Fix exact write

CHANGELOG.md

@@ -8,6 +8,7 @@
 ### Fixes
 
 * Fix bug where buffering chunked body writer could return `Ok(0)` on calls to `write()` ([#81](https://github.com/drogue-iot/reqwless/pull/81))
+* Fix bug in buffering chunked body writer where a call to `write()` with a buffer length exactly matching the remaining size of the remainder of the current chunk causes the entire chunk to be discarded ([#85](https://github.com/drogue-iot/reqwless/pull/85))
 
 ## v0.12 (2024-05-23)
 

src/body_writer/buffering_chunked.rs

@@ -117,6 +117,10 @@ where
  self.pos = self.header_pos + self.allocated_header;
  }
 
+ fn current_chunk_is_full(&self) -> bool {
+ self.pos + NEWLINE.len() == self.buf.len()
+ }
+
  async fn emit_buffered(&mut self) -> Result<(), C::Error> {
  self.conn.write_all(&self.buf[..self.header_pos]).await?;
  self.header_pos = 0;
@@ -149,7 +153,7 @@ where
  self.emit_buffered().await.map_err(|e| e.kind())?;
  written = self.append_current_chunk(buf);
  }
- if written < buf.len() {
+ if self.current_chunk_is_full() {
  self.finish_current_chunk();
  self.emit_buffered().await.map_err(|e| e.kind())?;
  }
@@ -330,19 +334,36 @@ mod tests {
  }
 
  #[tokio::test]
- async fn current_chunk_is_emitted_before_empty_chunk_is_emitted() {
+ async fn written_bytes_fit_exactly() {
  // Given
  let mut conn = Vec::new();
  let mut buf = [0; 14];
  buf[..5].copy_from_slice(b"HELLO");
 
  // When
  let mut writer = BufferingChunkedBodyWriter::new_with_data(&mut conn, &mut buf, 5);
+ writer.write_all(b"BODY").await.unwrap(); // Can fit exactly
  writer.write_all(b"BODY").await.unwrap(); // Can fit
+ writer.terminate().await.unwrap(); // Can fit
+
+ // Then
+ assert_eq!(b"HELLO4\r\nBODY\r\n4\r\nBODY\r\n0\r\n\r\n", conn.as_slice());
+ }
+
+ #[tokio::test]
+ async fn current_chunk_is_emitted_on_termination_before_empty_chunk_is_emitted() {
+ // Given
+ let mut conn = Vec::new();
+ let mut buf = [0; 14];
+ buf[..5].copy_from_slice(b"HELLO");
+
+ // When
+ let mut writer = BufferingChunkedBodyWriter::new_with_data(&mut conn, &mut buf, 5);
+ writer.write_all(b"BOD").await.unwrap(); // Can fit
  writer.terminate().await.unwrap(); // Cannot fit
 
  // Then
- assert_eq!(b"HELLO4\r\nBODY\r\n0\r\n\r\n", conn.as_slice());
+ assert_eq!(b"HELLO3\r\nBOD\r\n0\r\n\r\n", conn.as_slice());
  }
 
  #[tokio::test]