refactor: add lift (#2472)

Co-authored-by: Kiryl Mialeshka <[email protected]>

src/core/jit/error.rs

@@ -2,6 +2,8 @@ use async_graphql::parser::types::OperationType;
 use async_graphql::{ErrorExtensions, PathSegment, Pos, Positioned, ServerError};
 use thiserror::Error;
 
+use crate::core::lift::Lift;
+
 #[derive(Error, Debug, Clone, PartialEq, Eq)]
 #[error("Error while building the plan")]
 pub enum BuildError {
@@ -78,14 +80,8 @@ impl Error {
 
         server_error
     }
-}
 
-pub trait IntoServerError {
-    fn into_server_error(self) -> ServerError;
-}
-
-impl IntoServerError for Error {
-    fn into_server_error(self) -> ServerError {
+    pub fn into_server_error(self) -> ServerError {
         match self {
             // async_graphql::parser::Error has special conversion to ServerError
             Error::ParseError(error) => error.into(),
@@ -94,12 +90,13 @@ impl IntoServerError for Error {
     }
 }
 
-impl IntoServerError for Positioned<Error> {
-    fn into_server_error(self) -> ServerError {
-        match self.node {
+impl From<Positioned<Error>> for Lift<ServerError> {
+    fn from(a: Positioned<Error>) -> Self {
+        (match a.node {
             // async_graphql::parser::Error already has builtin positioning
             Error::ParseError(error) => error.into(),
-            error => error.into_server_error_with_pos(Some(self.pos)),
-        }
+            error => error.into_server_error_with_pos(Some(a.pos)),
+        })
+        .into()
     }
 }

src/core/jit/graphql_executor.rs

@@ -4,7 +4,6 @@ use std::sync::Arc;
 use async_graphql::{Data, Executor, Response};
 use futures_util::stream::BoxStream;
 
-use super::IntoServerError;
 use crate::core::app_context::AppContext;
 use crate::core::http::RequestContext;
 use crate::core::jit;

src/core/jit/response.rs

@@ -1,9 +1,9 @@
-use async_graphql::Positioned;
+use async_graphql::{Positioned, ServerError};
 use derive_setters::Setters;
 use serde::Serialize;
 
-use super::IntoServerError;
 use crate::core::jit;
+use crate::core::lift::Lift;
 
 #[derive(Setters, Serialize)]
 pub struct Response<Value, Error> {
@@ -35,7 +35,7 @@ impl Response<async_graphql::Value, jit::Error> {
             resp = resp.extension(name, value);
         }
         for error in self.errors {
-            resp.errors.push(error.into_server_error());
+            resp.errors.push(Lift::<ServerError>::from(error).take());
         }
         resp
     }

src/core/lift.rs

@@ -0,0 +1,24 @@
+use std::ops::Deref;
+
+///
+/// Just an empty wrapper around a value used to implement `From` for foreign
+/// types.
+pub struct Lift<A>(A);
+impl<A> Deref for Lift<A> {
+    type Target = A;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<A> Lift<A> {
+    pub fn take(self) -> A {
+        self.0
+    }
+}
+
+impl<A> From<A> for Lift<A> {
+    fn from(a: A) -> Self {
+        Lift(a)
+    }
+}

src/core/mod.rs

@@ -21,6 +21,7 @@ pub mod http;
 pub mod ir;
 pub mod jit;
 pub mod json;
+mod lift;
 pub mod merge_right;
 pub mod mustache;
 pub mod path;