Refactor file write APIs to use std::string_view and std::span<const char>

Updated test cases and C API implementations to use std::string_view for writeAll calls and std::span<const char> for byte data, improving type safety and consistency with modern C++ practices.

Author: Geenz

Tests/VirtualFileSystem/VFSSimpleTest.cpp

@@ -26,7 +26,7 @@ int main() {
 
     // Write
     std::cout << "Calling writeAll...\n";
-    auto w = fh.writeAll("Hello from simple test!\n");
+    auto w = fh.writeAll(std::string_view("Hello from simple test!\n"));
     std::cout << "Waiting for write...\n";
     w.wait();
     std::cout << "Write status: " << static_cast<int>(w.status()) << "\n";

Tests/VirtualFileSystem/VFSTests.cpp

@@ -22,7 +22,7 @@ TEST(VFS, WriteReadDelete_InTempDir) {
     const std::string text = "Hello from VFSTests!\n";
 
     // Write
-    auto w = fh.writeAll(text);
+    auto w = fh.writeAll(std::string_view(text));
     w.wait();
     ASSERT_EQ(w.status(), FileOpStatus::Complete) << "writeAll failed: " << w.errorInfo().message;
     EXPECT_EQ(w.bytesWritten(), static_cast<uint64_t>(text.size()));
@@ -47,7 +47,7 @@ TEST(VFS, ListTempDir_ShowsCreatedFile) {
     auto filePath = tmp.join("file.txt");
     auto fh = env.vfs().createFileHandle(filePath.string());
 
-    auto w = fh.writeAll("x");
+    auto w = fh.writeAll(std::string_view("x"));
     w.wait();
     ASSERT_EQ(w.status(), FileOpStatus::Complete) << "writeAll failed: " << w.errorInfo().message;
 

Tests/VirtualFileSystem/VFSTextFidelityTests.cpp

@@ -46,7 +46,7 @@ TEST(VFSTextFidelity, WriteLine_BeyondEOF_ExtendsAndWrites) {
     auto fh = vfs.createFileHandle(path);
 
     // Start with one line
-    auto w0 = fh.writeAll("root\n");
+    auto w0 = fh.writeAll(std::string_view("root\n"));
     w0.wait();
     ASSERT_EQ(w0.status(), FileOpStatus::Complete);
 

src/entropy/entropy_file_handle_c.cpp

@@ -235,7 +235,7 @@ entropy_FileOperationHandle entropy_file_handle_write_all_bytes(
 
     try {
         auto* cpp_handle = reinterpret_cast<FileHandle*>(handle);
-        std::span<const std::byte> data(reinterpret_cast<const std::byte*>(bytes), length);
+        std::span<const char> data(reinterpret_cast<const char*>(bytes), length);
         FileOperationHandle op = cpp_handle->writeAll(data);
         *status = ENTROPY_OK;
         return wrap_file_operation_handle(std::move(op));
@@ -260,7 +260,7 @@ entropy_FileOperationHandle entropy_file_handle_write_all_bytes_with_options(
 
     try {
         auto* cpp_handle = reinterpret_cast<FileHandle*>(handle);
-        std::span<const std::byte> data(reinterpret_cast<const std::byte*>(bytes), length);
+        std::span<const char> data(reinterpret_cast<const char*>(bytes), length);
         WriteOptions wo = to_cpp_write_options(options);
         FileOperationHandle op = cpp_handle->writeAll(data, wo);
         *status = ENTROPY_OK;
@@ -286,7 +286,7 @@ entropy_FileOperationHandle entropy_file_handle_write_range(
 
     try {
         auto* cpp_handle = reinterpret_cast<FileHandle*>(handle);
-        std::span<const std::byte> data(reinterpret_cast<const std::byte*>(bytes), length);
+        std::span<const char> data(reinterpret_cast<const char*>(bytes), length);
         FileOperationHandle op = cpp_handle->writeRange(offset, data);
         *status = ENTROPY_OK;
         return wrap_file_operation_handle(std::move(op));