lib/file: Implement insertByte function

src/lib/file.cpp

@@ -26,7 +26,7 @@
 
 File::File(std::string path, char mode, uint64_t cursorPosition): mode(mode), path(path), cursorPosition(cursorPosition){
     std::filesystem::path filePath = path;
-    if(this->mode == 'w' || this->mode == 'a'){
+    if(this->mode == 'w' || (this->mode == 'a' && !std::filesystem::exists(filePath))){
         this->size = ErrorOr<uint64_t>(0);
     }else{
         this->size = ErrorOr<uint64_t>(std::filesystem::file_size(filePath));
@@ -43,11 +43,12 @@ File::~File() {
 void File::open(){
     switch(this->mode){
         case 'w':
-        case 'm':
             this->fileStream.open(this->path, std::fstream::out | std::fstream::binary);
             break;
+        case 'm':
+            this->fileStream.open(this->path, std::fstream::out | std::fstream::in | std::fstream::binary);
+            break;
         case 'r':
-        case 'e':
             this->fileStream.open(this->path, std::fstream::in | std::fstream::binary);
             break;
         case 'a':
@@ -57,6 +58,8 @@ void File::open(){
             break;
     }
 
+    std::filesystem::path filePath = this->path;
+    this->size = ErrorOr<uint64_t>(std::filesystem::file_size(filePath));
     this->isOpen = this->fileStream.is_open();
 }
 
@@ -169,6 +172,27 @@ ErrorOrVoid File::writeString(tiny_utf8::string data){
     return failure ? ErrorOrVoid(true, ErrorCodes::UNKNOWN) : ErrorOrVoid();
 }
 
+// Naive implementation of insertByte
+ErrorOrVoid File::insertByte(uint8_t byte){
+    bool failure = false;
+
+    try{
+        uint8_t* buffer = new uint8_t[this->size.value];
+        std::vector<uint8_t> readData;
+
+        this->fileStream.read(reinterpret_cast<char*>(buffer), this->size.value);
+        readData = std::vector<uint8_t>(buffer, buffer+this->size.value);
+
+        readData.insert(readData.begin()+this->cursorPosition, byte);
+        this->fileStream.seekg(0);
+        this->write(readData);
+        
+    }catch(std::exception& e){
+        failure = true;
+    }
+    return failure ? ErrorOrVoid(true, ErrorCodes::UNKNOWN) : ErrorOrVoid();
+}
+
 ErrorOr<File*> File::open(std::string path, char mode, uint64_t startPosition){
     if (!std::filesystem::exists(path) && (mode == 'r' || mode == 'm')) {
         return ErrorOr<File*>(true, ErrorCodes::FILE_NOT_FOUND, nullptr);

src/lib/file.hpp

@@ -85,7 +85,6 @@ class File {
         //  w (write: overwrite file deleting its previous contents)
         //  a (append: write to end of file)
         //  m (modify: write to file modifying its previous contents)
-        //  e (edit: like read+modify)
         //
         // A startPosition of 0xFFFFFFFF is considered to be the end of
         // the file whatever its size.

src/test/file.cpp

@@ -54,6 +54,7 @@ int main(){
 
     readFile = File::open("resources/writeTest", 'r').value;
     uint8_t testByte = readFile->readByte().value;
+    readFile->close();
     ASSERT(testByte == 'a');
     std::cout << "Passed write byte test." << std::endl;
 
@@ -62,8 +63,10 @@ int main(){
     writeFile->write(std::vector<uint8_t>({'a', 'b', 'c'}));
     writeFile->close();
 
+    readFile->open();
     readFile->cursorPosition = 0;
     tiny_utf8::string testBytes = readFile->readString(3).value;
+    readFile->close();
     ASSERT(testBytes == "abc");
     std::cout << "Passed write test." << std::endl;
 
@@ -71,8 +74,68 @@ int main(){
     writeFile->writeString(tiny_utf8::string("Hallo"));
     writeFile->close();
 
+    readFile->open();
     readFile->cursorPosition = 0;
     tiny_utf8::string testString = readFile->readString(5).value;
+    readFile->close();
     ASSERT(testString == "Hallo");
     std::cout << "Passed write string test." << std::endl;
+
+    delete writeFile;
+
+    File *appendFile;
+
+    appendFile = File::open("resources/writeTest", 'a').value;
+    appendFile->writeByte(',');
+    appendFile->close();
+
+    readFile->open();
+    readFile->cursorPosition = 0;
+    tiny_utf8::string appendByteString = readFile->readString(readFile->size.value).value;
+    readFile->close();
+
+    ASSERT(appendByteString == "Hallo,");
+    std::cout << "Passed append byte test." << std::endl;
+
+    appendFile->open();
+    appendFile->write(std::vector<uint8_t>({' ', 'I', 'c', 'h'}));
+    appendFile->close();
+
+    readFile->open();
+    readFile->cursorPosition = 0;
+    tiny_utf8::string appendBytesString = readFile->readString(readFile->size.value).value;
+    readFile->close();
+
+    ASSERT(appendBytesString == "Hallo, Ich");
+    std::cout << "Passed append test" << std::endl;
+
+    appendFile->open();
+    appendFile->writeString(" bin Shwoomple.");
+    appendFile->close();
+
+    readFile->open();
+    readFile->cursorPosition = 0;
+    tiny_utf8::string appendString = readFile->readString(readFile->size.value).value;
+    readFile->close();
+
+    ASSERT(appendString == "Hallo, Ich bin Shwoomple.");
+    std::cout << "Passed append string test" << std::endl;
+
+    delete appendFile;
+
+    File *modifyFile;
+
+    modifyFile = File::open("resources/writeTest", 'm').value;
+
+    modifyFile->cursorPosition = 5;
+    modifyFile->insertByte(',');
+    modifyFile->close();
+
+    readFile->open();
+    readFile->cursorPosition = 0;
+    tiny_utf8::string modifyByteString = readFile->readString(readFile->size.value).value;
+    readFile->close();
+
+    ASSERT(modifyByteString == "Hallo,, Ich bin Shwoomple.");
+    std::cout << "Passed modify byte test" << std::endl;
 }