lib/cli: Fix the usage text generator not dealing well with absent sections

src/lib/cli.cpp

@@ -260,7 +260,11 @@ namespace CLI {
     }
 
     std::string ArgumentsParser::getUsage(){
-        std::string usageString = "Help: " + this->programName + "\n\n\t" + this->description + "\n\n" + "Usage: " + this->programName;
+        std::string usageString = "";
+        if (this->description != "") {
+            usageString += "Help: " + this->programName + "\n\n\t" + this->description + "\n\n";
+        }
+        usageString += "Usage: " + this->programName + " ";
 
         if(!this->flagsByShortName.empty()){
             usageString += "[-";
@@ -284,14 +288,19 @@ namespace CLI {
             usageString += argument.placeholder + " ";
         }
 
-        usageString += "\n\nFlags:\n";
+        usageString.push_back('\n');
+
+        if(!this->flagsByShortName.empty()){
+            usageString += "\nFlags:\n";
 
             for(const auto& [key, value]: this->flagsByShortName){
                 usageString += "\t-";
                 usageString.push_back(key);
                 usageString += ", --" + value->longName + "\n\t\t" + value->description + "\n";
             }
+        }
 
+        if(!this->optionsByShortName.empty()){
             usageString += "\nOptions:\n";
 
             for(const auto& [key, value]: this->optionsByShortName){
@@ -299,12 +308,15 @@ namespace CLI {
                 usageString.push_back(key);
                 usageString += " " + value->placeholder + ", --" + value->longName + "=" + value->placeholder + "\n\t\t" + value->description + "\n";
             }
+        }
 
+        if(!this->arguments.empty()){
             usageString += "\nArguments:\n";
 
             for(const auto& argument: this->arguments){
                 usageString += "\t" + argument.placeholder + "\n\t\t" + argument.description + "\n";
             }
+        }
 
         return usageString;
     }

src/test/cli_argument_parser.cpp

@@ -23,7 +23,7 @@
 
 int main() {
     std::cout << "################################################################################" << std::endl;
-    std::cout << "CLI argument parser tests" << std::endl;
+    std::cout << "CLI argument parsing tests" << std::endl;
     std::cout << "################################################################################" << std::endl;
 
     // Valid parameter test ############################################
@@ -636,6 +636,11 @@ int main() {
     delete[] tooManyArgumentsTestParameterList;
     std::cout << "Passed too many arguments test." << std::endl;
 
+    std::cout << "################################################################################" << std::endl;
+    std::cout << "CLI argument parser help tests" << std::endl;
+    std::cout << "################################################################################" << std::endl;
+
+    // normal usage with all types of CLI input ########################
     std::vector<CLI::Flag> helpTestFlags;
     helpTestFlags.push_back(CLI::Flag('a', "apple", "throws an apple on Newton's head."));
     helpTestFlags.push_back(CLI::Flag('y', "yapple", "throws an yapple on Newton's head."));
@@ -653,8 +658,93 @@ int main() {
     CLI::ArgumentsParser helpTestParser = CLI::ArgumentsParser(1, helpTestCommand, helpTestFlags, helpTestOptions, helpTestArguments, "Create a universe with a banana and an apple.");
 
     ASSERT(helpTestParser.getUsage() == "Help: universecreator\n\n\tCreate a universe with a banana and an apple.\n\nUsage: universecreator [-ay] [-b BANANA] [-c CORNHUBBBBB] WASH SHAKE \n\nFlags:\n\t-a, --apple\n\t\tthrows an apple on Newton's head.\n\t-y, --yapple\n\t\tthrows an yapple on Newton's head.\n\nOptions:\n\t-b BANANA, --banana=BANANA\n\t\tsmack someone with a ripe banana.\n\t-c CORNHUBBBBB, --corn=CORNHUBBBBB\n\t\tvisit cornhub.\n\nArguments:\n\tWASH\n\t\tNumber of times to wash my shark.\n\tSHAKE\n\t\tNumber of times to shake fist at cloud.\n");
-    std::cout << "Passed Argument Parser usage test." << std::endl;
+    std::cout << "Passed normal usage test." << std::endl;
 
+    // no description ##################################################
+    std::vector<CLI::Flag> usageOnlyTestFlags;
+    usageOnlyTestFlags.push_back(CLI::Flag('a', "apple", "throws an apple on Newton's head."));
+    usageOnlyTestFlags.push_back(CLI::Flag('y', "yapple", "throws an yapple on Newton's head."));
+
+    std::vector<CLI::Option> usageOnlyTestOptions;
+    usageOnlyTestOptions.push_back(CLI::Option('b', "banana", "BANANA", "smack someone with a ripe banana."));
+    usageOnlyTestOptions.push_back(CLI::Option('c', "corn", "CORNHUBBBBB", "visit cornhub."));
+
+    std::vector<CLI::Argument> usageOnlyTestArguments;
+    usageOnlyTestArguments.push_back(CLI::Argument("WASH", "Number of times to wash my shark."));
+    usageOnlyTestArguments.push_back(CLI::Argument("SHAKE", "Number of times to shake fist at cloud."));
+
+    const char** usageOnlyTestCommand = new const char*[1];
+    usageOnlyTestCommand[0] = "universecreator";
+    CLI::ArgumentsParser usageOnlyTestParser = CLI::ArgumentsParser(1, usageOnlyTestCommand, usageOnlyTestFlags, usageOnlyTestOptions, usageOnlyTestArguments);
+
+    ASSERT(usageOnlyTestParser.getUsage() == "Usage: universecreator [-ay] [-b BANANA] [-c CORNHUBBBBB] WASH SHAKE \n\nFlags:\n\t-a, --apple\n\t\tthrows an apple on Newton's head.\n\t-y, --yapple\n\t\tthrows an yapple on Newton's head.\n\nOptions:\n\t-b BANANA, --banana=BANANA\n\t\tsmack someone with a ripe banana.\n\t-c CORNHUBBBBB, --corn=CORNHUBBBBB\n\t\tvisit cornhub.\n\nArguments:\n\tWASH\n\t\tNumber of times to wash my shark.\n\tSHAKE\n\t\tNumber of times to shake fist at cloud.\n");
+    std::cout << "Passed normal usage without description test." << std::endl;
+
+    // no flags ########################################################
+    std::vector<CLI::Flag> noFlagsFlags;
+
+    std::vector<CLI::Option> noFlagsOptions;
+    noFlagsOptions.push_back(CLI::Option('b', "banana", "BANANA", "smack someone with a ripe banana."));
+    noFlagsOptions.push_back(CLI::Option('c', "corn", "CORNHUBBBBB", "visit cornhub."));
+
+    std::vector<CLI::Argument> noFlagsArguments;
+    noFlagsArguments.push_back(CLI::Argument("WASH", "Number of times to wash my shark."));
+    noFlagsArguments.push_back(CLI::Argument("SHAKE", "Number of times to shake fist at cloud."));
+
+    const char** noFlagsCommand = new const char*[1];
+    noFlagsCommand[0] = "universecreator";
+    CLI::ArgumentsParser noFlagsParser = CLI::ArgumentsParser(1, noFlagsCommand, noFlagsFlags, noFlagsOptions, noFlagsArguments, "Create a universe with a banana and an apple.");
+
+    ASSERT(noFlagsParser.getUsage() == "Help: universecreator\n\n\tCreate a universe with a banana and an apple.\n\nUsage: universecreator [-b BANANA] [-c CORNHUBBBBB] WASH SHAKE \n\nOptions:\n\t-b BANANA, --banana=BANANA\n\t\tsmack someone with a ripe banana.\n\t-c CORNHUBBBBB, --corn=CORNHUBBBBB\n\t\tvisit cornhub.\n\nArguments:\n\tWASH\n\t\tNumber of times to wash my shark.\n\tSHAKE\n\t\tNumber of times to shake fist at cloud.\n");
+
+    // no options ######################################################
+    std::vector<CLI::Flag> noOptionsFlags;
+    noOptionsFlags.push_back(CLI::Flag('a', "apple", "throws an apple on Newton's head."));
+    noOptionsFlags.push_back(CLI::Flag('y', "yapple", "throws an yapple on Newton's head."));
+
+    std::vector<CLI::Option> noOptionsOptions;
+
+    std::vector<CLI::Argument> noOptionsArguments;
+    noOptionsArguments.push_back(CLI::Argument("WASH", "Number of times to wash my shark."));
+    noOptionsArguments.push_back(CLI::Argument("SHAKE", "Number of times to shake fist at cloud."));
+
+    const char** noOptionsCommand = new const char*[1];
+    noOptionsCommand[0] = "universecreator";
+    CLI::ArgumentsParser noOptionsParser = CLI::ArgumentsParser(1, noOptionsCommand, noOptionsFlags, noOptionsOptions, noOptionsArguments, "Create a universe with a banana and an apple.");
+
+    ASSERT(noOptionsParser.getUsage() == "Help: universecreator\n\n\tCreate a universe with a banana and an apple.\n\nUsage: universecreator [-ay] WASH SHAKE \n\nFlags:\n\t-a, --apple\n\t\tthrows an apple on Newton's head.\n\t-y, --yapple\n\t\tthrows an yapple on Newton's head.\n\nArguments:\n\tWASH\n\t\tNumber of times to wash my shark.\n\tSHAKE\n\t\tNumber of times to shake fist at cloud.\n");
+
+    // no arguments ####################################################
+    std::vector<CLI::Flag> noArgumentsFlags;
+    noArgumentsFlags.push_back(CLI::Flag('a', "apple", "throws an apple on Newton's head."));
+    noArgumentsFlags.push_back(CLI::Flag('y', "yapple", "throws an yapple on Newton's head."));
+
+    std::vector<CLI::Option> noArgumentsOptions;
+    noArgumentsOptions.push_back(CLI::Option('b', "banana", "BANANA", "smack someone with a ripe banana."));
+    noArgumentsOptions.push_back(CLI::Option('c', "corn", "CORNHUBBBBB", "visit cornhub."));
+
+    std::vector<CLI::Argument> noArgumentsArguments;
+
+    const char** noArgumentsCommand = new const char*[1];
+    noArgumentsCommand[0] = "universecreator";
+    CLI::ArgumentsParser noArgumentsParser = CLI::ArgumentsParser(1, noArgumentsCommand, noArgumentsFlags, noArgumentsOptions, noArgumentsArguments, "Create a universe with a banana and an apple.");
+
+    ASSERT(noArgumentsParser.getUsage() == "Help: universecreator\n\n\tCreate a universe with a banana and an apple.\n\nUsage: universecreator [-ay] [-b BANANA] [-c CORNHUBBBBB] \n\nFlags:\n\t-a, --apple\n\t\tthrows an apple on Newton's head.\n\t-y, --yapple\n\t\tthrows an yapple on Newton's head.\n\nOptions:\n\t-b BANANA, --banana=BANANA\n\t\tsmack someone with a ripe banana.\n\t-c CORNHUBBBBB, --corn=CORNHUBBBBB\n\t\tvisit cornhub.\n");
+    std::cout << "Passed absent section usage test." << std::endl;
+
+    // no CLI input ####################################################
+    std::vector<CLI::Flag> noCLIFlags;
+
+    std::vector<CLI::Option> noCLIOptions;
+
+    std::vector<CLI::Argument> noCLIArguments;
+
+    const char** noCLICommand = new const char*[1];
+    noCLICommand[0] = "universecreator";
+    CLI::ArgumentsParser noCLIParser = CLI::ArgumentsParser(1, noCLICommand, noCLIFlags, noCLIOptions, noCLIArguments, "Create a universe with a banana and an apple.");
+
+    ASSERT(noCLIParser.getUsage() == "Help: universecreator\n\n\tCreate a universe with a banana and an apple.\n\nUsage: universecreator \n");
+    std::cout << "Passed no CLI input usage test." << std::endl;
 
     return 0;
 }