4 files changed, 50 insertions, 32 deletions

diff --git a/src/common/fs/file.cpp b/src/common/fs/file.cpp
index 9f3de1cb0..077f34995 100644
--- a/src/common/fs/file.cpp
+++ b/src/common/fs/file.cpp
@@ -172,7 +172,7 @@ std::string ReadStringFromFile(const std::filesystem::path& path, FileType type)
 
 size_t WriteStringToFile(const std::filesystem::path& path, FileType type,
                          std::string_view string) {
-    if (!IsFile(path)) {
+    if (Exists(path) && !IsFile(path)) {
         return 0;
     }
 
@@ -183,11 +183,7 @@ size_t WriteStringToFile(const std::filesystem::path& path, FileType type,
 
 size_t AppendStringToFile(const std::filesystem::path& path, FileType type,
                           std::string_view string) {
-    if (!Exists(path)) {
-        return WriteStringToFile(path, type, string);
-    }
-
-    if (!IsFile(path)) {
+    if (Exists(path) && !IsFile(path)) {
         return 0;
     }
 
@@ -309,7 +305,11 @@ bool IOFile::Flush() const {
 
     errno = 0;
 
-    const auto flush_result = std::fflush(file) == 0;
+#ifdef _WIN32
+    const auto flush_result = std::fflush(file) == 0 && _commit(fileno(file)) == 0;
+#else
+    const auto flush_result = std::fflush(file) == 0 && fsync(fileno(file)) == 0;
+#endif
 
     if (!flush_result) {
         const auto ec = std::error_code{errno, std::generic_category()};
diff --git a/src/common/fs/file.h b/src/common/fs/file.h
index 50e270c5b..588fe619d 100644
--- a/src/common/fs/file.h
+++ b/src/common/fs/file.h
@@ -49,7 +49,7 @@ void OpenFileStream(FileStream& file_stream, const Path& path, std::ios_base::op
 
 /**
  * Reads an entire file at path and returns a string of the contents read from the file.
- * If the filesystem object at path is not a file, this function returns an empty string.
+ * If the filesystem object at path is not a regular file, this function returns an empty string.
  *
  * @param path Filesystem path
  * @param type File type
@@ -71,8 +71,9 @@ template <typename Path>
 
 /**
  * Writes a string to a file at path and returns the number of characters successfully written.
- * If an file already exists at path, its contents will be erased.
- * If the filesystem object at path is not a file, this function returns 0.
+ * If a file already exists at path, its contents will be erased.
+ * If a file does not exist at path, it creates and opens a new empty file for writing.
+ * If the filesystem object at path exists and is not a regular file, this function returns 0.
  *
  * @param path Filesystem path
  * @param type File type
@@ -95,8 +96,8 @@ template <typename Path>
 
 /**
  * Appends a string to a file at path and returns the number of characters successfully written.
- * If a file does not exist at path, WriteStringToFile is called instead.
- * If the filesystem object at path is not a file, this function returns 0.
+ * If a file does not exist at path, it creates and opens a new empty file for appending.
+ * If the filesystem object at path exists and is not a regular file, this function returns 0.
  *
  * @param path Filesystem path
  * @param type File type
@@ -395,11 +396,11 @@ public:
     [[nodiscard]] size_t WriteString(std::span<const char> string) const;
 
     /**
-     * Flushes any unwritten buffered data into the file.
+     * Attempts to flush any unwritten buffered data into the file and flush the file into the disk.
      *
      * @returns True if the flush was successful, false otherwise.
      */
-    [[nodiscard]] bool Flush() const;
+    bool Flush() const;
 
     /**
      * Resizes the file to a given size.
diff --git a/src/common/fs/fs.cpp b/src/common/fs/fs.cpp
index d492480d9..9089cad67 100644
--- a/src/common/fs/fs.cpp
+++ b/src/common/fs/fs.cpp
@@ -135,8 +135,9 @@ std::shared_ptr<IOFile> FileOpen(const fs::path& path, FileAccessMode mode, File
         return nullptr;
     }
 
-    if (!IsFile(path)) {
-        LOG_ERROR(Common_Filesystem, "Filesystem object at path={} is not a file",
+    if (Exists(path) && !IsFile(path)) {
+        LOG_ERROR(Common_Filesystem,
+                  "Filesystem object at path={} exists and is not a regular file",
                   PathToUTF8String(path));
         return nullptr;
     }
@@ -321,7 +322,8 @@ bool RemoveDirContentsRecursively(const fs::path& path) {
 
     std::error_code ec;
 
-    for (const auto& entry : fs::recursive_directory_iterator(path, ec)) {
+    // TODO (Morph): Replace this with recursive_directory_iterator once it's fixed in MSVC.
+    for (const auto& entry : fs::directory_iterator(path, ec)) {
         if (ec) {
             LOG_ERROR(Common_Filesystem,
                       "Failed to completely enumerate the directory at path={}, ec_message={}",
@@ -337,6 +339,12 @@ bool RemoveDirContentsRecursively(const fs::path& path) {
                       PathToUTF8String(entry.path()), ec.message());
             break;
         }
+
+        // TODO (Morph): Remove this when MSVC fixes recursive_directory_iterator.
+        // recursive_directory_iterator throws an exception despite passing in a std::error_code.
+        if (entry.status().type() == fs::file_type::directory) {
+            return RemoveDirContentsRecursively(entry.path());
+        }
     }
 
     if (ec) {
@@ -475,7 +483,8 @@ void IterateDirEntriesRecursively(const std::filesystem::path& path,
 
     std::error_code ec;
 
-    for (const auto& entry : fs::recursive_directory_iterator(path, ec)) {
+    // TODO (Morph): Replace this with recursive_directory_iterator once it's fixed in MSVC.
+    for (const auto& entry : fs::directory_iterator(path, ec)) {
         if (ec) {
             break;
         }
@@ -495,6 +504,12 @@ void IterateDirEntriesRecursively(const std::filesystem::path& path,
                 break;
             }
         }
+
+        // TODO (Morph): Remove this when MSVC fixes recursive_directory_iterator.
+        // recursive_directory_iterator throws an exception despite passing in a std::error_code.
+        if (entry.status().type() == fs::file_type::directory) {
+            IterateDirEntriesRecursively(entry.path(), callback, filter);
+        }
     }
 
     if (callback_error || ec) {
diff --git a/src/common/fs/fs.h b/src/common/fs/fs.h
index f6f256349..183126de3 100644
--- a/src/common/fs/fs.h
+++ b/src/common/fs/fs.h
@@ -48,18 +48,18 @@ template <typename Path>
  *
  * Failures occur when:
  * - Input path is not valid
- * - Filesystem object at path is not a file
+ * - Filesystem object at path is not a regular file
  * - Filesystem at path is read only
  *
  * @param path Filesystem path
  *
  * @returns True if file removal succeeds or file does not exist, false otherwise.
  */
-[[nodiscard]] bool RemoveFile(const std::filesystem::path& path);
+bool RemoveFile(const std::filesystem::path& path);
 
 #ifdef _WIN32
 template <typename Path>
-[[nodiscard]] bool RemoveFile(const Path& path) {
+bool RemoveFile(const Path& path) {
     if constexpr (IsChar<typename Path::value_type>) {
         return RemoveFile(ToU8String(path));
     } else {
@@ -74,7 +74,7 @@ template <typename Path>
  * Failures occur when:
  * - One or both input path(s) is not valid
  * - Filesystem object at old_path does not exist
- * - Filesystem object at old_path is not a file
+ * - Filesystem object at old_path is not a regular file
  * - Filesystem object at new_path exists
  * - Filesystem at either path is read only
  *
@@ -110,8 +110,8 @@ template <typename Path1, typename Path2>
  *
  * Failures occur when:
  * - Input path is not valid
- * - Filesystem object at path is not a file
- * - The file is not opened
+ * - Filesystem object at path exists and is not a regular file
+ * - The file is not open
  *
  * @param path Filesystem path
  * @param mode File access mode
@@ -251,11 +251,11 @@ template <typename Path>
  *
  * @returns True if directory removal succeeds or directory does not exist, false otherwise.
  */
-[[nodiscard]] bool RemoveDir(const std::filesystem::path& path);
+bool RemoveDir(const std::filesystem::path& path);
 
 #ifdef _WIN32
 template <typename Path>
-[[nodiscard]] bool RemoveDir(const Path& path) {
+bool RemoveDir(const Path& path) {
     if constexpr (IsChar<typename Path::value_type>) {
         return RemoveDir(ToU8String(path));
     } else {
@@ -276,11 +276,11 @@ template <typename Path>
  *
  * @returns True if the directory and all of its contents are removed successfully, false otherwise.
  */
-[[nodiscard]] bool RemoveDirRecursively(const std::filesystem::path& path);
+bool RemoveDirRecursively(const std::filesystem::path& path);
 
 #ifdef _WIN32
 template <typename Path>
-[[nodiscard]] bool RemoveDirRecursively(const Path& path) {
+bool RemoveDirRecursively(const Path& path) {
     if constexpr (IsChar<typename Path::value_type>) {
         return RemoveDirRecursively(ToU8String(path));
     } else {
@@ -301,11 +301,11 @@ template <typename Path>
  *
  * @returns True if all of the directory's contents are removed successfully, false otherwise.
  */
-[[nodiscard]] bool RemoveDirContentsRecursively(const std::filesystem::path& path);
+bool RemoveDirContentsRecursively(const std::filesystem::path& path);
 
 #ifdef _WIN32
 template <typename Path>
-[[nodiscard]] bool RemoveDirContentsRecursively(const Path& path) {
+bool RemoveDirContentsRecursively(const Path& path) {
     if constexpr (IsChar<typename Path::value_type>) {
         return RemoveDirContentsRecursively(ToU8String(path));
     } else {
@@ -435,11 +435,13 @@ template <typename Path>
 #endif
 
 /**
- * Returns whether a filesystem object at path is a file.
+ * Returns whether a filesystem object at path is a regular file.
+ * A regular file is a file that stores text or binary data.
+ * It is not a directory, symlink, FIFO, socket, block device, or character device.
  *
  * @param path Filesystem path
  *
- * @returns True if a filesystem object at path is a file, false otherwise.
+ * @returns True if a filesystem object at path is a regular file, false otherwise.
  */
 [[nodiscard]] bool IsFile(const std::filesystem::path& path);