Common/FileSystem: Add IsAbsolutePath() and tests

src/common-tests/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_executable(common-tests
   bitutils_tests.cpp
   event_tests.cpp
+  file_system_tests.cpp
   rectangle_tests.cpp
 )
 

src/common-tests/common-tests.vcxproj

@@ -46,6 +46,7 @@
     <ClCompile Include="..\..\dep\googletest\src\gtest_main.cc" />
     <ClCompile Include="bitutils_tests.cpp" />
     <ClCompile Include="event_tests.cpp" />
+    <ClCompile Include="file_system_tests.cpp" />
     <ClCompile Include="rectangle_tests.cpp" />
   </ItemGroup>
   <PropertyGroup Label="Globals">

src/common-tests/common-tests.vcxproj.filters

@@ -5,5 +5,6 @@
     <ClCompile Include="rectangle_tests.cpp" />
     <ClCompile Include="event_tests.cpp" />
     <ClCompile Include="bitutils_tests.cpp" />
+    <ClCompile Include="file_system_tests.cpp" />
   </ItemGroup>
 </Project>

src/common-tests/file_system_tests.cpp

@@ -0,0 +1,25 @@
+#include "common/file_system.h"
+#include <gtest/gtest.h>
+
+TEST(FileSystem, IsAbsolutePath)
+{
+#ifdef WIN32
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("C:\\"));
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("C:\\Path"));
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("C:\\Path\\Subdirectory"));
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("C:/"));
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("C:/Path"));
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("C:/Path/Subdirectory"));
+  ASSERT_FALSE(FileSystem::IsAbsolutePath(""));
+  ASSERT_FALSE(FileSystem::IsAbsolutePath("C:"));
+  ASSERT_FALSE(FileSystem::IsAbsolutePath("Path"));
+  ASSERT_FALSE(FileSystem::IsAbsolutePath("Path/Subdirectory"));
+#else
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("/"));
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("/path"));
+  ASSERT_TRUE(FileSystem::IsAbsolutePath("/path/subdirectory"));
+  ASSERT_FALSE(FileSystem::IsAbsolutePath(""));
+  ASSERT_FALSE(FileSystem::IsAbsolutePath("path"));
+  ASSERT_FALSE(FileSystem::IsAbsolutePath("path/subdirectory"));
+#endif
+}

src/common/file_system.cpp

@@ -230,6 +230,16 @@ void SanitizeFileName(String& Destination, bool StripSlashes /* = true */)
   return SanitizeFileName(Destination, Destination, StripSlashes);
 }
 
+bool IsAbsolutePath(const std::string_view& path)
+{
+#ifdef WIN32
+  return (path.length() >= 3 && ((path[0] >= 'A' && path[0] <= 'Z') || (path[0] >= 'a' && path[0] <= 'z')) &&
+          path[1] == ':' && (path[2] == '/' || path[2] == '\\'));
+#else
+  return (path.length() >= 1 && path[0] == '/');
+#endif
+}
+
 std::string ReplaceExtension(std::string_view path, std::string_view new_extension)
 {
   std::string_view::size_type pos = path.rfind('.');

src/common/file_system.h

@@ -137,6 +137,9 @@ void SanitizeFileName(char* Destination, u32 cbDestination, const char* FileName
 void SanitizeFileName(String& Destination, const char* FileName, bool StripSlashes = true);
 void SanitizeFileName(String& Destination, bool StripSlashes = true);
 
+/// Returns true if the specified path is an absolute path (C:\Path on Windows or /path on Unix).
+bool IsAbsolutePath(const std::string_view& path);
+
 /// Replaces the extension of a filename with another.
 std::string ReplaceExtension(std::string_view path, std::string_view new_extension);