Change end-to-end test to use &[u8] instead of Vec<u8>

tests/end_to_end.rs

@@ -7,20 +7,19 @@ use std::io::Cursor;
 // This test asserts that after creating a zip file, then reading its contents back out,
 // the extracted data will *always* be exactly the same as the original data.
 #[test]
-fn main() -> zip::result::ZipResult<()> {
-    let buf: &mut Vec<u8> = &mut Vec::new();
+fn main() {
+    // TODO: The buffer length is tied to the LOREM_IPSUM length currently
+    let buf: &mut [u8] = &mut [0u8; 760];
     let mut file = Cursor::new(buf);
 
-    write_to_zip_file(&mut file)?;
+    write_to_zip_file(&mut file).expect("file written");
 
     let file_contents: String = read_zip_file(file).unwrap();
 
     assert!(file_contents.as_bytes() == LOREM_IPSUM);
-
-    Ok(())
 }
 
-fn write_to_zip_file(file: &mut Cursor<&mut Vec<u8>>) -> zip::result::ZipResult<()> {
+fn write_to_zip_file(file: &mut Cursor<&mut [u8]>) -> zip::result::ZipResult<()> {
     let mut zip = zip::ZipWriter::new(file);
 
     zip.add_directory("test/", FileOptions::default())?;
@@ -38,7 +37,7 @@ fn write_to_zip_file(file: &mut Cursor<&mut Vec<u8>>) -> zip::result::ZipResult<
     Ok(())
 }
 
-fn read_zip_file(zip_file: Cursor<&mut Vec<u8>>) -> zip::result::ZipResult<String> {
+fn read_zip_file(zip_file: Cursor<&mut [u8]>) -> zip::result::ZipResult<String> {
     let mut archive = zip::ZipArchive::new(zip_file).unwrap();
 
     let mut file = archive.by_name("test/lorem_ipsum.txt")?;