refactor zen command return value handling (#487)

- Improvement: Use consistent language for command line argument parsing errors
- Improvement: Changed zen command parsing errors to output help first and error last to make it easier to spot the error
- Improvement: Refactor zen command return codes to conform to valid Linux range (0-255)

        kSuccess     = 0,
        kOtherError  = 1,
        kBadInput    = 2,

        kOutOfMemory = 16,
        kOutOfDisk   = 17,

        kAssertError = 70,
        
        kHttpOtherClientError = 80,
        kHttpCantConnectError = 81,
        kHttpNotFound         = 66,  // NotFound(404)
        kHttpUnauthorized     = 77,  // Unauthorized(401),
        kHttpSLLError         = 82,
        kHttpForbidden        = 83,  // Forbidden(403)
        kHttpTimeout          = 84,  // RequestTimeout(408)
        kHttpConflict         = 85,  // Conflict(409)
        kHttpNoHost           = 86,
        
        kHttpOtherServerError	   = 90,
        kHttpInternalServerError = 91,  // InternalServerError(500)
        kHttpServiceUnavailable  = 69,  // ServiceUnavailable(503)
        kHttpBadGateway          = 92,  // BadGateway(502)
        kHttpGatewayTimeout      = 93,  // GatewayTimeout(504)

1 files changed, 9 insertions, 13 deletions

diff --git a/src/zen/cmds/serve_cmd.cpp b/src/zen/cmds/serve_cmd.cpp
index cfaa12bc0..49389bcdf 100644
--- a/src/zen/cmds/serve_cmd.cpp
+++ b/src/zen/cmds/serve_cmd.cpp
@@ -34,19 +34,19 @@ ServeCommand::~ServeCommand()
 {
 }
 
-int
+void
 ServeCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 {
 	ZEN_UNUSED(GlobalOptions);
 
 	if (!ParseOptions(argc, argv))
 	{
-		return 0;
+		return;
 	}
 
 	if (m_ProjectName.empty())
 	{
-		throw zen::OptionParseException("command requires a project");
+		throw OptionParseException("'--project' is required", m_Options.help());
 	}
 
 	if (m_OplogName.empty())
@@ -58,18 +58,18 @@ ServeCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		}
 		else
 		{
-			throw zen::OptionParseException("command requires an oplog");
+			throw OptionParseException("'--oplog' is required", m_Options.help());
 		}
 	}
 
 	if (m_RootPath.empty())
 	{
-		throw zen::OptionParseException("command requires a root path");
+		throw OptionParseException("'--path' is required", m_Options.help());
 	}
 
 	if (!IsDir(m_RootPath))
 	{
-		throw zen::OptionParseException(fmt::format("path must exist and must be a directory: '{}'", m_RootPath));
+		throw std::runtime_error(fmt::format("'--path' ('{}') must exist and must be a directory", m_RootPath));
 	}
 
 	uint16_t ServerPort = 0;
@@ -95,7 +95,7 @@ ServeCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 		{
 			ZEN_CONSOLE_ERROR("Failed to spawn server on port {}: '{}'", ServerPort, Ex.what());
 
-			throw zen::OptionParseException("unable to resolve server specification (even after spawning server)");
+			throw std::runtime_error("Unable to resolve server specification (even after spawning server)");
 		}
 	}
 	else
@@ -197,8 +197,7 @@ ServeCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 
 		if (auto NewProjectResponse = Client.Post(ProjectUri, Project.Save()); !NewProjectResponse)
 		{
-			// TODO: include details
-			throw std::runtime_error("failed to create project");
+			NewProjectResponse.ThrowError("Failed to create project");
 		}
 	}
 
@@ -212,8 +211,7 @@ ServeCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 
 		if (auto NewOplogResponse = Client.Post(ProjectOplogUri, Oplog.Save()); !NewOplogResponse)
 		{
-			// TODO: include details
-			throw std::runtime_error("failed to create oplog");
+			NewOplogResponse.ThrowError("Failed to create oplog");
 		}
 	}
 
@@ -233,8 +231,6 @@ ServeCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
 #if ZEN_PLATFORM_WINDOWS
 	_getch();  // TEMPORARY HACK
 #endif
-
-	return 0;
 }
 
 }  // namespace zen