move multipart support to separate crate

actix-multipart/src/error.rs

@@ -0,0 +1,46 @@
+//! Error and Result module
+use actix_web::error::{ParseError, PayloadError};
+use actix_web::http::StatusCode;
+use actix_web::{HttpResponse, ResponseError};
+use derive_more::{Display, From};
+
+/// A set of errors that can occur during parsing multipart streams
+#[derive(Debug, Display, From)]
+pub enum MultipartError {
+    /// Content-Type header is not found
+    #[display(fmt = "No Content-type header found")]
+    NoContentType,
+    /// Can not parse Content-Type header
+    #[display(fmt = "Can not parse Content-Type header")]
+    ParseContentType,
+    /// Multipart boundary is not found
+    #[display(fmt = "Multipart boundary is not found")]
+    Boundary,
+    /// Multipart stream is incomplete
+    #[display(fmt = "Multipart stream is incomplete")]
+    Incomplete,
+    /// Error during field parsing
+    #[display(fmt = "{}", _0)]
+    Parse(ParseError),
+    /// Payload error
+    #[display(fmt = "{}", _0)]
+    Payload(PayloadError),
+}
+
+/// Return `BadRequest` for `MultipartError`
+impl ResponseError for MultipartError {
+    fn error_response(&self) -> HttpResponse {
+        HttpResponse::new(StatusCode::BAD_REQUEST)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_multipart_error() {
+        let resp: HttpResponse = MultipartError::Boundary.error_response();
+        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
+    }
+}