edit error codes

Author: SandrineP

src/subcommand/diff_subcommand.cpp

@@ -5,6 +5,7 @@
 #include <termcolor/termcolor.hpp>
 
 #include "../utils/common.hpp"
+#include "../utils/git_exception.hpp"
 #include "../subcommand/diff_subcommand.hpp"
 #include "../wrapper/patch_wrapper.hpp"
 #include "../wrapper/repository_wrapper.hpp"
@@ -212,7 +213,7 @@ diff_wrapper compute_diff_no_index(std::vector<std::string> files, git_diff_opti
 {
 	if (files.size() != 2)
     {
-        throw git_exception("two files should be provided as arguments", -1);   //TODO: check error + code
+        throw git_exception("usage: git diff --no-index [<options>] <path> <path> [<pathspec>...]", git2cpp_error_code::BAD_ARGUMENT);
     }
 
     git_diff_options_init(&diffopts, GIT_DIFF_OPTIONS_VERSION);
@@ -222,11 +223,11 @@ diff_wrapper compute_diff_no_index(std::vector<std::string> files, git_diff_opti
 
     if (file1_str.empty())
     {
-        throw git_exception("file " + files[0] + " cannot be read", -1);   //TODO: check error + code
+        throw git_exception("Cannot read file: " + files[0], git2cpp_error_code::GENERIC_ERROR);   //TODO: check error code with git
     }
     if (file2_str.empty())
     {
-        throw git_exception("file " + files[1] + "  cannot be read", -1);   //TODO: check error + code
+        throw git_exception("Cannot read file: " + files[1], git2cpp_error_code::GENERIC_ERROR);   //TODO: check error code with git
     }
 
     auto patch = patch_wrapper::patch_from_files(files[0], file1_str, files[1], file2_str, &diffopts);

src/utils/common.cpp

@@ -109,7 +109,7 @@ std::string read_file(const std::string& path)
     std::ifstream file(path, std::ios::binary);
     if (!file)
     {
-        throw git_exception("Cannot read file: " + path, -1);
+        throw git_exception("error: Could not access " + path, git2cpp_error_code::GENERIC_ERROR);
     }
     std::stringstream buffer;
     buffer << file.rdbuf();

src/utils/git_exception.cpp

@@ -10,11 +10,14 @@ void throw_if_error(int exit_code)
     }
 }
 
-
 git_exception::git_exception(const std::string_view message, int error_code)
     : m_message(message), m_error_code(error_code)
 {}
 
+git_exception::git_exception(const std::string_view message, git2cpp_error_code error_code)
+    : git_exception(message, static_cast<int>(error_code))
+{}
+
 int git_exception::error_code() const
 {
     return m_error_code;

src/utils/git_exception.hpp

@@ -3,13 +3,20 @@
 #include <exception>
 #include <string>
 
+enum class git2cpp_error_code
+{
+    GENERIC_ERROR = -1,
+    BAD_ARGUMENT = 129,
+};
+
 void throw_if_error(int exit_code);
 
 class git_exception : public std::exception
 {
 public:
 
     git_exception(const std::string_view message, int error_code);
+    git_exception(const std::string_view message, git2cpp_error_code error_code);
 
     int error_code() const;