@@ -45,7 +46,7 @@ GroupGraph BuildGroupGraph(const std::vector<Group>& masterlistGroups,
                            const std::vector<Group>& userGroups);
 
 std::vector<Vertex> GetGroupsPath(const GroupGraph& groupGraph,
-                                  const std::string& fromGroupName,
-                                  const std::string& toGroupName);
+                                  std::string_view fromGroupName,
+                                  std::string_view toGroupName);
 }
 #endif

src/api/sorting/plugin_graph.cpp

@@ -33,6 +33,7 @@
 #include <boost/graph/iteration_macros.hpp>
 #include <boost/graph/topological_sort.hpp>
 #include <queue>
+#include <string_view>
 
 #include "api/helpers/logging.h"
 #include "api/helpers/text.h"
@@ -918,11 +919,11 @@ void PluginGraph::AddHardcodedPluginEdges(
   // Build the vertex map for implicitly active plugins and record the vertices
   // for other plugins.
   for (const auto& vertex : boost::make_iterator_range(GetVertices())) {
-    const auto pluginName = GetPlugin(vertex).GetName();
+    const auto& pluginName = GetPlugin(vertex).GetName();
     const auto it =
         std::find_if(hardcodedPlugins.begin(),
                      hardcodedPlugins.end(),
-                     [&](const std::string& name) {
+                     [&](std::string_view name) {
                        return CompareFilenames(name, pluginName) == 0;
                      });
 

src/api/sorting/plugin_sort.cpp

@@ -48,8 +48,8 @@ std::vector<PluginSortingData> GetPluginsSortingData(
     const auto userMetadata = db.GetPluginUserMetadata(pluginFilename, true)
                                   .value_or(PluginMetadata(pluginFilename));
 
-    const auto pluginSortingData = PluginSortingData(
-        plugin, masterlistMetadata, userMetadata, i);
+    const auto pluginSortingData =
+        PluginSortingData(plugin, masterlistMetadata, userMetadata, i);
 
     pluginsSortingData.push_back(pluginSortingData);
     i += 1;
@@ -77,7 +77,7 @@ void ValidatePluginGroups(const std::vector<PluginSortingData>& plugins,
 
 bool IsInRange(const std::vector<PluginSortingData>::const_iterator& begin,
                const std::vector<PluginSortingData>::const_iterator& end,
-               const std::string& name) {
+               std::string_view name) {
   return std::any_of(begin, end, [&](const PluginSortingData& plugin) {
     return CompareFilenames(plugin.GetName(), name) == 0;
   });
@@ -91,10 +91,10 @@ void ValidateSpecificAndHardcodedEdges(
     const std::vector<std::string>& hardcodedPlugins) {
   const auto logger = getLogger();
 
-  const auto isNonMaster = [&](const std::string& name) {
+  const auto isNonMaster = [&](std::string_view name) {
     return IsInRange(firstNonMaster, end, name);
   };
-  const auto isBlueprintMaster = [&](const std::string& name) {
+  const auto isBlueprintMaster = [&](std::string_view name) {
     return IsInRange(firstBlueprintMaster, firstNonMaster, name);
   };
 

src/api/sorting/plugin_sort.h

@@ -26,6 +26,7 @@
 #define LOOT_API_SORTING_PLUGIN_SORT
 
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include "api/game/game.h"

src/tests/api/internals/metadata_list_test.h

@@ -452,7 +452,7 @@ TEST(ReplaceMetadataListPrelude, shouldReturnAnEmptyStringIfGivenEmptyStrings) {
   std::string prelude = "";
   std::string masterlist = "";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::string(masterlist));
 
   EXPECT_EQ(masterlist, result);
 }
@@ -466,7 +466,7 @@ TEST(ReplaceMetadataListPrelude, shouldNotChangeAMasterlistWithNoPrelude) {
   - name: a.esp
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::string(masterlist));
 
   EXPECT_EQ(masterlist, result);
 }
@@ -484,7 +484,7 @@ plugins:
   - name: a.esp
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::move(masterlist));
 
   auto expectedResult = R"(prelude:
   globals:
@@ -510,7 +510,7 @@ prelude:
 
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::move(masterlist));
 
   auto expectedResult = R"(plugins:
   - name: a.esp
@@ -540,7 +540,7 @@ plugins:
   - name: a.esp
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::move(masterlist));
 
   auto expectedResult = R"(
 common:
@@ -573,7 +573,7 @@ plugins:
   - name: a.esp
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::move(masterlist));
 
   auto expectedResult = R"(prelude:
   globals:
@@ -597,7 +597,7 @@ plugins:
   - name: a.esp
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::move(masterlist));
 
   auto expectedResult = R"(prelude:
   globals: [{type: note, content: A message.}]
@@ -612,7 +612,7 @@ TEST(ReplaceMetadataListPrelude, doesNotChangeAFlowStyleMasterlist) {
   std::string prelude = "globals: [{type: note, content: A message.}]";
   std::string masterlist = "{prelude: {}, plugins: [{name: a.esp}]}";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::string(masterlist));
 
   EXPECT_EQ(masterlist, result);
 }
@@ -631,7 +631,7 @@ plugins:
   - name: a.esp
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::move(masterlist));
 
   auto expectedResult = R"(prelude:
   globals:
@@ -658,7 +658,7 @@ plugins:
   - name: a.esp
 )";
 
-  auto result = ReplaceMetadataListPrelude(prelude, masterlist);
+  auto result = ReplaceMetadataListPrelude(prelude, std::move(masterlist));
 
   auto expectedResult = R"(prelude:
   globals: