From 294728e5b52bd41b38fa85e830d85fffb1e59a34 Mon Sep 17 00:00:00 2001
From: Emil Dotchevski <emildotchevski@gmail.com>
Date: Wed, 10 Feb 2021 18:35:46 -0800
Subject: [PATCH] Fixing bug in e_LastError, adding unit tests

---
 include/boost/leaf/common.hpp |  8 ++++-
 meson.build                   |  2 ++
 test/Jamfile.v2               |  2 ++
 test/e_LastError_test.cpp     | 59 +++++++++++++++++++++++++++++++++++
 test/e_errno_test.cpp         | 44 ++++++++++++++++++++++++++
 5 files changed, 114 insertions(+), 1 deletion(-)
 create mode 100644 test/e_LastError_test.cpp
 create mode 100644 test/e_errno_test.cpp

diff --git a/include/boost/leaf/common.hpp b/include/boost/leaf/common.hpp
index 6973e7c..4fad6b7 100644
--- a/include/boost/leaf/common.hpp
+++ b/include/boost/leaf/common.hpp
@@ -40,6 +40,8 @@ struct e_errno
 {
     int value;
 
+    explicit e_errno(int value=errno): value(value) { }
+
     template <class CharT, class Traits>
     friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, e_errno const & err )
     {
@@ -57,9 +59,13 @@ namespace windows
     {
         unsigned value;
 
+        explicit e_LastError(unsigned value): value(value) { }
+
 #ifdef _WIN32
+        e_LastError(): value(GetLastError()) { }
+
         template <class CharT, class Traits>
-        friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> os, e_LastError const & err )
+        friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, e_LastError const & err )
         {
             struct msg_buf
             {
diff --git a/meson.build b/meson.build
index bbe0926..29f5f4a 100644
--- a/meson.build
+++ b/meson.build
@@ -132,6 +132,8 @@ if option_enable_unit_tests
 		'defer_nested_success_exception_test',
 		'defer_nested_success_result_test',
 		'diagnostic_info_test',
+		'e_errno_test',
+		'e_LastError_test',
 		'error_code_test',
 		'error_id_test',
 		'exception_test',
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 5ecbd1a..55eac91 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -64,6 +64,8 @@ run defer_nested_new_error_result_test.cpp ;
 run defer_nested_success_exception_test.cpp ;
 run defer_nested_success_result_test.cpp ;
 run diagnostic_info_test.cpp ;
+run e_errno_test.cpp ;
+run e_LastError_test.cpp ;
 run error_code_test.cpp ;
 run error_id_test.cpp ;
 run exception_test.cpp ;
diff --git a/test/e_LastError_test.cpp b/test/e_LastError_test.cpp
new file mode 100644
index 0000000..9edfcaa
--- /dev/null
+++ b/test/e_LastError_test.cpp
@@ -0,0 +1,59 @@
+// Copyright (c) 2018-2021 Emil Dotchevski and Reverge Studios, Inc.
+
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef _WIN32
+
+#include <iostream>
+
+int main()
+{
+    std::cout << "This test requires Windows";
+    return 0;
+}
+
+#else
+
+#ifdef BOOST_LEAF_TEST_SINGLE_HEADER
+#   include "leaf.hpp"
+#else
+#   include <boost/leaf/common.hpp>
+#   include <boost/leaf/handle_errors.hpp>
+#   include <boost/leaf/result.hpp>
+#endif
+
+#include "lightweight_test.hpp"
+#include <sstream>
+
+namespace leaf = boost::leaf;
+
+int main()
+{
+    SetLastError(ERROR_FILE_NOT_FOUND);
+    std::stringstream ss;
+    ss << leaf::windows::e_LastError{};
+    BOOST_TEST(ss.str().find("The system cannot find the file specified") != std::string::npos);
+
+    int r = leaf::try_handle_all(
+        []() -> leaf::result<int>
+        {
+            SetLastError(ERROR_FILE_NOT_FOUND);
+            struct reset_LastError { ~reset_LastError() {SetLastError(0); } } reset;
+            return leaf::new_error( leaf::windows::e_LastError{} );
+        },
+        []( leaf::windows::e_LastError e )
+        {
+            BOOST_TEST_EQ(GetLastError(), 0);
+            BOOST_TEST_EQ(e.value, ERROR_FILE_NOT_FOUND);
+            return 1;
+        },
+        []
+        {
+            return 2;
+        } );
+    BOOST_TEST_EQ(r, 1);
+    return boost::report_errors();
+}
+
+#endif
diff --git a/test/e_errno_test.cpp b/test/e_errno_test.cpp
new file mode 100644
index 0000000..b868840
--- /dev/null
+++ b/test/e_errno_test.cpp
@@ -0,0 +1,44 @@
+// Copyright (c) 2018-2021 Emil Dotchevski and Reverge Studios, Inc.
+
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifdef BOOST_LEAF_TEST_SINGLE_HEADER
+#   include "leaf.hpp"
+#else
+#   include <boost/leaf/common.hpp>
+#   include <boost/leaf/handle_errors.hpp>
+#   include <boost/leaf/result.hpp>
+#endif
+
+#include "lightweight_test.hpp"
+#include <sstream>
+
+namespace leaf = boost::leaf;
+
+int main()
+{
+    errno = ENOENT;
+    std::stringstream ss;
+    ss << leaf::e_errno{};
+    BOOST_TEST(ss.str().find(std::strerror(ENOENT)) != std::string::npos);
+
+    int r = leaf::try_handle_all(
+        []() -> leaf::result<int>
+        {
+            struct reset_errno { ~reset_errno() { errno=0; } } reset;
+            return leaf::new_error( leaf::e_errno{} );
+        },
+        []( leaf::e_errno e )
+        {
+            BOOST_TEST_EQ(errno, 0);
+            BOOST_TEST_EQ(e.value, ENOENT);
+            return 1;
+        },
+        []
+        {
+            return 2;
+        } );
+    BOOST_TEST_EQ(r, 1);
+    return boost::report_errors();
+}