lib/file.cpp: Implement cutByte function

src/lib/file.cpp

@@ -187,7 +187,7 @@ ErrorOrVoid File::insertByte(uint8_t byte){
         this->fileStream.seekg(0);
         this->write(readData);
         this->cursorPosition++;
-        
+        delete buffer;
     }catch(std::exception& e){
         failure = true;
     }
@@ -209,7 +209,7 @@ ErrorOrVoid File::insert(std::vector<uint8_t> data){
         this->fileStream.seekg(0);
         this->write(readData);
         this->cursorPosition += data.size();
-        
+        delete buffer;
     }catch(std::exception& e){
         failure = true;
     }
@@ -233,13 +233,36 @@ ErrorOrVoid File::insertString(tiny_utf8::string string){
         //TODO: fix hack. tinyutf8 appends "_utf-8" when readData is assigned: tiny_utf8::string((char *) buffer);
         this->writeString(readData.substr(0, readData.find("_utf-8")));
         this->cursorPosition += string.size();
-        
+        delete buffer;
     }catch(std::exception& e){
         failure = true;
     }
     return failure ? ErrorOrVoid(true, ErrorCodes::UNKNOWN) : ErrorOrVoid();
 }
 
+ErrorOr<uint8_t> File::cutByte(){
+    bool failure = false;
+    uint8_t byte;
+    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);
+
+        byte = readData[this->cursorPosition];
+        readData.erase(readData.begin() + this->cursorPosition);
+
+        this->fileStream.seekg(0);
+        this->write(readData);
+        this->cursorPosition++;
+        delete buffer;
+    }catch(std::exception& e){
+        failure = true;
+    }
+    return failure ? ErrorOr<uint8_t>(true, ErrorCodes::UNKNOWN) : ErrorOr<uint8_t>(byte);
+}
+
 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/test/file.cpp

@@ -123,6 +123,7 @@ int main(){
 
     delete appendFile;
 
+    //test insert functions
     File *modifyFile;
 
     modifyFile = File::open("resources/writeTest", 'm').value;
@@ -164,4 +165,19 @@ int main(){
 
     ASSERT(modifyString == "Hallo, Hi THE CAKE IS A LIE, Ich bin Shwoomple.");
     std::cout << "Passed modify string test" << std::endl;
+
+    //test cut functions
+    modifyFile->open();
+    modifyFile->cursorPosition = modifyFile->size.value-1;
+    ErrorOr<uint8_t> cutByte = modifyFile->cutByte();
+    modifyFile->close();
+
+    readFile->open();
+    readFile->cursorPosition = 0;
+    tiny_utf8::string cutByteString = readFile->readString(readFile->size.value).value;
+    readFile->close();    
+
+    ASSERT(cutByte.value == '.');
+    ASSERT(cutByteString == "Hallo, Hi THE CAKE IS A LIE, Ich bin Shwoomple");
+    std::cout << "Passed cut byte test." << std::endl;
 }