Update clang-format and add clang-tidy

source/Configuration.hpp

@@ -38,7 +38,7 @@ class Configuration {
   Configuration() = default;
 
   // Constructor. Constructs configuration details by reading them from a YAML configuration file.
-  Configuration(const std::filesystem::path& path) {
+  explicit Configuration(const std::filesystem::path& path) {
     if (!std::filesystem::exists(path)) {
       std::cout << "Cannot find the YAML configuration file at " << path
                 << "; please check the file path." << std::endl;
@@ -112,20 +112,20 @@ class Configuration {
 
   // Subject of the email message that will be sent to each participant. A default value is used if
   // no message subject is defined in the YAML configuration file.
-  const std::string& MessageSubject() const noexcept {
+  [[nodiscard]] const std::string& MessageSubject() const noexcept {
     return message_subject_;
   }
 
   // Body of the email message that will be sent to each participant. A default value is used if no
   // message body is defined in the YAML configuration file. A brief greeting of "Hello <name>" is
   // automatically prepended to this body, and information regarding the participant's giftee is
   // automatically appended to this body.
-  const std::string& MessageBody() const noexcept {
+  [[nodiscard]] const std::string& MessageBody() const noexcept {
     return message_body_;
   }
 
   // Set of participants.
-  const std::set<Participant>& Participants() const noexcept {
+  [[nodiscard]] const std::set<Participant>& Participants() const noexcept {
     return participants_;
   }
 

source/Matchings.hpp

@@ -83,7 +83,7 @@ class Matchings {
   }
 
   // Constructor. Constructs matchings by reading them from a given YAML file.
-  Matchings(const std::filesystem::path& path) {
+  explicit Matchings(const std::filesystem::path& path) {
     if (!std::filesystem::exists(path)) {
       std::cout << "Cannot find the YAML matchings file at " << path
                 << "; please check the file path." << std::endl;
@@ -132,7 +132,7 @@ class Matchings {
   // Map of gifter participant names to giftee participant names. For example, the map element
   // {Alice, Bob} means that Alice is the gifter and Bob is the giftee, such that Alice is Bob's
   // Secret Santa.
-  const std::map<std::string, std::string>& GiftersToGiftees() const noexcept {
+  [[nodiscard]] const std::map<std::string, std::string>& GiftersToGiftees() const noexcept {
     return gifters_to_giftees_;
   }
 

source/Messenger/Argument.hpp

@@ -48,17 +48,17 @@ static const std::string Path{"<path>"};
 }  // namespace Value
 
 // Prints usage instructions and exits. Optional.
-std::string_view Help() {
+[[nodiscard]] std::string_view Help() {
   return Key::Help;
 }
 
 // Path to the YAML configuration file to be read. Required.
-std::string Configuration() {
+[[nodiscard]] std::string Configuration() {
   return Key::Configuration + " " + Value::Path;
 }
 
 // Path to the YAML matchings file to be read. Required.
-std::string Matchings() {
+[[nodiscard]] std::string Matchings() {
   return Key::Matchings + " " + Value::Path;
 }
 

source/Messenger/Emailer.hpp

@@ -29,7 +29,7 @@ namespace SecretSanta::Messenger {
 
 // Composes the full email message body for a given gifter. Prefixes a brief greeting to the given
 // main message body and appends the giftee information.
-std::string ComposeFullMessageBody(
+[[nodiscard]] std::string ComposeFullMessageBody(
     const Participant& gifter, const Participant& giftee, const std::string& main_message_body) {
   std::string text;
 
@@ -53,8 +53,9 @@ std::string ComposeFullMessageBody(
 }
 
 // Composes the command used to invoke the S-nail utility for a given gifter.
-std::string ComposeCommand(const Participant& gifter, const std::string& message_subject,
-                           const std::string& message_body) {
+[[nodiscard]] std::string ComposeCommand(
+    const Participant& gifter, const std::string& message_subject,
+    const std::string& message_body) {
   return "echo \"" + message_body + "\" | s-nail --subject \"" + message_subject + "\" "
          + gifter.Email();
 }
@@ -91,7 +92,7 @@ void ComposeAndSendEmailMessages(const Configuration& configuration, const Match
 
     // Obtain the giftee information.
     const std::set<Participant>::const_iterator giftee =
-        configuration.Participants().find({gifter_name_and_giftee_name->second});
+        configuration.Participants().find(Participant{gifter_name_and_giftee_name->second});
 
     if (giftee == configuration.Participants().cend()) {
       continue;

source/Messenger/Settings.hpp

@@ -64,12 +64,12 @@ class Settings {
   Settings& operator=(Settings&& other) noexcept = delete;
 
   // Path to the YAML configuration file to be read.
-  const std::filesystem::path& ConfigurationFile() const noexcept {
+  [[nodiscard]] const std::filesystem::path& ConfigurationFile() const noexcept {
     return configuration_file_;
   }
 
   // Path to the YAML matchings file to be read.
-  const std::filesystem::path& MatchingsFile() const noexcept {
+  [[nodiscard]] const std::filesystem::path& MatchingsFile() const noexcept {
     return matchings_file_;
   }
 
@@ -142,7 +142,7 @@ class Settings {
   }
 
   // Returns whether there is at least one more element after the given element index.
-  bool AtLeastOneMore(const int index, const int count) const noexcept {
+  [[nodiscard]] bool AtLeastOneMore(const int index, const int count) const noexcept {
     return index + 1 < count;
   }
 

source/Participant.hpp

@@ -37,14 +37,14 @@ class Participant {
 
   // Constructor. Creates a participant from a given name. The email address, street address, and
   // instructions are empty. Only used for searching through a set of participants.
-  Participant(const std::string& name) : name_(name) {}
+  explicit Participant(const std::string& name) : name_(name) {}
 
   // Constructor. Creates a participant from a YAML node of the form:
   //   Alice Smith:
   //     email: [email protected]
   //     address: 123 First Ave, Apt 1, Townsville, CA, 91234 USA
   //     instructions: Leave the package with the doorman in the lobby.
-  Participant(const YAML::Node& node) {
+  explicit Participant(const YAML::Node& node) {
     if (!node.IsMap()) {
       return;
     }
@@ -90,27 +90,27 @@ class Participant {
   Participant& operator=(Participant&& other) noexcept = default;
 
   // Name of this participant. Each participant must have a unique name.
-  const std::string& Name() const noexcept {
+  [[nodiscard]] const std::string& Name() const noexcept {
     return name_;
   }
 
   // Email address of this participant.
-  const std::string& Email() const noexcept {
+  [[nodiscard]] const std::string& Email() const noexcept {
     return email_;
   }
 
   // Street address of this participant.
-  const std::string& Address() const noexcept {
+  [[nodiscard]] const std::string& Address() const noexcept {
     return address_;
   }
 
   // Additional instructions for mailing packages to this participant.
-  const std::string& Instructions() const noexcept {
+  [[nodiscard]] const std::string& Instructions() const noexcept {
     return instructions_;
   }
 
   // Prints this participant as a string.
-  std::string Print() const noexcept {
+  [[nodiscard]] std::string Print() const noexcept {
     std::string details;
 
     if (!email_.empty()) {
@@ -144,7 +144,7 @@ class Participant {
   //     email: [email protected]
   //     address: 123 First Ave, Apt 1, Townsville, CA, 91234 USA
   //     instructions: Leave the package with the doorman in the lobby.
-  YAML::Node YAML() const {
+  [[nodiscard]] YAML::Node YAML() const {
     YAML::Node node;
     node[name_]["email"] = email_;
     node[name_]["address"] = address_;

source/Randomizer/Argument.hpp

@@ -54,22 +54,22 @@ static const std::string Path{"<path>"};
 }  // namespace Value
 
 // Prints usage instructions and exits. Optional.
-std::string_view Help() {
+[[nodiscard]] std::string_view Help() {
   return Key::Help;
 }
 
 // Path to the YAML configuration file to be read. Required.
-std::string Configuration() {
+[[nodiscard]] std::string Configuration() {
   return Key::Configuration + " " + Value::Path;
 }
 
 // Path to the YAML matchings file to be written. Optional.
-std::string Matchings() {
+[[nodiscard]] std::string Matchings() {
   return Key::Matchings + " " + Value::Path;
 }
 
 // Seed value for pseudo-random number generation. Optional.
-std::string Seed() {
+[[nodiscard]] std::string Seed() {
   return Key::Seed + " " + Value::Integer;
 }
 

source/Randomizer/Settings.hpp

@@ -64,18 +64,18 @@ class Settings {
   Settings& operator=(Settings&& other) noexcept = delete;
 
   // Path to the YAML configuration file to be read.
-  const std::filesystem::path& ConfigurationFile() const noexcept {
+  [[nodiscard]] const std::filesystem::path& ConfigurationFile() const noexcept {
     return configuration_file_;
   }
 
   // Path to the YAML matchings file to be written. If empty, no matchings file is written.
-  const std::filesystem::path& MatchingsFile() const noexcept {
+  [[nodiscard]] const std::filesystem::path& MatchingsFile() const noexcept {
     return matchings_file_;
   }
 
   // Optional seed value for pseudo-random number generation. If no value is specified, the seed
   // value is randomized.
-  constexpr const std::optional<int64_t>& RandomSeed() const noexcept {
+  [[nodiscard]] constexpr const std::optional<int64_t>& RandomSeed() const noexcept {
     return random_seed_;
   }
 
@@ -156,7 +156,7 @@ class Settings {
   }
 
   // Returns whether there is at least one more element after the given element index.
-  bool AtLeastOneMore(const int index, const int count) const noexcept {
+  [[nodiscard]] bool AtLeastOneMore(const int index, const int count) const noexcept {
     return index + 1 < count;
   }
 

source/String.hpp

@@ -31,7 +31,8 @@ namespace SecretSanta {
 
 // Returns a copy of a given string where the copy has been padded to a given length with trailing
 // spaces. If the given string is already longer than the given length, nothing is changed.
-std::string PadToLength(const std::string_view text, const std::size_t length) noexcept {
+[[nodiscard]] std::string PadToLength(
+    const std::string_view text, const std::size_t length) noexcept {
   std::string padded_text{text};
   const std::size_t text_length = text.size();
   if (length > text_length) {

test/Matchings.cpp

@@ -38,7 +38,7 @@ std::set<Participant> CreateSampleParticipants() {
 }
 
 TEST(Matchings, ComparisonOperators) {
-  const Matchings first{{CreateSampleParticipantA()}};
+  const Matchings first{std::set<Participant>{Participant{CreateSampleParticipantA()}}};
   const Matchings second{CreateSampleParticipants()};
   EXPECT_EQ(first, first);
   EXPECT_NE(first, second);
@@ -56,7 +56,7 @@ TEST(Matchings, ConstructorFromNoParticipants) {
 }
 
 TEST(Matchings, ConstructorFromOneParticipant) {
-  const Matchings matchings{{CreateSampleParticipantA()}};
+  const Matchings matchings{std::set<Participant>{Participant{CreateSampleParticipantA()}}};
   EXPECT_EQ(matchings.GiftersToGiftees().size(), 1);
   EXPECT_NE(matchings.GiftersToGiftees().find("Alice Smith"), matchings.GiftersToGiftees().cend());
   EXPECT_EQ(matchings.GiftersToGiftees().at("Alice Smith"), "Alice Smith");

test/Messenger/Emailer.cpp

@@ -30,8 +30,8 @@ namespace SecretSanta::Messenger {
 namespace {
 
 TEST(MessengerEmailer, ComposeFullMessageBody) {
-  const Participant gifter = CreateSampleParticipantA();
-  const Participant giftee = CreateSampleParticipantB();
+  const Participant gifter{CreateSampleParticipantA()};
+  const Participant giftee{CreateSampleParticipantB()};
 
   const std::string main_message_body{
       "You are receiving this message because you opted to participate in a Secret Santa gift "
@@ -46,7 +46,7 @@ TEST(MessengerEmailer, ComposeFullMessageBody) {
 }
 
 TEST(MessengerEmailer, ComposeCommand) {
-  const Participant gifter = CreateSampleParticipantA();
+  const Participant gifter{CreateSampleParticipantA()};
   const std::string message_subject{"My Message Subject"};
   const std::string message_body{"My Message Body"};
 

test/Participant.cpp

@@ -60,7 +60,7 @@ TEST(Participant, ConstructorFromYamlNode) {
 
 TEST(Participant, CopyAssignmentOperator) {
   const Participant first{CreateSampleParticipantA()};
-  Participant second = CreateSampleParticipantB();
+  Participant second = Participant{CreateSampleParticipantB()};
   second = first;
   EXPECT_EQ(second, first);
 }
@@ -88,7 +88,7 @@ TEST(Participant, Hash) {
 
 TEST(Participant, MoveAssignmentOperator) {
   Participant first{CreateSampleParticipantA()};
-  Participant second = CreateSampleParticipantB();
+  Participant second{CreateSampleParticipantB()};
   second = std::move(first);
   EXPECT_EQ(second, Participant(CreateSampleParticipantA()));
 }
@@ -117,7 +117,7 @@ TEST(Participant, Stream) {
 
 TEST(Participant, YAML) {
   const Participant participant{CreateSampleParticipantA()};
-  const YAML::Node node = participant.YAML();
+  const YAML::Node node{participant.YAML()};
   ASSERT_TRUE(node.IsMap());
   ASSERT_EQ(node.size(), 1);
   for (const YAML::detail::iterator_value& element : node) {