diff --git a/src/lib/file.cpp b/src/lib/file.cpp
index 912fd1f..9ec7461 100644
--- a/src/lib/file.cpp
+++ b/src/lib/file.cpp
@@ -27,22 +27,7 @@
 File::File(std::string path, char mode, uint64_t cursorPosition): mode(mode), path(path), cursorPosition(cursorPosition){
     std::filesystem::path filePath = path;
     this->size = ErrorOr<uint64_t>(std::filesystem::file_size(filePath));
-
-    switch(this->mode){
-        case 'w':
-        case 'm':
-            this->fileStream.open(path, std::fstream::out | std::fstream::binary);
-            break;
-        case 'r':
-        case 'e':
-            this->fileStream.open(path, std::fstream::in | std::fstream::binary);
-            break;
-        case 'a':
-            this->fileStream.open(path, std::fstream::app | std::fstream::binary);
-            break;
-        default:
-            break;
-    }
+    this->open();
     this->isOpen = true;
     this->eof = false;
 }
@@ -73,29 +58,20 @@ void File::close(){
 }
 
 ErrorOr<uint8_t> File::readByte(){
-    if(this->size.isError){
-        return ErrorOr<uint8_t>(true, this->size.errorCode);
-    }
-
-    this->cursorPosition += 1;
     this->fileStream.seekg(this->cursorPosition);
 
     char* byte = new char;
     try{
         this->fileStream.read(byte, 1);
-        delete byte;
     }catch(std::exception& e){
         return ErrorOr<uint8_t>(true, ErrorCodes::FILE_READ_FAILED);
     }
+
+    this->cursorPosition += 1;
     return ErrorOr<uint8_t>((uint8_t) *byte);
 }
 
 ErrorOr<std::vector<uint8_t>> File::read(uint64_t bytes){
-    if(this->size.isError){
-        return ErrorOr<std::vector<uint8_t>>(true, this->size.errorCode);
-    }
-
-    this->cursorPosition += 1;
     this->fileStream.seekg(this->cursorPosition);
 
     char* buffer = new char[bytes];
@@ -109,14 +85,11 @@ ErrorOr<std::vector<uint8_t>> File::read(uint64_t bytes){
     }catch(std::exception& e){
         return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::FILE_READ_FAILED);
     }
+    this->cursorPosition += bytes;
     return ErrorOr<std::vector<uint8_t>>(data);
 }
 
 ErrorOr<tiny_utf8::string> File::readString(uint64_t bytes){
-    if(this->size.isError){
-        return ErrorOr<tiny_utf8::string>(true, this->size.errorCode);
-    }
-
     ErrorOr<std::vector<uint8_t>> data = this->read(bytes);
     if(data.isError){
         return ErrorOr<tiny_utf8::string>(true, data.errorCode);
diff --git a/src/test/file.cpp b/src/test/file.cpp
index 214f7c4..3701cc4 100644
--- a/src/test/file.cpp
+++ b/src/test/file.cpp
@@ -13,6 +13,7 @@
 // version 3 along with this program.
 // If not, see https://www.gnu.org/licenses/agpl-3.0.en.html
 
+#include <vector>
 #include "assert.hpp"
 #include "tinyutf8/tinyutf8.h"
 #include "../lib/file.hpp"
@@ -23,10 +24,19 @@ int main(){
     std::cout << "################################################################################" << std::endl;
     File* file;
 
-    //read test
+    //readByte test
     file = File::open("resources/unicode_data/normal_utf-8", 'r').value;
-    tiny_utf8::string data = file->readString(file->size.value).value;
-    std::cout << file->size.isError << std::endl;
-    std::cout << data << std::endl;
+    uint8_t byte = file->readByte().value;
+    ASSERT(byte == 'T');
+    std::cout << "Passed read byte test." << std::endl;
 
+    //read test
+    std::vector<uint8_t> bytes = file->read(5).value;
+    //cursorPosition has already moved forward by one
+    ASSERT(bytes == std::vector<uint8_t>({'e', 's', 't', ' ', 's'}));
+    std::cout << "Passed read test." << std::endl;
+
+    //readString test
+    tiny_utf8::string data = file->readString(5).value;
+    std::cout << data << std::endl;
 }